https://wiki.archlinux.org/api.php?action=feedcontributions&user=SYSMAN&feedformat=atomArchWiki - User contributions [en]2024-03-29T06:20:27ZUser contributionsMediaWiki 1.41.0https://wiki.archlinux.org/index.php?title=GRUB&diff=195256GRUB2012-04-19T12:45:16Z<p>SYSMAN: /* Install to UEFI SYSTEM PARTITION */ initial space reqd. on second line of each grub-install command</p>
<hr />
<div>[[Category:Boot loaders (English)]]<br />
{{i18n|GRUB2}}<br />
[[fr:GRUB2]]<br />
{{Article summary start}}<br />
{{Article summary text|Covers various aspects of the next generation of the GRand Unified Bootloader (GRUB2).}}<br />
{{Article summary heading|Overview}}<br />
{{Article summary text|{{Boot process overview}}}}<br />
{{Article summary heading|Related}}<br />
{{Article summary wiki|Burg}} - Burg is a brand-new boot loader based on GRUB2. It uses a new object format which allows it to be built in a wider range of OS, including Linux/Windows/OSX/Solaris/FreeBSD, etc. It also has a highly configurable menu system which works in both text and graphic mode. <br />
{{Article summary heading|Resources}}<br />
{{Article summary link|GNU GRUB -- GNU Project|http://www.gnu.org/software/grub/}}<br />
{{Article summary end}}<br />
<br />
[http://www.gnu.org/software/grub/ GRUB2] is the next generation of the GRand Unified Bootloader (GRUB). GRUB2 is derived from [http://www.nongnu.org/pupa/ PUPA] which was a research project to investigate the next generation of GRUB. GRUB2 has been rewritten from scratch to clean up everything and provide modularity and portability [http://www.gnu.org/software/grub/grub-faq.en.html#q1].<br />
<br />
In brief, the ''bootloader'' is the first software program that runs when a computer starts. It is responsible for loading and transferring control to the Linux kernel. The kernel, in turn, initializes the rest of the operating system.<br />
<br />
{{Note|From 1.99-6 onwards, GRUB2 supports Btrfs as root (without a separate {{ic|/boot}} filesystem) compressed with either zlib or LZO.}}<br />
<br />
{{Note|[[Archboot]] iso is required for {{Pkg|grub2-bios}} and {{Pkg|grub2-efi-x86_64}} installation. The official installer AIF (Arch Installation Framework) based [[Archiso]] does not support it.}}<br />
<br />
== Preface ==<br />
<br />
Although, [[GRUB]] (i.e. version 0.9x) is the standard bootloader of Arch Linux, it is considered 'legacy' by upstream. It is being replaced by GRUB2 and [[Syslinux]] in many distributions. Upstream recommends GRUB2 >=1.99 over GRUB Legacy, even for current GRUB Legacy users.<br />
<br />
=== Notes for current GRUB Legacy users ===<br />
<br />
* There are differences in the commands of GRUB and GRUB2. Familiarize yourself with [http://www.gnu.org/software/grub/manual/grub.html#Commands GRUB2 commands] before proceeding (e.g. "find" has been replaced with "search").<br />
<br />
* GRUB2 is now ''modular'' and no longer requires "stage 1.5". As a result, the bootloader itself is limited -- modules are loaded from the hard drive as needed to expand functionality (e.g. for [[LVM]] or RAID support).<br />
<br />
* Device naming has changed between GRUB and GRUB2. Partitions are numbered from 1 instead of 0 while drives are still numbered from 0, and prefixed with partition-table type. For example, {{ic|/dev/sda1}} would be referred to as {{ic|(hd0,msdos1)}} (for MBR) or {{ic|(hd0,gpt1)}} (for GPT) using GRUB2.<br />
<br />
=== Preliminary Requirements for GRUB2 ===<br />
<br />
==== BIOS systems ====<br />
<br />
===== [[GPT]] specific instructions =====<br />
<br />
GRUB2 in BIOS-GPT configuration requires a BIOS Boot Partition to embed its {{ic|core.img}} in the absence of post-MBR gap in GPT partitioned systems (which is taken over by the GPT Primary Header and Primary Partition table). This partition is used by GRUB2 only in BIOS-GPT setups. No such partition type exists in case of MBR partitioning (at least not for GRUB2). This partition is also not required if the system is UEFI based, as no embedding of bootsectors takes place in that case. Syslinux does not require this partition.<br />
<br />
For a BIOS-GPT configuration, create a 2 MiB partition using cgdisk or GNU Parted with no filesystem. The location of the partition in the partition table does not matter but it should be within the first 2 TiB region of the disk. It is advisable to put it somewhere in the beginning of the disk before the /boot partition. Set the partition type to "EF02" in cgdisk or {{ic|set <BOOT_PART_NUM> bios_grub on}} in GNU Parted.<br />
<br />
{{Note|This partition should be created before {{ic|grub-install}} or {{ic|grub-setup}} is run or before the '''Install Bootloader''' step of the Archlinux installer (if GRUB2 BIOS is selected as bootloader).}}<br />
<br />
===== [[MBR]] aka msdos partitioning specific instructions =====<br />
<br />
Usually the post-MBR gap (after the 512 byte MBR region and before the start of the 1st partition) in many MBR (or msdos disklabel) partitioned systems is 32 KiB when DOS compatibility cylinder alignment issues are satisfied in the partition table. However a post-MBR gap of about 1 to 2 MiB is recommended to provide sufficient room for embedding GRUB2's {{ic|core.img}} ([https://bugs.archlinux.org/task/24103]). It is advisable to use a partitioner which supports 1 MiB partition alignment to obtain this space as well as satisfy other non-512 byte sector issues (which are unrelated to embedding of {{ic|core.img}}).<br />
<br />
If you do not dual-boot with MS Windows (any version) in BIOS systems, it is advisable to switch to GPT partitioning - [[GUID_Partition_Table#Convert_from_MBR_to_GPT_without_data_loss]]<br />
<br />
{{Note|Create the 2MiB partition mentioned above BEFORE you convert to GPT. If you do not, gparted will not resize your boot partition to allow its creation, and when you reboot GRUB2 will not know where to look.}}<br />
<br />
==== UEFI systems ====<br />
<br />
===== Create and Mount the UEFI SYSTEM PARTITION =====<br />
<br />
Follow [[Unified_Extensible_Firmware_Interface#Create_an_UEFI_System_Partition_in_Linux]] for instructions on creating a UEFI SYSTEM PARTITION. Then mount the UEFI SYSTEM PARTITION at {{ic|/boot/efi}}. If you have mounted the UEFISYS partition in some other mountpoint, replace {{ic|/boot/efi}} in the below instructions with that mountpoint:<br />
<br />
# mkdir -p /boot/efi<br />
# mount -t vfat <UEFISYS_PART_DEVICE> /boot/efi<br />
<br />
Create a <UEFI_SYSTEM_PARTITION>{{ic|/efi}} directory, if it does not exist:<br />
<br />
# mkdir -p /boot/efi/efi<br />
<br />
== Installation ==<br />
<br />
=== During Arch Linux installation ===<br />
<br />
* Skip the '''Install Bootloader''' step and exit the installer.<br />
* Configure the network:<br />
# aif -p partial-configure-network<br />
This will bring up a prompt; put in the network interface to use, (e.g., {{ic|eth0}}) and use DHCP for easy configuration.<br />
* If you did not configure the installed system's {{ic|/etc/resolv.conf}} file during installation (for instance, if you plan to let DHCP generate it later), you will need to copy the one generated by AIF when it configured the network:<br />
# cp /etc/resolv.conf /mnt/etc/resolv.conf<br />
* If you run into network issues in the pacman update step below, you may have needed to install the {{Pkg|net-tools}} package.<br />
* Check and see if the {{ic|dm_mod}} module is loaded. If it is not, load it manually (you might need {{Pkg|grub2-bios}}):<br />
# lsmod | grep dm_mod<br />
# modprobe dm-mod<br />
{{Note|This is necessary at this point, and cannot be postponed after the chroot. If you try to use modprobe in a chroot environment that has a later kernel version from that of the installing device (at the time of writing, 2.6.33), modprobe will fail. This happens routinely using the Arch "net" installations.}}<br />
* From the installer's live shell, chroot to the installed system:<br />
# mount -o bind /dev /mnt/dev<br />
# mount -t proc /proc /mnt/proc/<br />
# mount -t sysfs /sys /mnt/sys/<br />
# chroot /mnt bash<br />
* Update pacman's database:<br />
# pacman-db-upgrade<br />
* Refresh the package list (with an extra {{ic|-y}} flag to force a refresh of all package lists even if they appear to be up to date):<br />
# pacman -Syy<br />
* Install the GRUB2 package as mentioned in the section [[#From a running Arch Linux]] (Note that the {{ic|dm-mod}} module has already been loaded, no need to do that again).<br />
<br />
=== From a running Arch Linux ===<br />
<br />
==== BIOS systems ====<br />
<br />
===== Backup Important Data =====<br />
<br />
Though a GRUB2 installation should run smoothly, it is strongly recommended to make a backup before installing {{Pkg|grub2-bios}}.<br />
<br />
* copy GRUB modules and configuration:<br />
<br />
# cp -a /boot/grub /path/to/backup/<br />
<br />
* backup the MBR and GRUB Legacy stage 1.5:<br />
<br />
# dd if=/dev/sdX of=/path/to/backup/first-sectors bs=512 count=63<br />
<br />
Replace {{ic|/dev/sd'''X'''}} with your actual disk path.<br />
<br />
{{Note|This command backs up the partition table too. Be careful while restoring if you've changed your partition setup in the meantime}}<br />
<br />
To backup only the MBR boot code use:<br />
<br />
# dd if=/dev/sdX of=/path/to/backup/mbr-boot-code bs=440 count=1<br />
<br />
You may now lightly remove {{ic|/boot/grub/}} with:<br />
<br />
# rm -rf /boot/grub<br />
<br />
and follow the instructions below. You know that if things get nasty, you could reboot your system thanks to an installation media and:<br />
<br />
* move old GRUB Legacy or GRUB2 files out of the way:<br />
<br />
# mv /boot/grub /boot/grub.nonfunctional<br />
<br />
* copy GRUB Legacy back to {{ic|/boot}}:<br />
<br />
# cp -a /path/to/backup/grub /boot/<br />
<br />
* replace MBR and next 62 sectors of sda with backed up copy (DANGEROUS!):<br />
<br />
# dd if=/path/to/backup/first-sectors of=/dev/sdX bs=512 count=63<br />
<br />
{{Note|This command also restores the partition table so be careful.}}<br />
<br />
To restore only the MBR boot code use:<br />
<br />
# dd if=/path/to/backup/mbr-boot-code of=/dev/sdX bs=440 count=1<br />
<br />
===== Install grub2-bios package =====<br />
<br />
The GRUB2 package can be installed with pacman (and will replace {{Pkg|grub}}, if it is installed):<br />
<br />
# pacman -S grub2-bios<br />
<br />
{{Note|Simply installing the package won't update the {{ic|/boot/grub/i386-pc/core.img}} file and the GRUB2 modules in {{ic|/boot/grub/i386-pc}}. You need to update them manually using {{ic|grub-install}} as explained below.}}<br />
<br />
Also load the device-mapper kernel module without which {{ic|grub-probe}} does not reliably detect disks and partitions:<br />
<br />
# modprobe dm-mod<br />
<br />
===== Install grub2-bios boot files =====<br />
<br />
There are 3 ways to install GRUB2 boot files in BIOS booting:<br />
*[[#Install_to_440-byte_MBR_boot_code_region]] (recommended) , <br />
*[[#Install_to_Partition_or_Partitionless_Disk]] (not recommended),<br />
*[[#Generate_core.img_alone]] (safest method, but requires another BIOS bootloader like [[grub-legacy]] or [[syslinux]] to be installed to chainload {{ic|/boot/grub/i386-pc/core.img}}). <br />
<br />
====== Install to 440-byte MBR boot code region ======<br />
<br />
To setup {{ic|grub2-bios}} in the 440-byte Master Boot Record boot code region, populate the {{ic|/boot/grub}} directory, generate the {{ic|/boot/grub/i386-pc/core.img}} file, and embed it in the 32 KiB (minimum size - varies depending on partition alignment) post-MBR gap (MBR disks) or in BIOS Boot Partition (GPT disks), run:<br />
<br />
# grub-install --directory=/usr/lib/grub/i386-pc --target=i386-pc --boot-directory=/boot --recheck --debug /dev/sda<br />
<br />
where {{ic|/dev/sda}} is the destination of the installation (in this case the MBR of the first SATA disk). If you use [[LVM]] for your {{ic|/boot}}, you can install GRUB2 on multiple physical disks. <br />
<br />
The {{ic|--no-floppy}} tells {{ic|grub2-bios}} utilities not to search for any floppy devices which reduces the overall execution time of {{ic|grub-install}} on many systems (it will also prevent the issue below from occurring). Otherwise you get an error that looks like this:<br />
<br />
grub-probe: error: Cannot get the real path of '/dev/fd0'<br />
Auto-detection of a filesystem module failed.<br />
Please specify the module with the option '--modules' explicitly.<br />
<br />
{{Note|{{ic|--no-floppy}} has been removed from {{ic|grub-install}} in 2.00~beta2 upstream release, and replaced with {{ic|--allow-floppy}}.}}<br />
<br />
{{Warning|Make sure to check the {{ic|/boot}} directory if you use the latter. Sometimes the {{ic| boot-directory}} parameter creates another {{ic|/boot}} folder inside of {{ic|/boot}}. A wrong install would look like: {{ic|/boot/boot/grub/}}.}}<br />
<br />
====== Install to Partition or Partitionless Disk ======<br />
<br />
{{Note|{{ic|grub2-bios}} (any version - including upstream Bazaar repo) does not encourage installation to a partition boot sector or a partitionless disk like GRUB Legacy or syslinux does. This kind of setup is prone to breakage, especially during updates, and is not supported by Arch devs.}}<br />
<br />
To set up {{ic|grub2-bios}} to a partition boot sector, to a partitionless disk (also called superfloppy) or to a floppy disk, run (using for example {{ic|/dev/sda1}} as the {{ic|/boot}} partition):<br />
<br />
# chattr -i /boot/grub/i386-pc/core.img<br />
# grub-install --directory=/usr/lib/grub/i386-pc --target=i386-pc --boot-directory=/boot --recheck --force --debug /dev/sda1<br />
# chattr +i /boot/grub/i386-pc/core.img<br />
<br />
You need to use the {{ic|--force}} option to allow usage of blocklists and should not use {{ic|1=--grub-setup=/bin/true}} (which is similar to simply generating {{ic|core.img}}).<br />
<br />
{{ic|grub-install}} will give out warnings like which should give you the idea of what might go wrong with this approach:<br />
<br />
/sbin/grub-setup: warn: Attempting to install GRUB to a partitionless disk or to a partition. This is a BAD idea.<br />
/sbin/grub-setup: warn: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. <br />
However, blocklists are UNRELIABLE and their use is discouraged.<br />
<br />
Without {{ic|--force}} you may get the below error and {{ic|grub-setup}} will not setup its boot code in the partition boot sector:<br />
<br />
/sbin/grub-setup: error: will not proceed with blocklists<br />
<br />
With {{ic|--force}} you should get:<br />
<br />
Installation finished. No error reported.<br />
<br />
The reason why {{ic|grub-setup}} does not by default allow this is because in case of partition or a partitionless disk is that {{ic|grub2-bios}} relies on embedded blocklists in the partition bootsector to locate the {{ic|/boot/grub/i386-pc/core.img}} file and the prefix dir {{ic|/boot/grub}}. The sector locations of {{ic|core.img}} may change whenever the filesystem in the partition is being altered (files copied, deleted etc.). For more info see https://bugzilla.redhat.com/show_bug.cgi?id=728742 and https://bugzilla.redhat.com/show_bug.cgi?id=730915.<br />
<br />
The workaround for this is to set the immutable flag on {{ic|/boot/grub/i386-pc/core.img}} (using chattr command as mentioned above) so that the sector locations of the {{ic|core.img}} file in the disk is not altered. The immutable flag on {{ic|/boot/grub/i386-pc/core.img}} needs to be set only if {{ic|grub2-bios}} is installed to a partition boot sector or a partitionless disk, not in case of installtion to MBR or simple generation of {{ic|core.img}} without embedding any bootsector (mentioned above).<br />
<br />
====== Generate core.img alone ======<br />
<br />
To populate the {{ic|/boot/grub}} directory and generate a {{ic|/boot/grub/i386-pc/core.img}} file '''without''' embedding any {{ic|grub2-bios}} bootsector code in the MBR, post-MBR region, or the partition bootsector, add {{ic|1=--grub-setup=/bin/true}} to {{ic|grub-install}}:<br />
<br />
# grub-install --directory=/usr/lib/grub/i386-pc --target=i386-pc --grub-setup=/bin/true --boot-directory=/boot --recheck --debug /dev/sda<br />
<br />
You can then chainload GRUB2's {{ic|core.img}} from GRUB Legacy or syslinux as a Linux kernel or a multiboot kernel.<br />
<br />
===== Generate GRUB2 BIOS Config file =====<br />
<br />
Finally, generate a configuration for GRUB2 (this is explained in greater detail in the Configuration section):<br />
<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
{{Note|The file path is {{ic|/boot/grub/grub.cfg}}, NOT {{ic|/boot/grub/i386-pc/grub.cfg}}.}}<br />
<br />
If grub2 complains about "no suitable mode found" while booting, go to [[#Correct_GRUB2_No_Suitable_Mode_Found_Error]].<br />
<br />
If {{ic|grub-mkconfig}} fails, convert your {{ic|/boot/grub/menu.lst}} file to {{ic|/boot/grub/grub.cfg}} using:<br />
<br />
# grub-menulst2cfg /boot/grub/menu.lst /boot/grub/grub.cfg<br />
<br />
For example:<br />
<br />
{{hc|/boot/grub/menu.lst|<nowiki><br />
default=0<br />
timeout=5<br />
<br />
title Arch Linux Stock Kernel<br />
root (hd0,0)<br />
kernel /vmlinuz-linux root=/dev/sda2 ro<br />
initrd /initramfs-linux.img<br />
<br />
title Arch Linux Stock Kernel Fallback<br />
root (hd0,0)<br />
kernel /vmlinuz-linux root=/dev/sda2 ro<br />
initrd /initramfs-linux-fallback.img<br />
</nowiki>}}<br />
<br />
{{hc|/boot/grub/grub.cfg|<nowiki><br />
set default='0'; if [ x"$default" = xsaved ]; then load_env; set default="$saved_entry"; fi<br />
set timeout=5<br />
<br />
menuentry 'Arch Linux Stock Kernel' {<br />
set root='(hd0,1)'; set legacy_hdbias='0'<br />
legacy_kernel '/vmlinuz-linux' '/vmlinuz-linux' 'root=/dev/sda2' 'ro'<br />
legacy_initrd '/initramfs-linux.img' '/initramfs-linux.img'<br />
<br />
}<br />
<br />
menuentry 'Arch Linux Stock Kernel Fallback' {<br />
set root='(hd0,1)'; set legacy_hdbias='0'<br />
legacy_kernel '/vmlinuz-linux' '/vmlinuz-linux' 'root=/dev/sda2' 'ro'<br />
legacy_initrd '/initramfs-linux-fallback.img' '/initramfs-linux-fallback.img'<br />
}<br />
</nowiki>}}<br />
<br />
If you forgot to create a GRUB2 {{ic|/boot/grub/grub.cfg}} config file and simply rebooted into GRUB2 Command Shell, type:<br />
<br />
sh:grub> insmod legacycfg<br />
sh:grub> legacy_configfile ${prefix}/menu.lst<br />
<br />
Boot into Arch and re-create the proper GRUB2 {{ic|/boot/grub/grub.cfg}} config file.<br />
<br />
{{Note|This option works only in BIOS systems, not in UEFI systems.}}<br />
<br />
===== Multiboot in BIOS =====<br />
<br />
====== Boot Microsoft Windows installed in BIOS-MBR mode ======<br />
<br />
{{Note|GRUB2 supports booting {{ic|bootmgr}} directly and chainload of partition boot sector is no longer required to boot Windows in a BIOS-MBR setup.}}<br />
<br />
Find the UUID of the NTFS filesystem of the Windows's SYSTEM PARTITION where the {{ic|bootmgr}} and its files reside. For example, if Windows {{ic|bootmgr}} exists at {{ic|/media/Windows/bootmgr}}:<br />
<br />
# grub-probe --target=fs_uuid /media/Windows/bootmgr<br />
69B235F6749E84CE<br />
<br />
Then, add the below code to {{ic|/etc/grub.d/40_custom}} and regenerate {{ic|grub.cfg}} with {{ic|grub-mkconfig}} as explained above to chainload Windows (Vista, 7 or 8) installed in BIOS-MBR mode:<br />
<br />
menuentry "Microsoft Windows 7 BIOS-MBR" {<br />
insmod part_msdos<br />
insmod ntfs<br />
insmod search_fs_uuid<br />
insmod ntldr <br />
search --fs-uuid --no-floppy --set=root 69B235F6749E84CE<br />
ntldr /bootmgr<br />
}<br />
<br />
For Windows XP:<br />
<br />
menuentry "Microsoft Windows XP" {<br />
insmod part_msdos<br />
insmod ntfs<br />
insmod search_fs_uuid<br />
insmod ntldr <br />
search --fs-uuid --no-floppy --set=root 69B235F6749E84CE<br />
ntldr /ntldr<br />
}<br />
<br />
==== [[UEFI]] systems ====<br />
<br />
===== Install grub2-uefi package =====<br />
<br />
{{Note|Unless specified as EFI 1.x , EFI and UEFI terms are used interchangeably to denote UEFI 2.x firmware. Also unless stated explicitely, the instructions are general and not Mac specific. Some of them may not work or may be different in Macs. Apple's EFI implementation is neither a EFI 1.x version nor UEFI 2.x version but mixes up both. This kind of firmware does not fall under any one UEFI Specification version and is therefore not a standard UEFI firmware.}}<br />
<br />
GRUB2 UEFI bootloader is available in Arch Linux only from version 1.99~rc1. To install, first [https://wiki.archlinux.org/index.php/Unified_Extensible_Firmware_Interface#Detecting_UEFI_Firmware_Arch Detect which UEFI firmware arch] you have (either x86_64 or i386).<br />
<br />
Depending on that, install the appropriate package<br />
<br />
For 64-bit aka x86_64 UEFI firmware:<br />
# pacman -S grub2-efi-x86_64<br />
<br />
For 32-bit aka i386 UEFI firmware:<br />
# pacman -S grub2-efi-i386<br />
<br />
{{Note|Simply installing the package won't update the {{ic|grub.efi}} file and the GRUB2 modules in the UEFI System Partition. You need to do this manually using {{ic|grub-install}} as explained below.}}<br />
<br />
Also load the device-mapper kernel module without which {{ic|grub-probe}} does not reliably detect disks and partitions:<br />
<br />
# modprobe dm-mod<br />
<br />
===== Install grub2-uefi boot files =====<br />
<br />
====== Install to UEFI SYSTEM PARTITION ======<br />
<br />
{{Note|The below commands assume you are using {{ic|grub2-efi-x86_64}} (for {{ic|grub2-efi-i386}} replace {{ic|x86_64}} with {{ic|i386}} in the below commands).}}<br />
<br />
The UEFI system partition will need to be mounted at {{ic|/boot/efi/}} for the GRUB2 install script to detect it:<br />
<br />
# mkdir -p /boot/efi<br />
# mount -t vfat /dev/sdXY /boot/efi<br />
<br />
Install GRUB UEFI application to {{ic|/boot/efi/efi/arch_grub}} and its modules to {{ic|/boot/grub/x86_64-efi}} (recommended) using:<br />
<br />
# grub-install --directory=/usr/lib/grub/x86_64-efi --target=x86_64-efi --root-directory=/boot/efi\ <br />
--boot-directory=/boot --bootloader-id=arch_grub --recheck --debug<br />
<br />
If you want to install grub2 modules and {{ic|grub.cfg}} at the directory {{ic|/boot/efi/efi/grub}} and the {{ic|grubx64.efi}} application at {{ic|/boot/efi/efi/arch_grub}} use:<br />
<br />
# grub-install --directory=/usr/lib/grub/x86_64-efi --target=x86_64-efi --root-directory=/boot/efi\ <br />
--boot-directory=/boot/efi/efi --bootloader-id=arch_grub --recheck --debug<br />
<br />
In this case {{ic|grub2-efi-x86_64}} will be installed into {{ic|/boot/grub}}, making the behavior consistent with the BIOS verion of GRUB2, but this is not recommended if you use both {{ic|grub2-bios}} and {{ic|grub2-efi-x86_64}} in your system, as this will overwrite {{ic|grub2-bios }}modules in {{ic|/boot/grub}}.<br />
<br />
The {{ic|--root-directory}} option mentions the mountpoint of UEFI SYSTEM PARTITION , {{ic|--bootloader-id}} mentions the name of the directory used to store the {{ic|grubx64.efi}} file and {{ic|--boot-directory}} mentions the directory wherein the actual modules will be installed (and into which {{ic|grub.cfg}} should be created).<br />
<br />
The actual paths are:<br />
<br />
<root-directory>/<efi or EFI>/<bootloader-id>/grubx64.efi<br />
<br />
<boot-directory>/grub/x86_64-efi/<all modules, grub.efi, core.efi, grub.cfg><br />
<br />
{{Note|the {{ic|--bootloader-id}} option does not change {{ic|<boot-directory>/grub}}, i.e. you cannot install the modules to {{ic|<boot-directory>/<bootloader-id>}}, the path is hard-coded to {{ic|<boot-directory>/grub}}.}}<br />
<br />
In {{ic|<nowiki>--root-directory=/boot/efi --boot-directory=/boot/efi/efi --bootloader-id=grub</nowiki>}}:<br />
<br />
<root-directory>/<efi or EFI>/<bootloader-id> == <boot-directory>/grub == /boot/efi/efi/grub<br />
<br />
In {{ic|<nowiki>--root-directory=/boot/efi --boot-directory=/boot/efi/efi --bootloader-id=arch_grub</nowiki>}}:<br />
<br />
<root-directory>/<efi or EFI>/<bootloader-id> == /boot/efi/efi/arch_grub<br />
<boot-directory>/grub == /boot/efi/efi/grub<br />
<br />
In {{ic|<nowiki>--root-directory=/boot/efi --boot-directory=/boot --bootloader-id=arch_grub</nowiki>}}:<br />
<br />
<root-directory>/<efi or EFI>/<bootloader-id> == /boot/efi/efi/arch_grub<br />
<boot-directory>/grub == /boot/grub<br />
<br />
In {{ic|<nowiki>--root-directory=/boot/efi --boot-directory=/boot --bootloader-id=grub</nowiki>}}:<br />
<br />
<root-directory>/<efi or EFI>/<bootloader-id> == /boot/efi/efi/grub<br />
<boot-directory>/grub == /boot/grub<br />
<br />
The {{ic|<nowiki><root-directory>/<efi or EFI>/<bootloader-id>/grubx64.efi</nowiki>}} is an exact copy of {{ic|<nowiki><boot-directory>/grub/x86_64-efi/core.efi</nowiki>}}.<br />
<br />
{{Note|This behavior of {{ic|--root-directory}}, {{ic|--boot-directory}}, and {{ic|--bootloader-id}} options are specific to UEFI systems and does not occur is BIOS mode. In {{ic|grub-install}}, {{ic|--root-directory}} is deprecated and {{ic|--bootloader-id}} does not exist.}}<br />
<br />
In all the cases the UEFI SYSTEM PARTITION should be mounted for {{ic|grub-install}} to install {{ic|grubx64.efi}} in it, which will be launched by the firmware (using the {{ic|efibootmgr}} created boot entry in non-Mac systems).<br />
<br />
If you notice carefully, there is no <device_path> option (Eg: {{ic|/dev/sda}}) at the end of the {{ic|grub-install}} command unlike the case of setting up GRUB2 for BIOS systems. Any <device_path> provided will be ignored by the install script as UEFI bootloaders do not use MBR or Partition boot sectors at all.<br />
<br />
You may now be able to UEFI boot your system by creating a {{ic|grub.cfg}} file by following [[#Generate_GRUB2_UEFI_Config_file]] and [[#Create_GRUB2_entry_in_the_Firmware_Boot_Manager]].<br />
<br />
===== Create GRUB2 entry in the Firmware Boot Manager =====<br />
<br />
====== Non-Mac UEFI systems ======<br />
<br />
{{ic|grub-install}} will ensure that {{ic|/boot/efi/efi/arch_grub/grubx64.efi}} is launched by default if it detects {{ic|efibootmgr}} and if it is able to access UEFI Runtime Services. Follow [[Unified_Extensible_Firmware_Interface#efibootmgr]] for more info.<br />
<br />
If you have problems running GRUB2 in UEFI mode you can try the following (worked on an ASUS Z68 mainboard):<br />
<br />
# cp /boot/efi/efi/arch_grub/grubx64.efi /boot/efi/shellx64.efi<br />
<br />
or<br />
<br />
# cp /boot/efi/efi/arch_grub/grubx64.efi /boot/efi/efi/shellx64.efi<br />
<br />
or<br />
<br />
# cp /boot/efi/efi/arch_grub/grubx64.efi /boot/efi/efi/shell/shellx64.efi<br />
<br />
After this launch the UEFI Shell from the UEFI setup/menu (in ASUS UEFI BIOS, switch to advanced mode, press Exit in the top right corner and choose "Launch EFI shell from filesystem device"). The GRUB2 menu will show up and you can boot into your system. Afterwards you can use efibootmgr to setup a menu entry (see above).<br />
<br />
====== Apple Mac EFI systems ======<br />
<br />
{{Note|TODO: GRUB upstream Bazaar mactel branch http://bzr.savannah.gnu.org/lh/grub/branches/mactel/changes . No further update from grub developers.}}<br />
{{Note|TODO: Experimental "bless" utility for Linux by Fedora developers - {{AUR|mactel-boot}}. Requires more testing.)}}<br />
<br />
Use bless command from within Mac OS X to set {{ic|grubx64.efi}} as the default boot option. You can also boot from the Mac OS X install disc and launch a Terminal there if you only have Linux installed. In the Terminal, create a directory and mount the EFI System Partition:<br />
<br />
# cd /Volumes<br />
# mkdir efi<br />
# mount -t msdos /dev/disk0s1 /Volumes/efi<br />
<br />
Then run bless on {{ic|grub.efi}} and on the EFI partition to set them as the default boot options.<br />
<br />
# bless --folder=/Volumes/efi --file=/Volumes/efi/efi/arch_grub/grubx64.efi --setBoot<br />
# bless --mount=/Volumes/efi --file=/Volumes/efi/efi/arch_grub/grubx64.efi --setBoot<br />
<br />
More info at https://help.ubuntu.com/community/UEFIBooting#Apple_Mac_EFI_systems_.28both_EFI_architecture.29.<br />
<br />
===== Generate GRUB2 UEFI Config file =====<br />
<br />
Finally, generate a configuration for GRUB2 (this is explained in greater detail in the Configuration section):<br />
<br />
# grub-mkconfig -o <boot-directory>/grub/grub.cfg<br />
<br />
{{Note|The file path is {{ic|<boot-directory>/grub/grub.cfg}}, NOT {{ic|<boot-directory>/grub/x86_64-efi/grub.cfg}}.}}<br />
<br />
If you used {{ic|<nowiki>--boot-directory=/boot</nowiki>}}:<br />
<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
If you used {{ic|<nowiki>--boot-directory=/boot/efi/efi</nowiki>}}:<br />
<br />
# grub-mkconfig -o /boot/efi/efi/grub/grub.cfg<br />
<br />
This is independent of the value of {{ic|--bootloader-id}} option.<br />
<br />
If GRUB2 complains about "no suitable mode found" while booting, try [[#Correct_GRUB2_No_Suitable_Mode_Found_Error]].<br />
<br />
===== Create GRUB2 Standalone UEFI Application =====<br />
<br />
It is possible to create a {{ic|grubx64_standalone.efi}} application which has all the modules embeddded in a memdisk within the uefi application, thus removing the need for having a separate directory populated with all the GRUB2 uefi modules and other related files. This is done using the {{ic|grub-mkstandalone}} command which is included in {{Pkg|grub2-common}} >= 1:1.99-6 package.<br />
<br />
The easiest way to do this would be with the install command already mentioned before, but specifying the modules to include. For example:<br />
<br />
# grub-mkstandalone --directory="/usr/lib/grub/x86_64-efi/" --format="x86_64-efi" --compression="xz" \<br />
--output="/boot/efi/efi/arch_grub/grubx64_standalone.efi" <any extra files you want to include><br />
<br />
The {{ic|grubx64_standalone.efi}} file expects {{ic|grub.cfg}} to be within its $prefix which is {{ic|(memdisk)/boot/grub}}. The memdisk is embedded within the efi app. The {{ic|grub-mkstandlone}} script allow passing files to be included in the memdisk image to be as the arguments to the script (in <any extra files you want to include>).<br />
<br />
If you have the {{ic|grub.cfg}} at {{ic|/home/user/Desktop/grub.cfg}}, then create a temporary {{ic|/home/user/Desktop/boot/grub/}} directory, copy the {{ic|/home/user/Desktop/grub.cfg}} to {{ic|/home/user/Desktop/boot/grub/grub.cfg}}, cd into {{ic|/home/user/Desktop/boot/grub/}} and run:<br />
<br />
# grub-mkstandalone --directory="/usr/lib/grub/x86_64-efi/" --format="x86_64-efi" --compression="xz" \<br />
--output="/boot/efi/efi/arch_grub/grubx64_standalone.efi" "boot/grub/grub.cfg"<br />
<br />
The reason to cd into {{ic|/home/user/Desktop/boot/grub/}} and to pass the file path as {{ic|boot/grub/grub.cfg}} (notice the lack of a leading slash - boot/ vs /boot/ ) is because {{ic|dir1/dir2/file}} is included as {{ic|(memdisk)/dir1/dir2/file}} by the {{ic|grub-mkstandalone}} script. <br />
<br />
If you pass {{ic|/home/user/Desktop/grub.cfg}} the file will be included as {{ic|(memdisk)/home/user/Desktop/grub.cfg}}. If you pass {{ic|/home/user/Desktop/boot/grub/grub.cfg}} the file will be included as {{ic|(memdisk)/home/user/Desktop/boot/grub/grub.cfg}}. That is the reason for cd'ing into {{ic|/home/user/Desktop/boot/grub/}} and passing {{ic|boot/grub/grub.cfg}}, to includ the file as {{ic|(memdisk)/boot/grub/grub.cfg}}, which is what {{ic|grub.efi}} expects the file to be.<br />
<br />
You need to create an UEFI Boot Manager entry for {{ic|/boot/efi/efi/arch_grub/grubx64_standalone.efi}} using {{ic|efibootmgr}}. Follow [[#Create GRUB2 entry in the Firmware Boot Manager]].<br />
<br />
===== Multiboot in UEFI =====<br />
<br />
====== Chainload Microsoft Windows x86_64 UEFI-GPT ======<br />
<br />
Find the UUID of the FAT32 filesystem in the UEFI SYSTEM PARTITION where the Windows UEFI Bootloader files reside. For example, if Windows {{ic|bootmgfw.efi}} exists at {{ic|/boot/efi/efi/Microsoft/Boot/bootmgfw.efi}} (ignore the upper-lower case differences since that is immaterial in FAT filesystem):<br />
<br />
# grub-probe --target=fs_uuid /boot/efi/efi/Microsoft/Boot/bootmgfw.efi<br />
1ce5-7f28<br />
<br />
# grub-probe --target=hints_string /boot/efi/efi/Microsoft/Boot/bootmgfw.efi<br />
--hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1<br />
<br />
Then, add this code to {{ic|/boot/grub/grub.cfg}} OR {{ic|/boot/efi/efi/grub/grub.cfg}} to chainload Windows x86_64 (Vista SP1+, 7 or 8) installed in UEFI-GPT mode:<br />
<br />
menuentry "Microsoft Windows x86_64 UEFI-GPT" {<br />
insmod part_gpt<br />
insmod fat<br />
insmod search_fs_uuid<br />
insmod chain<br />
search --fs-uuid --no-floppy --set=root --hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1 1ce5-7f28<br />
chainloader /efi/Microsoft/Boot/bootmgfw.efi<br />
}<br />
<br />
== Configuration ==<br />
<br />
You can also choose to automatically generate or manually edit {{ic|grub.cfg}}.<br />
<br />
{{Note|If GRUB2 was installed with the {{ic|--boot-directory}} option set, the {{ic|grub.cfg}} file must be placed in the same directory as {{ic|grubx64.efi}}. Otherwise, the {{ic|grub.cfg}} file goes in {{ic|/boot/grub/}}, just like in the BIOS version of GRUB2.}}<br />
<br />
{{Note|Here is a quite complete description of how to configure GRUB2: http://members.iinet.net/~herman546/p20/GRUB2%20Configuration%20File%20Commands.html }}<br />
<br />
=== Automatically generating using grub-mkconfig (Recommended) ===<br />
<br />
The GRUB2 {{ic|menu.lst}} equivalent configuration files are {{ic|/etc/default/grub}} and {{ic|/etc/grub.d/*}}. {{ic|grub-mkconfig}} uses these files to generate {{ic|grub.cfg}}. By default the script outputs to stdout. To generate a {{ic|grub.cfg}} file run the command:<br />
<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
{{ic|/etc/grub.d/10_linux}} is set to automatically add menu items for Arch linux that work out of the box, to any generated configuration. Other operating systems may need to be added manually by editing {{ic|/etc/grub.d/40_custom}}<br />
<br />
==== Additional arguments ====<br />
<br />
To pass custom additional arguments to the linux image, you can set the {{ic|GRUB_CMDLINE_LINUX}} variable in {{ic|/etc/default/grub}}. This is analogous to adding commands to the kernel line in legacy GRUB.<br />
<br />
For example, use {{ic|<nowiki>GRUB_CMDLINE_LINUX="resume=/dev/sdaX"</nowiki>}} where {{ic|sda'''X'''}} is your swap partition to enable resume after hibernation.<br />
<br />
=== Manually creating grub.cfg ===<br />
<br />
A basic GRUB config file uses the following options<br />
* {{ic|(hdX,Y)}} is the partition {{ic|Y}} on disk {{ic|X}}, partition numbers starting at 1, disk numbers starting at 0<br />
* {{ic|1=set default=N}} is the default boot entry that is chosen after timeout for user action<br />
* {{ic|1=set timeout=M}} is the time {{ic|M}} to wait in seconds for a user selection before default is booted<br />
* {{ic|<nowiki>menuentry "title" {entry options}</nowiki>}} is a boot entry titled {{ic|title}}<br />
* {{ic|1=set root=(hdX,Y)}} sets the boot partition, where the kernel and GRUB modules are stored (boot need not be a separate partition, and may simply be a directory under the "root" partition ({{ic|/}})<br />
<br />
An example configuration:<br />
<br />
{{hc<br />
|/boot/grub/grub.cfg<br />
|<nowiki><br />
# Config file for GRUB2 - The GNU GRand Unified Bootloader<br />
# /boot/grub/grub.cfg<br />
<br />
# DEVICE NAME CONVERSIONS<br />
#<br />
# Linux Grub<br />
# -------------------------<br />
# /dev/fd0 (fd0)<br />
# /dev/sda (hd0)<br />
# /dev/sdb2 (hd1,2)<br />
# /dev/sda3 (hd0,3)<br />
#<br />
<br />
# Timeout for menu<br />
set timeout=5<br />
<br />
# Set default boot entry as Entry 0<br />
set default=0<br />
<br />
# (0) Arch Linux<br />
menuentry "Arch Linux" {<br />
set root=(hd0,1)<br />
linux /vmlinuz-linux root=/dev/sda3 ro<br />
initrd /initramfs-linux.img<br />
}<br />
<br />
## (1) Windows<br />
#menuentry "Windows" {<br />
#set root=(hd0,3)<br />
#chainloader +1<br />
#}<br />
</nowiki>}}<br />
<br />
=== Dual-booting ===<br />
<br />
{{Note|If you want GRUB2 to automatically search for other systems, you may wish to install {{Pkg|os-prober}}.}}<br />
<br />
==== Using grub-mkconfig ====<br />
The best way to add other entries is editing the {{ic|/etc/grub.d/40_custom}}. The entries in this file will be automatically added when running {{ic|grub-mkconfig}}.<br />
After adding the new lines, run:<br />
# grub-mkconfig -o /boot/grub/grub.cfg <br />
to generate an updated {{ic|grub.cfg}}.<br />
<br />
===== With GNU/Linux =====<br />
<br />
Assuming that the other distro is on partition {{ic|sda2}}:<br />
<br />
menuentry "Other Linux" {<br />
set root=(hd0,2)<br />
linux /boot/vmlinuz (add other options here as required)<br />
initrd /boot/initrd.img (if the other kernel uses/needs one)<br />
}<br />
<br />
===== With FreeBSD =====<br />
<br />
Requires that FreeBSD is installed on a single partition with UFS. Assuming it is installed on {{ic|sda4}}:<br />
<br />
menuentry "FreeBSD" {<br />
set root=(hd0,4)<br />
chainloader +1<br />
}<br />
<br />
===== With Windows =====<br />
<br />
This assumes that your Windows partition is {{ic|sda3}}.<br />
<br />
# (2) Windows XP<br />
menuentry "Windows XP" {<br />
set root=(hd0,3)<br />
chainloader (hd0,3)+1<br />
}<br />
<br />
If the Windows Bootloader is on an entirely different harddrive than GRUB, it may be necessary to trick Windows into believing that it is in fact the first harddrive. This was possible in the old GRUB with {{ic|map}} and is now done with {{ic|drivemap}}. Assume GRUB is on {{ic|hd0}} and windows on {{ic|hd2}}, you need to add the following after {{ic|set root}}:<br />
<br />
drivemap -s hd0 hd2<br />
<br />
==== With Windows via EasyBCD and NeoGRUB ====<br />
<br />
Since EasyBCD's NeoGRUB currently does not understand the GRUB2 menu format, chainload to it by replacing the contents of your {{ic|C:\NST\menu.lst}} file with lines similar to the following:<br />
<br />
default 0<br />
timeout 1<br />
<br />
title Chainload into GRUB v2<br />
root (hd0,7)<br />
kernel /boot/grub/i386-pc/core.img<br />
<br />
===Visual Configuration===<br />
<br />
In GRUB2 it is possible, by default, to change the look of the menu. Make sure to initialize, if not done already, GRUB2 graphical terminal, gfxterm, with proper video mode, gfxmode, in GRUB2. This can be seen in the section [[#Correct_GRUB2_No_Suitable_Mode_Found_Error]]. This video mode is passed by GRUB2 to the linux kernel via 'gfxpayload' so any visual configurations need this mode in order to be in effect.<br />
<br />
====Setting the framebuffer resolution ====<br />
<br />
GRUB2 can set the framebuffer for both GRUB2 itself and the kernel. The old {{ic|1=vga=}} way is deprecated. The preferred method is editing {{ic|/etc/default/grub}} as the following sample:<br />
<br />
GRUB_GFXMODE=1024x768x32<br />
GRUB_GFXPAYLOAD_LINUX=keep<br />
<br />
To generate the changes, run: <br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
The {{ic|gfxpayload}} property will make sure the kernel keeps the resolution.<br />
<br />
{{Note|If this example does not work for you try to replace {{ic|1=gfxmode="1024x768x32"}} by {{ic|1=vbemode="0x105"}}. Remember to replace the specified resolution with one suitable for your screen.}}<br />
{{Note|To show all the modes you can use {{ic|1=# hwinfo --framebuffer}} (hwinfo is available in [community]), while at GRUB2 prompt you can use the {{ic|1=vbeinfo}} command.}}<br />
<br />
If this method does not work for you, the deprecated {{ic|1=vga=}} method will still work. Just<br />
add it next to the {{ic|1="GRUB_CMDLINE_LINUX_DEFAULT="}} line in {{ic|/etc/default/grub}}<br />
for eg: {{ic|1="GRUB_CMDLINE_LINUX_DEFAULT="quiet splash vga=792"}} will give you a {{ic|1024x768}} resolution.<br />
<br />
You can choose one of these resolutions: {{ic|640×480}}, {{ic|800×600}}, {{ic|1024×768}}, {{ic|1280×1024}}, {{ic|1600×1200}}<br />
<br />
====915resolution hack ====<br />
<br />
Some times for Intel graphic adapters neither {{ic|1=# hwinfo --framebuffer}} nor {{ic|1=vbeinfo}} will show you the desired resolution. In this case you can use {{ic|915resolution}} hack. This hack will temporarily modify video BIOS and add needed resolution. See [http://915resolution.mango-lang.org/ 915resolution's home page]<br />
<br />
In the following I will proceed with the example for my system. Please adjust the recipe for your needs. First you need to find a video mode which will be modified later. For that, run {{ic|915resolution}} in GRUB2 command shell:<br />
915resolution -l<br />
The output will be something like:<br />
Intel 800/900 Series VBIOS Hack : version 0.5.3<br />
...<br />
Mode 30 : 640x480, 8 bits/pixel<br />
...<br />
Next, our purpose is to overwrite mode 30. (You can choose what ever mode you want.) In the file {{ic|/etc/grub.d/00_header}} just before the {{ic|set gfxmode&#61;${GRUB_GFXMODE}}} line insert:<br />
915resolution 30 1440 900<br />
Here we are overwriting the mode {{ic|30}} with {{ic|1440x900}} resolution. Lastly we need to set {{ic|GRUB_GFXMODE}} as described earlier, regenerate GRUB2 configuration file and reboot to test changes:<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
# reboot<br />
<br />
====Background image and bitmap fonts====<br />
<br />
GRUB2 comes with support for background images and bitmap fonts in {{ic|pf2}} format. The unifont font is included in the {{Pkg|grub2-common}} package under the filename {{ic|unicode.pf2}}, or, as only ASCII characters under the name {{ic|ascii.pf2}}. <br />
<br />
Image formats supported include tga, png and jpeg, providing the correct modules are loaded. The maximum supported resolution depends on your hardware.<br />
<br />
Make sure you have set up the proper [https://wiki.archlinux.org/index.php/GRUB2#Setting_the_framebuffer_resolution framebuffer resolution].<br />
<br />
Edit {{ic|/etc/default/grub}} like this:<br />
GRUB_BACKGROUND="/boot/grub/archlinux.tga"<br />
#GRUB_THEME="/path/to/gfxtheme"<br />
<br />
({{ic|archlinux.tga}} is a placeholder; put your file name there)<br />
<br />
{{Note|If you have installed GRUB on a separate partition, {{ic|/boot/grub/archlinux.tga}} becomes {{ic|/grub/archlinux.tga}}.}}<br />
<br />
To generate the changes and add the information into {{ic|grub.cfg}}, run: <br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
If adding the splash image was successful, the user will see {{ic|"Found background image..."}} in the terminal as the command is executed. <br />
If this phrase is not seen, the image information was probably not incorporated into the {{ic|grub.cfg}} file.<br />
<br />
If the image is not displayed, check:<br />
* The path and the filename in {{ic|/etc/default/grub}} are correct.<br />
* The image is of the proper size and format (tga, png, 8-bit jpg).<br />
* The image was saved in the RGB mode, and is not indexed.<br />
* The console mode is not enabled in {{ic|/etc/default/grub}}.<br />
* The command {{ic|grub-mkconfig}} must be executed to place the background image information into the {{ic|/boot/grub/grub.cfg}} file.<br />
<br />
====Theme====<br />
<br />
Here is an example for configuring Starfield theme which was included in GRUB2 package.<br />
<br />
Edit {{ic|/etc/default/grub}}<br />
GRUB_THEME="/boot/grub/themes/starfield/theme.txt"<br />
<br />
Generate the changes:<br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
If configuring the theme was successful, you'll see {{ic|Found theme: /boot/grub/themes/starfield/theme.txt}} in the terminal.<br />
<br />
====Menu colors====<br />
<br />
As in GRUB Legacy (0.9x), you can change the menu colors in GRUB2. The available colors for GRUB2 are at http://www.gnu.org/software/grub/manual/html_node/Theme-file-format.html#Theme-file-format.<br />
Here is an example:<br />
<br />
Edit {{ic|/etc/default/grub}}:<br />
GRUB_COLOR_NORMAL="light-blue/black"<br />
GRUB_COLOR_HIGHLIGHT="light-cyan/blue"<br />
<br />
Generate the changes:<br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
====Hidden menu====<br />
<br />
One of the unique features of GRUB2 is hiding/skipping the menu and showing it by holding {{keypress|Shift}} when needed. You can also adjust whether you want to see the timeout counter.<br />
<br />
Edit {{ic|/etc/default/grub}} as you wish. Here is an example where the comments from the beginning of the two lines have been removed to enable the feature, the timeout has been set to five seconds and to be shown to the user:<br />
GRUB_HIDDEN_TIMEOUT=5<br />
GRUB_HIDDEN_TIMEOUT_QUIET=false<br />
<br />
and run:<br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
=== Other Options ===<br />
<br />
==== LVM ====<br />
<br />
If you use [[LVM]] for your {{ic|/boot}}, add the following before menuentry lines:<br />
<br />
insmod lvm<br />
<br />
and specify your root in the menuentry as:<br />
<br />
set root=(''lvm_group_name''-''lvm_logical_boot_partition_name'')<br />
<br />
Example:<br />
<br />
# (0) Arch Linux<br />
menuentry "Arch Linux" {<br />
insmod lvm<br />
set root=(VolumeGroup-lv_boot)<br />
# you can only set following two lines<br />
linux /vmlinuz-linux root=/dev/mapper/VolumeGroup-root ro<br />
initrd /initramfs-linux.img<br />
}<br />
<br />
==== Raid ====<br />
<br />
GRUB2 provides convenient handling of raid-volumes. You need to add:<br />
insmod raid<br />
<br />
which allows you to address the volume natively. E.g. {{ic|/dev/md0}} becomes:<br />
set root=(md0)<br />
<br />
whereas a partitioned raid-volume (e.g. {{ic|/dev/md0p1}}) becomes:<br />
set root=(md0,1)<br />
<br />
==== Persistent block device naming ====<br />
You can use UUIDs to detect partitions instead of the "old" {{ic|/dev/sd*}} and {{ic|/dev/hd*}} scheming. It has the advantage of detecting partitions by their unique UUIDs, which is needed by some people booting with complicated partition setups.<br />
<br />
UUIDs are used by default in the recent versions of GRUB2 - there is no downside in it anyway except that you need to re-generate the {{ic|grub.cfg}} file every time you resize or reformat your partitions. Remember this when modifying partitions with Live-CD.<br />
<br />
The recent versions of GRUB2 use UUIDs by default. You can re-enable the use of UUIDS by simply commenting the UUID line (this is also what it looks like by default):<br />
#GRUB_DISABLE_LINUX_UUID=true<br />
you can also just set the value as {{ic|false}} as shown here:<br />
GRUB_DISABLE_LINUX_UUID=false<br />
<br />
Either way, do not forget to generate the changes:<br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
==== Using Labels ====<br />
<br />
It is possible to use labels, human-readable strings attached to filesystems, by using the {{ic|--label}} option to {{ic|search}}. First of all, label your existing partition:<br />
# tune2fs -L a <LABEL> <PARTITION><br />
<br />
Then, add an entry using labels. An example of this:<br />
<br />
menuentry "Arch Linux, session texte" {<br />
search --label --no-floppy --set=root archroot<br />
linux /boot/vmlinuz-linux root=/dev/disk/by-label/archroot ro<br />
initrd /boot/initramfs-linux.img<br />
}<br />
<br />
==== Recall previous entry ====<br />
<br />
GRUB2 can remember the last entry you booted from and use this as the default entry to boot from next time. This is useful if you have multiple kernels (i.e., the current Arch one and the LTS kernel as a fallback option) or operating systems. To do this, edit {{ic|/etc/default/grub}} and change the setting of {{ic|GRUB_DEFAULT}}:<br />
<br />
GRUB_DEFAULT=saved<br />
<br />
This ensures that GRUB will default to the saved entry. To enable saving the selected entry, add the following line to {{ic|/etc/default/grub}}:<br />
<br />
GRUB_SAVEDEFAULT=true<br />
<br />
{{Note|Manually added menu items, eg Windows in {{ic|/etc/grub.d/40_custom}}, will need {{ic|savedefault}} added. Remember to regenerate your configuration file.}}<br />
<br />
==== Security ====<br />
<br />
If you want to secure GRUB2 so it is not possible for anyone to change boot parameters or use the command line, you can add a user/password combination to GRUB2's configuration files. To do this, run the command {{ic|grub-mkpasswd_pbkdf2}}. Enter a password and confirm it. The output will look like this:<br />
<br />
{{bc|<nowiki><br />
Your PBKDF2 is grub.pbkdf2.sha512.10000.C8ABD3E93C4DFC83138B0C7A3D719BC650E6234310DA069E6FDB0DD4156313DA3D0D9BFFC2846C21D5A2DDA515114CF6378F8A064C94198D0618E70D23717E82.509BFA8A4217EAD0B33C87432524C0B6B64B34FBAD22D3E6E6874D9B101996C5F98AB1746FE7C7199147ECF4ABD8661C222EEEDB7D14A843261FFF2C07B1269A</nowiki>}}Then, add the following to {{ic|/etc/grub.d/00_header}}:<br />
{{bc|<nowiki>cat << EOF<br />
<br />
set superusers="username"<br />
password_pbkdf2 username <password><br />
<br />
EOF</nowiki>}}<br />
where {{ic|<password>}} is the string generated by {{ic|grub-mkpasswd_pbkdf2}}.<br />
<br />
Regenerate your configuration file. Your GRUB2 command line and boot parameters are now protected.<br />
<br />
==== Root Encryption ====<br />
<br />
To let GRUB2 automatically add the kernel parameters for root encryption,<br />
add {{ic|1=cryptdevice=/dev/yourdevice:label}} to {{ic|GRUB_CMDLINE_LINUX}} in {{ic|/etc/defaults/grub}}.<br />
<br />
Example with root mapped to {{ic|/dev/mapper/root}}:<br />
<br />
GRUB_CMDLINE_LINUX="cryptdevice=/dev/sda2:root"<br />
<br />
Also, disable the usage of UUIDs for the rootfs:<br />
<br />
GRUB_DISABLE_LINUX_UUID=true<br />
<br />
Regenerate the configuration.<br />
<br />
=== Booting an ISO Directly From GRUB2 ===<br />
Edit {{ic|/etc/grub.d/40_custom}} to add an entry for the target ISO. When finished, update the GRUB menu as with the usual {{ic|grub-mkconfig -o /boot/grub/grub.cfg}} (as root).<br />
<br />
==== Arch ISO ====<br />
{{Note|Be sure to adjust the "hdX,Y" in the third line to point to the correct disk/partition number of the isofile. Also adjust the img_dev line to match this same location.}}<br />
<br />
menuentry "Archlinux-2011.08.19-netinstall-x86_64.iso" {<br />
set isofile="/archives/archlinux-2011.08.19-netinstall-x86_64.iso"<br />
loopback loop (hd0,7)$isofile<br />
linux (loop)/arch/boot/x86_64/vmlinuz archisolabel=ARCH_201108 img_dev=/dev/sda7 img_loop=$isofile earlymodules=loop<br />
initrd (loop)/arch/boot/x86_64/archiso.img<br />
}<br />
<br />
==== Ubuntu ISO ====<br />
{{Note|Be sure to adjust the "hdX,Y" in the third line to point to the correct disk/partition number of the isofile. }}<br />
<br />
menuentry "ubuntu-11.04-desktop-amd64.iso" {<br />
set isofile="/path/to/ubuntu-11.04-desktop-amd64.iso"<br />
loopback loop (hdX,Y)$isofile<br />
linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile quiet noeject noprompt splash --<br />
initrd (loop)/casper/initrd.lz<br />
}<br />
<br />
== Using the command shell ==<br />
<br />
Since the MBR is too small to store all GRUB2 modules, only the menu and a few basic commands reside there. The majority of GRUB2 functionality remains in modules in {{ic|/boot/grub}}, which are inserted as needed. In error conditions (e.g. if the partition layout changes) GRUB2 may fail to boot. When this happens, a command shell may appear.<br />
<br />
GRUB2 offers multiple shells/prompts. If there is a problem reading the menu but the bootloader is able to find the disk, you will likely be dropped to the "normal" shell:<br />
sh:grub><br />
<br />
If there is a more serious problem (e.g. GRUB cannot find required files), you may instead be dropped to the "rescue" shell:<br />
grub rescue><br />
<br />
The rescue shell is a restricted subset of the normal shell, offering much less functionality. If dumped to the rescue shell, first try inserting the "normal" module, then starting the "normal" shell:<br />
grub rescue> set prefix=(hdX,Y)/boot/grub<br />
grub rescue> insmod (hdX,Y)/boot/grub/normal.mod<br />
rescue:grub> normal<br />
<br />
=== Pager support ===<br />
<br />
GRUB2 supports pager for reading commands that provide long output (like the help command). This works only in normal shell mode and not in rescue mode. To enable pager, in GRUB2 command shell type:<br />
sh:grub> set pager=1<br />
<br />
== GUI configuration tools ==<br />
<br />
Following package may be installed from [[AUR]]<br />
* [https://aur.archlinux.org/packages.php?ID=44020 grub-customizer] (requires gettext gksu gtkmm hicolor-icon-theme openssl)<br />
*:Customize the bootloader (GRUB2 or BURG)<br />
* [http://kde-apps.org/content/show.php?content=139643 grub2-editor] (requires kdelibs)<br />
*:A KDE4 control module for configuring the GRUB2 bootloader<br />
* [http://kde-apps.org/content/show.php?content=137886 kcm-grub2] (requires kdelibs python2-qt kdebindings-python)<br />
*:This Kcm module manages the most common settings of Grub2.<br />
* [http://sourceforge.net/projects/startup-manager/ startupmanager] (requires gnome-python imagemagick yelp python2 xorg-xrandr)<br />
*:GUI app for changing the settings of GRUB, GRUB2, Usplash and Splashy<br />
<br />
== parttool or legacy hide/unhide ==<br />
<br />
If you have a win9x paradigm with hidden C disks GRUB Legacy had the hide/unhide feature. In GRUB2 this has been replaced by parttool. For example, to boot the third C disk of three win9x installations on the CLI enter the CLI and:<br />
parttool hd0,1 hidden+ boot-<br />
parttool hd0,2 hidden+ boot-<br />
parttool hd0,3 hidden- boot+<br />
set root=hd0,3<br />
chainloader +1<br />
boot<br />
<br />
== Using the rescue console ==<br />
<br />
See [[#Using the command shell]] first. If unable to activate the standard shell, one possible solution is to boot using a live CD or some other rescue disk to correct configuration errors and reinstall GRUB. However, such a boot disk is not always available (nor necessary); the rescue console is surprisingly robust.<br />
<br />
The available commands in GRUB rescue include {{ic|insmod}}, {{ic|ls}}, {{ic|set}}, and {{ic|unset}}. This example uses {{ic|set}} and {{ic|insmod}}. {{ic|set}} modifies variables and {{ic|insmod}} inserts new modules to add functionality.<br />
<br />
Before starting, the user must know the location of their {{ic|/boot}} partition (be it a separate partition, or a subdirectory under their root):<br />
grub rescue> set prefix=(hdX,Y)/boot/grub<br />
<br />
where X is the physical drive number and Y is the partition number.<br />
<br />
To expand console capabilities, insert the {{ic|linux}} module:<br />
grub rescue> insmod (hdX,Y)/boot/grub/linux.mod<br />
<br />
{{Note|With a separate boot partition, omit {{ic|/boot}} from the path, (i.e. type {{ic|1=set prefix=(hdX,Y)/grub}} and {{ic|insmod (hdX,Y)/grub/linux.mod}}).}}<br />
<br />
This introduces the {{ic|linux}} and {{ic|initrd}} commands, which should be familiar (see [[#Configuration]]).<br />
<br />
An example, booting Arch Linux:<br />
set root=(hd0,5)<br />
linux /boot/vmlinuz-linux root=/dev/sda5<br />
initrd /boot/initramfs-linux.img<br />
boot<br />
<br />
With a separate boot partition, again change the lines accordingly:<br />
set root=(hd0,5)<br />
linux /vmlinuz-linux root=/dev/sda6<br />
initrd /initramfs-linux.img<br />
boot<br />
<br />
After successfully booting the Arch Linux installation, users can correct {{ic|grub.cfg}} as needed and then reinstall GRUB2.<br />
<br />
to reinstall GRUB2 and fix the problem completely, changing {{ic|/dev/sda}} if needed. See [[#Bootloader installation]] for details.<br />
<br />
== Combining the use of UUID's and basic scripting ==<br />
<br />
If you like the idea of using UUID's to avoid unreliable BIOS mappings or are struggling with GRUB's syntax, here is an example boot menu item that uses UUID's and a small script to direct GRUB to the proper disk partitions for your system. All you need to do is replace the UUID's in the sample with the correct UUID's for your system. The example applies to a system with a boot and root partition. You will obviously need to modify the GRUB configuration if you have additional partitions:<br />
<br />
menuentry "Arch Linux 64" {<br />
# Set the UUIDs for your boot and root partition respectively<br />
set the_boot_uuid=ece0448f-bb08-486d-9864-ac3271bd8d07 <br />
set the_root_uuid=c55da16f-e2af-4603-9e0b-03f5f565ec4a<br />
<br />
# (Note: This may be the same as your boot partition)<br />
<br />
# Get the boot/root devices and set them in the root and grub_boot variables <br />
search --fs-uuid --no-floppy --set=root $the_root_uuid <br />
search --fs-uuid --no-floppy --set=grub_boot $the_boot_uuid<br />
<br />
# Check to see if boot and root are equal.<br />
# If they are, then append /boot to $grub_boot (Since $grub_boot is actually the root partition)<br />
if [ $the_boot_uuid == $the_root_uuid] ; then<br />
set grub_boot=$grub_boot/boot<br />
fi<br />
<br />
# $grub_boot now points to the correct location, so the following will properly find the kernel and initrd<br />
linux ($grub_boot)/vmlinuz-linux root=/dev/disk/by-uuid/$uuid_os_root ro<br />
initrd ($grub_boot)/initramfs-linux.img<br />
}<br />
<br />
== Troubleshooting ==<br />
<br />
Any troubleshooting should be added here.<br />
<br />
=== Enable GRUB2 debug messages ===<br />
<br />
Add:<br />
<br />
set pager=1<br />
set debug=all<br />
<br />
to {{ic|grub.cfg}}.<br />
<br />
=== Correct GRUB2 No Suitable Mode Found Error ===<br />
<br />
If you get this error when booting any menuentry:<br />
<br />
error: no suitable mode found<br />
Booting however<br />
<br />
Then you need to initialize GRUB2 graphical terminal (gfxterm) with proper video mode (gfxmode) in GRUB2. This video mode is passed by GRUB2 to the linux kernel via 'gfxpayload'. In case of UEFI systems, if the GRUB2 video mode is not initialized, no kernel boot messages will be shown in the terminal (atleast until KMS kicks in)<br />
<br />
Copy {{ic|/usr/share/grub/unicode.pf2}} to ${GRUB2_PREFIX_DIR} ({{ic|/boot/grub/}} in case of BIOS and UEFI systems. If GRUB2 UEFI was installed with {{ic|1=--boot-directory=/boot/efi/efi}} set, then the directory is {{ic|/boot/efi/efi/grub/}}:<br />
<br />
# cp /usr/share/grub/unicode.pf2 ${GRUB2_PREFIX_DIR}<br />
<br />
If {{ic|/usr/share/grub/unicode.pf2}} does not exist, install {{Pkg|bdf-unifont}}, create the {{ic|unifont.pf2}} file and then copy it to ${GRUB2_PREFIX_DIR}:<br />
<br />
# grub-mkfont -o unicode.pf2 /usr/share/fonts/misc/unifont.bdf<br />
<br />
Then, in the {{ic|grub.cfg}} file, add the following lines to enable GRUB2 to pass the video mode correctly to the kernel, without of which you will only get a black screen (no output) but booting (actually) proceeds successfully without any system hang.<br />
<br />
BIOS systems:<br />
<br />
insmod vbe<br />
<br />
UEFI systems:<br />
<br />
insmod efi_gop<br />
insmod efi_uga<br />
<br />
After that add the following code (common to both BIOS and UEFI):<br />
<br />
insmod font<br />
<br />
if loadfont ${prefix}/fonts/unicode.pf2<br />
then<br />
insmod gfxterm<br />
set gfxmode=auto<br />
set gfxpayload=keep<br />
terminal_output gfxterm<br />
fi<br />
<br />
As you can see for gfxterm (graphical terminal) to function properly, {{ic|unicode.pf2}} font file should exist in ${GRUB2_PREFIX_DIR}.<br />
<br />
=== msdos-style error message ===<br />
<br />
grub-setup: warn: This msdos-style partition label has no post-MBR gap; embedding won't be possible!<br />
grub-setup: warn: Embedding is not possible. GRUB can only be installed in this setup by using blocklists.<br />
However, blocklists are UNRELIABLE and its use is discouraged.<br />
grub-setup: error: If you really want blocklists, use --force.<br />
<br />
This error may occur when you try installing GRUB2 in a VMware container. Read more about it [http://bbs.archlinux.org/viewtopic.php?pid=581760#p581760 here]. It happens when the first partition starts just after the MBR (block 63), without the usual space of 1 MiB (2048 blocks) before the first partition. Read [[#MBR_aka_msdos_partitioning_specific_instructions]]<br />
<br />
=== UEFI GRUB2 drops to shell ===<br />
<br />
If grub loads but drop you into the rescue shell with no errors, it may be because of a missing or misplaced {{ic|grub.cfg}}. This will happen if GRUB2 UEFI was installed with {{ic|--boot-directory}} and {{ic|grub.cfg}} is missing OR if the partition number of the boot partition changed (which is hard-coded into the {{ic|grubx64.efi}} file).<br />
<br />
=== UEFI GRUB2 not loaded ===<br />
In some cases the EFI may fail to load GRUB correctly. Provided everything is set up correctly, the output of:<br />
efibootmgr -v<br />
might look something like this:<br />
BootCurrent: 0000<br />
Timeout: 3 seconds<br />
BootOrder: 0000,0001,0002<br />
Boot0000* Grub HD(1,800,32000,23532fbb-1bfa-4e46-851a-b494bfe9478c)File(\efi\grub\grub.efi)<br />
Boot0001* Shell HD(1,800,32000,23532fbb-1bfa-4e46-851a-b494bfe9478c)File(\EfiShell.efi)<br />
Boot0002* Festplatte BIOS(2,0,00)P0: SAMSUNG HD204UI<br />
If everything works correctly, the EFI would now automatically load grub.<br><br />
If the screen only goes black for a second and the next boot option is tried afterwards, according to [https://bbs.archlinux.org/viewtopic.php?pid=981560#p981560 this post], moving grub to the partition root can help. The boot option has to be deleted and recreated afterwards. The entry for grub should look like this then:<br />
Boot0000* Grub HD(1,800,32000,23532fbb-1bfa-4e46-851a-b494bfe9478c)File(\grub.efi)<br />
<br />
=== Invalid signature ===<br />
If trying to boot windows results in an "invalid signature" error, e.g. after reconfiguring partitions or adding additional hard drives, (re)move grub's device configuration and let it reconfigure:<br />
# mv /boot/grub/device.map /boot/grub/device.map-old<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
{{ic|grub-mkconfig}} should now mention all found boot options including windows. If it works, remove {{ic|/boot/grub/device.map-old}}.<br />
<br />
== References ==<br />
<br />
# Official GRUB2 Manual - http://www.gnu.org/software/grub/manual/grub.html<br />
# Ubuntu wiki page for Grub2 - https://help.ubuntu.com/community/Grub2<br />
# GRUB2 wiki page describing steps to compile for UEFI systems - https://help.ubuntu.com/community/UEFIBooting<br />
# Wikipedia's page on [http://en.wikipedia.org/wiki/BIOS_Boot_partition BIOS Boot Partition]<br />
<br />
== External Links ==<br />
<br />
# [https://github.com/the-ridikulus-rat/My_Shell_Scripts/blob/master/grub/grub_bios.sh A Linux Bash Shell script to compile and install GRUB2 for BIOS from BZR Source]<br />
# [https://github.com/the-ridikulus-rat/My_Shell_Scripts/blob/master/grub/grub_uefi.sh A Linux Bash Shell script to compile and install GRUB2 for UEFI from BZR Source]</div>SYSMANhttps://wiki.archlinux.org/index.php?title=GRUB&diff=195164GRUB2012-04-19T07:23:08Z<p>SYSMAN: In section "Install to UEFI SYSTEM PARTITION" the long command line examples for grub-install were overflowing outside the blue-background box</p>
<hr />
<div>[[Category:Boot loaders (English)]]<br />
{{i18n|GRUB2}}<br />
[[fr:GRUB2]]<br />
{{Article summary start}}<br />
{{Article summary text|Covers various aspects of the next generation of the GRand Unified Bootloader (GRUB2).}}<br />
{{Article summary heading|Overview}}<br />
{{Article summary text|{{Boot process overview}}}}<br />
{{Article summary heading|Related}}<br />
{{Article summary wiki|Burg}} - Burg is a brand-new boot loader based on GRUB2. It uses a new object format which allows it to be built in a wider range of OS, including Linux/Windows/OSX/Solaris/FreeBSD, etc. It also has a highly configurable menu system which works in both text and graphic mode. <br />
{{Article summary heading|Resources}}<br />
{{Article summary link|GNU GRUB -- GNU Project|http://www.gnu.org/software/grub/}}<br />
{{Article summary end}}<br />
<br />
[http://www.gnu.org/software/grub/ GRUB2] is the next generation of the GRand Unified Bootloader (GRUB). GRUB2 is derived from [http://www.nongnu.org/pupa/ PUPA] which was a research project to investigate the next generation of GRUB. GRUB2 has been rewritten from scratch to clean up everything and provide modularity and portability [http://www.gnu.org/software/grub/grub-faq.en.html#q1].<br />
<br />
In brief, the ''bootloader'' is the first software program that runs when a computer starts. It is responsible for loading and transferring control to the Linux kernel. The kernel, in turn, initializes the rest of the operating system.<br />
<br />
{{Note|From 1.99-6 onwards, GRUB2 supports Btrfs as root (without a separate {{ic|/boot}} filesystem) compressed with either zlib or LZO.}}<br />
<br />
{{Note|[[Archboot]] iso is required for {{Pkg|grub2-bios}} and {{Pkg|grub2-efi-x86_64}} installation. The official installer AIF (Arch Installation Framework) based [[Archiso]] does not support it.}}<br />
<br />
== Preface ==<br />
<br />
Although, [[GRUB]] (i.e. version 0.9x) is the standard bootloader of Arch Linux, it is considered 'legacy' by upstream. It is being replaced by GRUB2 and [[Syslinux]] in many distributions. Upstream recommends GRUB2 >=1.99 over GRUB Legacy, even for current GRUB Legacy users.<br />
<br />
=== Notes for current GRUB Legacy users ===<br />
<br />
* There are differences in the commands of GRUB and GRUB2. Familiarize yourself with [http://www.gnu.org/software/grub/manual/grub.html#Commands GRUB2 commands] before proceeding (e.g. "find" has been replaced with "search").<br />
<br />
* GRUB2 is now ''modular'' and no longer requires "stage 1.5". As a result, the bootloader itself is limited -- modules are loaded from the hard drive as needed to expand functionality (e.g. for [[LVM]] or RAID support).<br />
<br />
* Device naming has changed between GRUB and GRUB2. Partitions are numbered from 1 instead of 0 while drives are still numbered from 0, and prefixed with partition-table type. For example, {{ic|/dev/sda1}} would be referred to as {{ic|(hd0,msdos1)}} (for MBR) or {{ic|(hd0,gpt1)}} (for GPT) using GRUB2.<br />
<br />
=== Preliminary Requirements for GRUB2 ===<br />
<br />
==== BIOS systems ====<br />
<br />
===== [[GPT]] specific instructions =====<br />
<br />
GRUB2 in BIOS-GPT configuration requires a BIOS Boot Partition to embed its {{ic|core.img}} in the absence of post-MBR gap in GPT partitioned systems (which is taken over by the GPT Primary Header and Primary Partition table). This partition is used by GRUB2 only in BIOS-GPT setups. No such partition type exists in case of MBR partitioning (at least not for GRUB2). This partition is also not required if the system is UEFI based, as no embedding of bootsectors takes place in that case. Syslinux does not require this partition.<br />
<br />
For a BIOS-GPT configuration, create a 2 MiB partition using cgdisk or GNU Parted with no filesystem. The location of the partition in the partition table does not matter but it should be within the first 2 TiB region of the disk. It is advisable to put it somewhere in the beginning of the disk before the /boot partition. Set the partition type to "EF02" in cgdisk or {{ic|set <BOOT_PART_NUM> bios_grub on}} in GNU Parted.<br />
<br />
{{Note|This partition should be created before {{ic|grub-install}} or {{ic|grub-setup}} is run or before the '''Install Bootloader''' step of the Archlinux installer (if GRUB2 BIOS is selected as bootloader).}}<br />
<br />
===== [[MBR]] aka msdos partitioning specific instructions =====<br />
<br />
Usually the post-MBR gap (after the 512 byte MBR region and before the start of the 1st partition) in many MBR (or msdos disklabel) partitioned systems is 32 KiB when DOS compatibility cylinder alignment issues are satisfied in the partition table. However a post-MBR gap of about 1 to 2 MiB is recommended to provide sufficient room for embedding GRUB2's {{ic|core.img}} ([https://bugs.archlinux.org/task/24103]). It is advisable to use a partitioner which supports 1 MiB partition alignment to obtain this space as well as satisfy other non-512 byte sector issues (which are unrelated to embedding of {{ic|core.img}}).<br />
<br />
If you do not dual-boot with MS Windows (any version) in BIOS systems, it is advisable to switch to GPT partitioning - [[GUID_Partition_Table#Convert_from_MBR_to_GPT_without_data_loss]]<br />
<br />
{{Note|Create the 2MiB partition mentioned above BEFORE you convert to GPT. If you do not, gparted will not resize your boot partition to allow its creation, and when you reboot GRUB2 will not know where to look.}}<br />
<br />
==== UEFI systems ====<br />
<br />
===== Create and Mount the UEFI SYSTEM PARTITION =====<br />
<br />
Follow [[Unified_Extensible_Firmware_Interface#Create_an_UEFI_System_Partition_in_Linux]] for instructions on creating a UEFI SYSTEM PARTITION. Then mount the UEFI SYSTEM PARTITION at {{ic|/boot/efi}}. If you have mounted the UEFISYS partition in some other mountpoint, replace {{ic|/boot/efi}} in the below instructions with that mountpoint:<br />
<br />
# mkdir -p /boot/efi<br />
# mount -t vfat <UEFISYS_PART_DEVICE> /boot/efi<br />
<br />
Create a <UEFI_SYSTEM_PARTITION>{{ic|/efi}} directory, if it does not exist:<br />
<br />
# mkdir -p /boot/efi/efi<br />
<br />
== Installation ==<br />
<br />
=== During Arch Linux installation ===<br />
<br />
* Skip the '''Install Bootloader''' step and exit the installer.<br />
* Configure the network:<br />
# aif -p partial-configure-network<br />
This will bring up a prompt; put in the network interface to use, (e.g., {{ic|eth0}}) and use DHCP for easy configuration.<br />
* If you did not configure the installed system's {{ic|/etc/resolv.conf}} file during installation (for instance, if you plan to let DHCP generate it later), you will need to copy the one generated by AIF when it configured the network:<br />
# cp /etc/resolv.conf /mnt/etc/resolv.conf<br />
* If you run into network issues in the pacman update step below, you may have needed to install the {{Pkg|net-tools}} package.<br />
* Check and see if the {{ic|dm_mod}} module is loaded. If it is not, load it manually (you might need {{Pkg|grub2-bios}}):<br />
# lsmod | grep dm_mod<br />
# modprobe dm-mod<br />
{{Note|This is necessary at this point, and cannot be postponed after the chroot. If you try to use modprobe in a chroot environment that has a later kernel version from that of the installing device (at the time of writing, 2.6.33), modprobe will fail. This happens routinely using the Arch "net" installations.}}<br />
* From the installer's live shell, chroot to the installed system:<br />
# mount -o bind /dev /mnt/dev<br />
# mount -t proc /proc /mnt/proc/<br />
# mount -t sysfs /sys /mnt/sys/<br />
# chroot /mnt bash<br />
* Update pacman's database:<br />
# pacman-db-upgrade<br />
* Refresh the package list (with an extra {{ic|-y}} flag to force a refresh of all package lists even if they appear to be up to date):<br />
# pacman -Syy<br />
* Install the GRUB2 package as mentioned in the section [[#From a running Arch Linux]] (Note that the {{ic|dm-mod}} module has already been loaded, no need to do that again).<br />
<br />
=== From a running Arch Linux ===<br />
<br />
==== BIOS systems ====<br />
<br />
===== Backup Important Data =====<br />
<br />
Though a GRUB2 installation should run smoothly, it is strongly recommended to make a backup before installing {{Pkg|grub2-bios}}.<br />
<br />
* copy GRUB modules and configuration:<br />
<br />
# cp -a /boot/grub /path/to/backup/<br />
<br />
* backup the MBR and GRUB Legacy stage 1.5:<br />
<br />
# dd if=/dev/sdX of=/path/to/backup/first-sectors bs=512 count=63<br />
<br />
Replace {{ic|/dev/sd'''X'''}} with your actual disk path.<br />
<br />
{{Note|This command backs up the partition table too. Be careful while restoring if you've changed your partition setup in the meantime}}<br />
<br />
To backup only the MBR boot code use:<br />
<br />
# dd if=/dev/sdX of=/path/to/backup/mbr-boot-code bs=440 count=1<br />
<br />
You may now lightly remove {{ic|/boot/grub/}} with:<br />
<br />
# rm -rf /boot/grub<br />
<br />
and follow the instructions below. You know that if things get nasty, you could reboot your system thanks to an installation media and:<br />
<br />
* move old GRUB Legacy or GRUB2 files out of the way:<br />
<br />
# mv /boot/grub /boot/grub.nonfunctional<br />
<br />
* copy GRUB Legacy back to {{ic|/boot}}:<br />
<br />
# cp -a /path/to/backup/grub /boot/<br />
<br />
* replace MBR and next 62 sectors of sda with backed up copy (DANGEROUS!):<br />
<br />
# dd if=/path/to/backup/first-sectors of=/dev/sdX bs=512 count=63<br />
<br />
{{Note|This command also restores the partition table so be careful.}}<br />
<br />
To restore only the MBR boot code use:<br />
<br />
# dd if=/path/to/backup/mbr-boot-code of=/dev/sdX bs=440 count=1<br />
<br />
===== Install grub2-bios package =====<br />
<br />
The GRUB2 package can be installed with pacman (and will replace {{Pkg|grub}}, if it is installed):<br />
<br />
# pacman -S grub2-bios<br />
<br />
{{Note|Simply installing the package won't update the {{ic|/boot/grub/i386-pc/core.img}} file and the GRUB2 modules in {{ic|/boot/grub/i386-pc}}. You need to update them manually using {{ic|grub-install}} as explained below.}}<br />
<br />
Also load the device-mapper kernel module without which {{ic|grub-probe}} does not reliably detect disks and partitions:<br />
<br />
# modprobe dm-mod<br />
<br />
===== Install grub2-bios boot files =====<br />
<br />
There are 3 ways to install GRUB2 boot files in BIOS booting:<br />
*[[#Install_to_440-byte_MBR_boot_code_region]] (recommended) , <br />
*[[#Install_to_Partition_or_Partitionless_Disk]] (not recommended),<br />
*[[#Generate_core.img_alone]] (safest method, but requires another BIOS bootloader like [[grub-legacy]] or [[syslinux]] to be installed to chainload {{ic|/boot/grub/i386-pc/core.img}}). <br />
<br />
====== Install to 440-byte MBR boot code region ======<br />
<br />
To setup {{ic|grub2-bios}} in the 440-byte Master Boot Record boot code region, populate the {{ic|/boot/grub}} directory, generate the {{ic|/boot/grub/i386-pc/core.img}} file, and embed it in the 32 KiB (minimum size - varies depending on partition alignment) post-MBR gap (MBR disks) or in BIOS Boot Partition (GPT disks), run:<br />
<br />
# grub-install --directory=/usr/lib/grub/i386-pc --target=i386-pc --boot-directory=/boot --recheck --debug /dev/sda<br />
<br />
where {{ic|/dev/sda}} is the destination of the installation (in this case the MBR of the first SATA disk). If you use [[LVM]] for your {{ic|/boot}}, you can install GRUB2 on multiple physical disks. <br />
<br />
The {{ic|--no-floppy}} tells {{ic|grub2-bios}} utilities not to search for any floppy devices which reduces the overall execution time of {{ic|grub-install}} on many systems (it will also prevent the issue below from occurring). Otherwise you get an error that looks like this:<br />
<br />
grub-probe: error: Cannot get the real path of '/dev/fd0'<br />
Auto-detection of a filesystem module failed.<br />
Please specify the module with the option '--modules' explicitly.<br />
<br />
{{Note|{{ic|--no-floppy}} has been removed from {{ic|grub-install}} in 2.00~beta2 upstream release, and replaced with {{ic|--allow-floppy}}.}}<br />
<br />
{{Warning|Make sure to check the {{ic|/boot}} directory if you use the latter. Sometimes the {{ic| boot-directory}} parameter creates another {{ic|/boot}} folder inside of {{ic|/boot}}. A wrong install would look like: {{ic|/boot/boot/grub/}}.}}<br />
<br />
====== Install to Partition or Partitionless Disk ======<br />
<br />
{{Note|{{ic|grub2-bios}} (any version - including upstream Bazaar repo) does not encourage installation to a partition boot sector or a partitionless disk like GRUB Legacy or syslinux does. This kind of setup is prone to breakage, especially during updates, and is not supported by Arch devs.}}<br />
<br />
To set up {{ic|grub2-bios}} to a partition boot sector, to a partitionless disk (also called superfloppy) or to a floppy disk, run (using for example {{ic|/dev/sda1}} as the {{ic|/boot}} partition):<br />
<br />
# chattr -i /boot/grub/i386-pc/core.img<br />
# grub-install --directory=/usr/lib/grub/i386-pc --target=i386-pc --boot-directory=/boot --recheck --force --debug /dev/sda1<br />
# chattr +i /boot/grub/i386-pc/core.img<br />
<br />
You need to use the {{ic|--force}} option to allow usage of blocklists and should not use {{ic|1=--grub-setup=/bin/true}} (which is similar to simply generating {{ic|core.img}}).<br />
<br />
{{ic|grub-install}} will give out warnings like which should give you the idea of what might go wrong with this approach:<br />
<br />
/sbin/grub-setup: warn: Attempting to install GRUB to a partitionless disk or to a partition. This is a BAD idea.<br />
/sbin/grub-setup: warn: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. <br />
However, blocklists are UNRELIABLE and their use is discouraged.<br />
<br />
Without {{ic|--force}} you may get the below error and {{ic|grub-setup}} will not setup its boot code in the partition boot sector:<br />
<br />
/sbin/grub-setup: error: will not proceed with blocklists<br />
<br />
With {{ic|--force}} you should get:<br />
<br />
Installation finished. No error reported.<br />
<br />
The reason why {{ic|grub-setup}} does not by default allow this is because in case of partition or a partitionless disk is that {{ic|grub2-bios}} relies on embedded blocklists in the partition bootsector to locate the {{ic|/boot/grub/i386-pc/core.img}} file and the prefix dir {{ic|/boot/grub}}. The sector locations of {{ic|core.img}} may change whenever the filesystem in the partition is being altered (files copied, deleted etc.). For more info see https://bugzilla.redhat.com/show_bug.cgi?id=728742 and https://bugzilla.redhat.com/show_bug.cgi?id=730915.<br />
<br />
The workaround for this is to set the immutable flag on {{ic|/boot/grub/i386-pc/core.img}} (using chattr command as mentioned above) so that the sector locations of the {{ic|core.img}} file in the disk is not altered. The immutable flag on {{ic|/boot/grub/i386-pc/core.img}} needs to be set only if {{ic|grub2-bios}} is installed to a partition boot sector or a partitionless disk, not in case of installtion to MBR or simple generation of {{ic|core.img}} without embedding any bootsector (mentioned above).<br />
<br />
====== Generate core.img alone ======<br />
<br />
To populate the {{ic|/boot/grub}} directory and generate a {{ic|/boot/grub/i386-pc/core.img}} file '''without''' embedding any {{ic|grub2-bios}} bootsector code in the MBR, post-MBR region, or the partition bootsector, add {{ic|1=--grub-setup=/bin/true}} to {{ic|grub-install}}:<br />
<br />
# grub-install --directory=/usr/lib/grub/i386-pc --target=i386-pc --grub-setup=/bin/true --boot-directory=/boot --recheck --debug /dev/sda<br />
<br />
You can then chainload GRUB2's {{ic|core.img}} from GRUB Legacy or syslinux as a Linux kernel or a multiboot kernel.<br />
<br />
===== Generate GRUB2 BIOS Config file =====<br />
<br />
Finally, generate a configuration for GRUB2 (this is explained in greater detail in the Configuration section):<br />
<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
{{Note|The file path is {{ic|/boot/grub/grub.cfg}}, NOT {{ic|/boot/grub/i386-pc/grub.cfg}}.}}<br />
<br />
If grub2 complains about "no suitable mode found" while booting, go to [[#Correct_GRUB2_No_Suitable_Mode_Found_Error]].<br />
<br />
If {{ic|grub-mkconfig}} fails, convert your {{ic|/boot/grub/menu.lst}} file to {{ic|/boot/grub/grub.cfg}} using:<br />
<br />
# grub-menulst2cfg /boot/grub/menu.lst /boot/grub/grub.cfg<br />
<br />
For example:<br />
<br />
{{hc|/boot/grub/menu.lst|<nowiki><br />
default=0<br />
timeout=5<br />
<br />
title Arch Linux Stock Kernel<br />
root (hd0,0)<br />
kernel /vmlinuz-linux root=/dev/sda2 ro<br />
initrd /initramfs-linux.img<br />
<br />
title Arch Linux Stock Kernel Fallback<br />
root (hd0,0)<br />
kernel /vmlinuz-linux root=/dev/sda2 ro<br />
initrd /initramfs-linux-fallback.img<br />
</nowiki>}}<br />
<br />
{{hc|/boot/grub/grub.cfg|<nowiki><br />
set default='0'; if [ x"$default" = xsaved ]; then load_env; set default="$saved_entry"; fi<br />
set timeout=5<br />
<br />
menuentry 'Arch Linux Stock Kernel' {<br />
set root='(hd0,1)'; set legacy_hdbias='0'<br />
legacy_kernel '/vmlinuz-linux' '/vmlinuz-linux' 'root=/dev/sda2' 'ro'<br />
legacy_initrd '/initramfs-linux.img' '/initramfs-linux.img'<br />
<br />
}<br />
<br />
menuentry 'Arch Linux Stock Kernel Fallback' {<br />
set root='(hd0,1)'; set legacy_hdbias='0'<br />
legacy_kernel '/vmlinuz-linux' '/vmlinuz-linux' 'root=/dev/sda2' 'ro'<br />
legacy_initrd '/initramfs-linux-fallback.img' '/initramfs-linux-fallback.img'<br />
}<br />
</nowiki>}}<br />
<br />
If you forgot to create a GRUB2 {{ic|/boot/grub/grub.cfg}} config file and simply rebooted into GRUB2 Command Shell, type:<br />
<br />
sh:grub> insmod legacycfg<br />
sh:grub> legacy_configfile ${prefix}/menu.lst<br />
<br />
Boot into Arch and re-create the proper GRUB2 {{ic|/boot/grub/grub.cfg}} config file.<br />
<br />
{{Note|This option works only in BIOS systems, not in UEFI systems.}}<br />
<br />
===== Multiboot in BIOS =====<br />
<br />
====== Boot Microsoft Windows installed in BIOS-MBR mode ======<br />
<br />
{{Note|GRUB2 supports booting {{ic|bootmgr}} directly and chainload of partition boot sector is no longer required to boot Windows in a BIOS-MBR setup.}}<br />
<br />
Find the UUID of the NTFS filesystem of the Windows's SYSTEM PARTITION where the {{ic|bootmgr}} and its files reside. For example, if Windows {{ic|bootmgr}} exists at {{ic|/media/Windows/bootmgr}}:<br />
<br />
# grub-probe --target=fs_uuid /media/Windows/bootmgr<br />
69B235F6749E84CE<br />
<br />
Then, add the below code to {{ic|/etc/grub.d/40_custom}} and regenerate {{ic|grub.cfg}} with {{ic|grub-mkconfig}} as explained above to chainload Windows (Vista, 7 or 8) installed in BIOS-MBR mode:<br />
<br />
menuentry "Microsoft Windows 7 BIOS-MBR" {<br />
insmod part_msdos<br />
insmod ntfs<br />
insmod search_fs_uuid<br />
insmod ntldr <br />
search --fs-uuid --no-floppy --set=root 69B235F6749E84CE<br />
ntldr /bootmgr<br />
}<br />
<br />
For Windows XP:<br />
<br />
menuentry "Microsoft Windows XP" {<br />
insmod part_msdos<br />
insmod ntfs<br />
insmod search_fs_uuid<br />
insmod ntldr <br />
search --fs-uuid --no-floppy --set=root 69B235F6749E84CE<br />
ntldr /ntldr<br />
}<br />
<br />
==== [[UEFI]] systems ====<br />
<br />
===== Install grub2-uefi package =====<br />
<br />
{{Note|Unless specified as EFI 1.x , EFI and UEFI terms are used interchangeably to denote UEFI 2.x firmware. Also unless stated explicitely, the instructions are general and not Mac specific. Some of them may not work or may be different in Macs. Apple's EFI implementation is neither a EFI 1.x version nor UEFI 2.x version but mixes up both. This kind of firmware does not fall under any one UEFI Specification version and is therefore not a standard UEFI firmware.}}<br />
<br />
GRUB2 UEFI bootloader is available in Arch Linux only from version 1.99~rc1. To install, first [https://wiki.archlinux.org/index.php/Unified_Extensible_Firmware_Interface#Detecting_UEFI_Firmware_Arch Detect which UEFI firmware arch] you have (either x86_64 or i386).<br />
<br />
Depending on that, install the appropriate package<br />
<br />
For 64-bit aka x86_64 UEFI firmware:<br />
# pacman -S grub2-efi-x86_64<br />
<br />
For 32-bit aka i386 UEFI firmware:<br />
# pacman -S grub2-efi-i386<br />
<br />
{{Note|Simply installing the package won't update the {{ic|grub.efi}} file and the GRUB2 modules in the UEFI System Partition. You need to do this manually using {{ic|grub-install}} as explained below.}}<br />
<br />
Also load the device-mapper kernel module without which {{ic|grub-probe}} does not reliably detect disks and partitions:<br />
<br />
# modprobe dm-mod<br />
<br />
===== Install grub2-uefi boot files =====<br />
<br />
====== Install to UEFI SYSTEM PARTITION ======<br />
<br />
{{Note|The below commands assume you are using {{ic|grub2-efi-x86_64}} (for {{ic|grub2-efi-i386}} replace {{ic|x86_64}} with {{ic|i386}} in the below commands).}}<br />
<br />
The UEFI system partition will need to be mounted at {{ic|/boot/efi/}} for the GRUB2 install script to detect it:<br />
<br />
# mkdir -p /boot/efi<br />
# mount -t vfat /dev/sdXY /boot/efi<br />
<br />
Install GRUB UEFI application to {{ic|/boot/efi/efi/arch_grub}} and its modules to {{ic|/boot/grub/x86_64-efi}} (recommended) using:<br />
<br />
# grub-install --directory=/usr/lib/grub/x86_64-efi --target=x86_64-efi --root-directory=/boot/efi\<br />
--boot-directory=/boot --bootloader-id=arch_grub --recheck --debug<br />
<br />
If you want to install grub2 modules and {{ic|grub.cfg}} at the directory {{ic|/boot/efi/efi/grub}} and the {{ic|grubx64.efi}} application at {{ic|/boot/efi/efi/arch_grub}} use:<br />
<br />
# grub-install --directory=/usr/lib/grub/x86_64-efi --target=x86_64-efi --root-directory=/boot/efi\<br />
--boot-directory=/boot/efi/efi --bootloader-id=arch_grub --recheck --debug<br />
<br />
In this case {{ic|grub2-efi-x86_64}} will be installed into {{ic|/boot/grub}}, making the behavior consistent with the BIOS verion of GRUB2, but this is not recommended if you use both {{ic|grub2-bios}} and {{ic|grub2-efi-x86_64}} in your system, as this will overwrite {{ic|grub2-bios }}modules in {{ic|/boot/grub}}.<br />
<br />
The {{ic|--root-directory}} option mentions the mountpoint of UEFI SYSTEM PARTITION , {{ic|--bootloader-id}} mentions the name of the directory used to store the {{ic|grubx64.efi}} file and {{ic|--boot-directory}} mentions the directory wherein the actual modules will be installed (and into which {{ic|grub.cfg}} should be created).<br />
<br />
The actual paths are:<br />
<br />
<root-directory>/<efi or EFI>/<bootloader-id>/grubx64.efi<br />
<br />
<boot-directory>/grub/x86_64-efi/<all modules, grub.efi, core.efi, grub.cfg><br />
<br />
{{Note|the {{ic|--bootloader-id}} option does not change {{ic|<boot-directory>/grub}}, i.e. you cannot install the modules to {{ic|<boot-directory>/<bootloader-id>}}, the path is hard-coded to {{ic|<boot-directory>/grub}}.}}<br />
<br />
In {{ic|<nowiki>--root-directory=/boot/efi --boot-directory=/boot/efi/efi --bootloader-id=grub</nowiki>}}:<br />
<br />
<root-directory>/<efi or EFI>/<bootloader-id> == <boot-directory>/grub == /boot/efi/efi/grub<br />
<br />
In {{ic|<nowiki>--root-directory=/boot/efi --boot-directory=/boot/efi/efi --bootloader-id=arch_grub</nowiki>}}:<br />
<br />
<root-directory>/<efi or EFI>/<bootloader-id> == /boot/efi/efi/arch_grub<br />
<boot-directory>/grub == /boot/efi/efi/grub<br />
<br />
In {{ic|<nowiki>--root-directory=/boot/efi --boot-directory=/boot --bootloader-id=arch_grub</nowiki>}}:<br />
<br />
<root-directory>/<efi or EFI>/<bootloader-id> == /boot/efi/efi/arch_grub<br />
<boot-directory>/grub == /boot/grub<br />
<br />
In {{ic|<nowiki>--root-directory=/boot/efi --boot-directory=/boot --bootloader-id=grub</nowiki>}}:<br />
<br />
<root-directory>/<efi or EFI>/<bootloader-id> == /boot/efi/efi/grub<br />
<boot-directory>/grub == /boot/grub<br />
<br />
The {{ic|<nowiki><root-directory>/<efi or EFI>/<bootloader-id>/grubx64.efi</nowiki>}} is an exact copy of {{ic|<nowiki><boot-directory>/grub/x86_64-efi/core.efi</nowiki>}}.<br />
<br />
{{Note|This behavior of {{ic|--root-directory}}, {{ic|--boot-directory}}, and {{ic|--bootloader-id}} options are specific to UEFI systems and does not occur is BIOS mode. In {{ic|grub-install}}, {{ic|--root-directory}} is deprecated and {{ic|--bootloader-id}} does not exist.}}<br />
<br />
In all the cases the UEFI SYSTEM PARTITION should be mounted for {{ic|grub-install}} to install {{ic|grubx64.efi}} in it, which will be launched by the firmware (using the {{ic|efibootmgr}} created boot entry in non-Mac systems).<br />
<br />
If you notice carefully, there is no <device_path> option (Eg: {{ic|/dev/sda}}) at the end of the {{ic|grub-install}} command unlike the case of setting up GRUB2 for BIOS systems. Any <device_path> provided will be ignored by the install script as UEFI bootloaders do not use MBR or Partition boot sectors at all.<br />
<br />
You may now be able to UEFI boot your system by creating a {{ic|grub.cfg}} file by following [[#Generate_GRUB2_UEFI_Config_file]] and [[#Create_GRUB2_entry_in_the_Firmware_Boot_Manager]].<br />
<br />
===== Create GRUB2 entry in the Firmware Boot Manager =====<br />
<br />
====== Non-Mac UEFI systems ======<br />
<br />
{{ic|grub-install}} will ensure that {{ic|/boot/efi/efi/arch_grub/grubx64.efi}} is launched by default if it detects {{ic|efibootmgr}} and if it is able to access UEFI Runtime Services. Follow [[Unified_Extensible_Firmware_Interface#efibootmgr]] for more info.<br />
<br />
If you have problems running GRUB2 in UEFI mode you can try the following (worked on an ASUS Z68 mainboard):<br />
<br />
# cp /boot/efi/efi/arch_grub/grubx64.efi /boot/efi/shellx64.efi<br />
<br />
or<br />
<br />
# cp /boot/efi/efi/arch_grub/grubx64.efi /boot/efi/efi/shellx64.efi<br />
<br />
or<br />
<br />
# cp /boot/efi/efi/arch_grub/grubx64.efi /boot/efi/efi/shell/shellx64.efi<br />
<br />
After this launch the UEFI Shell from the UEFI setup/menu (in ASUS UEFI BIOS, switch to advanced mode, press Exit in the top right corner and choose "Launch EFI shell from filesystem device"). The GRUB2 menu will show up and you can boot into your system. Afterwards you can use efibootmgr to setup a menu entry (see above).<br />
<br />
====== Apple Mac EFI systems ======<br />
<br />
{{Note|TODO: GRUB upstream Bazaar mactel branch http://bzr.savannah.gnu.org/lh/grub/branches/mactel/changes . No further update from grub developers.}}<br />
{{Note|TODO: Experimental "bless" utility for Linux by Fedora developers - {{AUR|mactel-boot}}. Requires more testing.)}}<br />
<br />
Use bless command from within Mac OS X to set {{ic|grubx64.efi}} as the default boot option. You can also boot from the Mac OS X install disc and launch a Terminal there if you only have Linux installed. In the Terminal, create a directory and mount the EFI System Partition:<br />
<br />
# cd /Volumes<br />
# mkdir efi<br />
# mount -t msdos /dev/disk0s1 /Volumes/efi<br />
<br />
Then run bless on {{ic|grub.efi}} and on the EFI partition to set them as the default boot options.<br />
<br />
# bless --folder=/Volumes/efi --file=/Volumes/efi/efi/arch_grub/grubx64.efi --setBoot<br />
# bless --mount=/Volumes/efi --file=/Volumes/efi/efi/arch_grub/grubx64.efi --setBoot<br />
<br />
More info at https://help.ubuntu.com/community/UEFIBooting#Apple_Mac_EFI_systems_.28both_EFI_architecture.29.<br />
<br />
===== Generate GRUB2 UEFI Config file =====<br />
<br />
Finally, generate a configuration for GRUB2 (this is explained in greater detail in the Configuration section):<br />
<br />
# grub-mkconfig -o <boot-directory>/grub/grub.cfg<br />
<br />
{{Note|The file path is {{ic|<boot-directory>/grub/grub.cfg}}, NOT {{ic|<boot-directory>/grub/x86_64-efi/grub.cfg}}.}}<br />
<br />
If you used {{ic|<nowiki>--boot-directory=/boot</nowiki>}}:<br />
<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
If you used {{ic|<nowiki>--boot-directory=/boot/efi/efi</nowiki>}}:<br />
<br />
# grub-mkconfig -o /boot/efi/efi/grub/grub.cfg<br />
<br />
This is independent of the value of {{ic|--bootloader-id}} option.<br />
<br />
If GRUB2 complains about "no suitable mode found" while booting, try [[#Correct_GRUB2_No_Suitable_Mode_Found_Error]].<br />
<br />
===== Create GRUB2 Standalone UEFI Application =====<br />
<br />
It is possible to create a {{ic|grubx64_standalone.efi}} application which has all the modules embeddded in a memdisk within the uefi application, thus removing the need for having a separate directory populated with all the GRUB2 uefi modules and other related files. This is done using the {{ic|grub-mkstandalone}} command which is included in {{Pkg|grub2-common}} >= 1:1.99-6 package.<br />
<br />
The easiest way to do this would be with the install command already mentioned before, but specifying the modules to include. For example:<br />
<br />
# grub-mkstandalone --directory="/usr/lib/grub/x86_64-efi/" --format="x86_64-efi" --compression="xz" \<br />
--output="/boot/efi/efi/arch_grub/grubx64_standalone.efi" <any extra files you want to include><br />
<br />
The {{ic|grubx64_standalone.efi}} file expects {{ic|grub.cfg}} to be within its $prefix which is {{ic|(memdisk)/boot/grub}}. The memdisk is embedded within the efi app. The {{ic|grub-mkstandlone}} script allow passing files to be included in the memdisk image to be as the arguments to the script (in <any extra files you want to include>).<br />
<br />
If you have the {{ic|grub.cfg}} at {{ic|/home/user/Desktop/grub.cfg}}, then create a temporary {{ic|/home/user/Desktop/boot/grub/}} directory, copy the {{ic|/home/user/Desktop/grub.cfg}} to {{ic|/home/user/Desktop/boot/grub/grub.cfg}}, cd into {{ic|/home/user/Desktop/boot/grub/}} and run:<br />
<br />
# grub-mkstandalone --directory="/usr/lib/grub/x86_64-efi/" --format="x86_64-efi" --compression="xz" \<br />
--output="/boot/efi/efi/arch_grub/grubx64_standalone.efi" "boot/grub/grub.cfg"<br />
<br />
The reason to cd into {{ic|/home/user/Desktop/boot/grub/}} and to pass the file path as {{ic|boot/grub/grub.cfg}} (notice the lack of a leading slash - boot/ vs /boot/ ) is because {{ic|dir1/dir2/file}} is included as {{ic|(memdisk)/dir1/dir2/file}} by the {{ic|grub-mkstandalone}} script. <br />
<br />
If you pass {{ic|/home/user/Desktop/grub.cfg}} the file will be included as {{ic|(memdisk)/home/user/Desktop/grub.cfg}}. If you pass {{ic|/home/user/Desktop/boot/grub/grub.cfg}} the file will be included as {{ic|(memdisk)/home/user/Desktop/boot/grub/grub.cfg}}. That is the reason for cd'ing into {{ic|/home/user/Desktop/boot/grub/}} and passing {{ic|boot/grub/grub.cfg}}, to includ the file as {{ic|(memdisk)/boot/grub/grub.cfg}}, which is what {{ic|grub.efi}} expects the file to be.<br />
<br />
You need to create an UEFI Boot Manager entry for {{ic|/boot/efi/efi/arch_grub/grubx64_standalone.efi}} using {{ic|efibootmgr}}. Follow [[#Create GRUB2 entry in the Firmware Boot Manager]].<br />
<br />
===== Multiboot in UEFI =====<br />
<br />
====== Chainload Microsoft Windows x86_64 UEFI-GPT ======<br />
<br />
Find the UUID of the FAT32 filesystem in the UEFI SYSTEM PARTITION where the Windows UEFI Bootloader files reside. For example, if Windows {{ic|bootmgfw.efi}} exists at {{ic|/boot/efi/efi/Microsoft/Boot/bootmgfw.efi}} (ignore the upper-lower case differences since that is immaterial in FAT filesystem):<br />
<br />
# grub-probe --target=fs_uuid /boot/efi/efi/Microsoft/Boot/bootmgfw.efi<br />
1ce5-7f28<br />
<br />
# grub-probe --target=hints_string /boot/efi/efi/Microsoft/Boot/bootmgfw.efi<br />
--hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1<br />
<br />
Then, add this code to {{ic|/boot/grub/grub.cfg}} OR {{ic|/boot/efi/efi/grub/grub.cfg}} to chainload Windows x86_64 (Vista SP1+, 7 or 8) installed in UEFI-GPT mode:<br />
<br />
menuentry "Microsoft Windows x86_64 UEFI-GPT" {<br />
insmod part_gpt<br />
insmod fat<br />
insmod search_fs_uuid<br />
insmod chain<br />
search --fs-uuid --no-floppy --set=root --hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1 1ce5-7f28<br />
chainloader /efi/Microsoft/Boot/bootmgfw.efi<br />
}<br />
<br />
== Configuration ==<br />
<br />
You can also choose to automatically generate or manually edit {{ic|grub.cfg}}.<br />
<br />
{{Note|If GRUB2 was installed with the {{ic|--boot-directory}} option set, the {{ic|grub.cfg}} file must be placed in the same directory as {{ic|grubx64.efi}}. Otherwise, the {{ic|grub.cfg}} file goes in {{ic|/boot/grub/}}, just like in the BIOS version of GRUB2.}}<br />
<br />
{{Note|Here is a quite complete description of how to configure GRUB2: http://members.iinet.net/~herman546/p20/GRUB2%20Configuration%20File%20Commands.html }}<br />
<br />
=== Automatically generating using grub-mkconfig (Recommended) ===<br />
<br />
The GRUB2 {{ic|menu.lst}} equivalent configuration files are {{ic|/etc/default/grub}} and {{ic|/etc/grub.d/*}}. {{ic|grub-mkconfig}} uses these files to generate {{ic|grub.cfg}}. By default the script outputs to stdout. To generate a {{ic|grub.cfg}} file run the command:<br />
<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
{{ic|/etc/grub.d/10_linux}} is set to automatically add menu items for Arch linux that work out of the box, to any generated configuration. Other operating systems may need to be added manually by editing {{ic|/etc/grub.d/40_custom}}<br />
<br />
==== Additional arguments ====<br />
<br />
To pass custom additional arguments to the linux image, you can set the {{ic|GRUB_CMDLINE_LINUX}} variable in {{ic|/etc/default/grub}}. This is analogous to adding commands to the kernel line in legacy GRUB.<br />
<br />
For example, use {{ic|<nowiki>GRUB_CMDLINE_LINUX="resume=/dev/sdaX"</nowiki>}} where {{ic|sda'''X'''}} is your swap partition to enable resume after hibernation.<br />
<br />
=== Manually creating grub.cfg ===<br />
<br />
A basic GRUB config file uses the following options<br />
* {{ic|(hdX,Y)}} is the partition {{ic|Y}} on disk {{ic|X}}, partition numbers starting at 1, disk numbers starting at 0<br />
* {{ic|1=set default=N}} is the default boot entry that is chosen after timeout for user action<br />
* {{ic|1=set timeout=M}} is the time {{ic|M}} to wait in seconds for a user selection before default is booted<br />
* {{ic|<nowiki>menuentry "title" {entry options}</nowiki>}} is a boot entry titled {{ic|title}}<br />
* {{ic|1=set root=(hdX,Y)}} sets the boot partition, where the kernel and GRUB modules are stored (boot need not be a separate partition, and may simply be a directory under the "root" partition ({{ic|/}})<br />
<br />
An example configuration:<br />
<br />
{{hc<br />
|/boot/grub/grub.cfg<br />
|<nowiki><br />
# Config file for GRUB2 - The GNU GRand Unified Bootloader<br />
# /boot/grub/grub.cfg<br />
<br />
# DEVICE NAME CONVERSIONS<br />
#<br />
# Linux Grub<br />
# -------------------------<br />
# /dev/fd0 (fd0)<br />
# /dev/sda (hd0)<br />
# /dev/sdb2 (hd1,2)<br />
# /dev/sda3 (hd0,3)<br />
#<br />
<br />
# Timeout for menu<br />
set timeout=5<br />
<br />
# Set default boot entry as Entry 0<br />
set default=0<br />
<br />
# (0) Arch Linux<br />
menuentry "Arch Linux" {<br />
set root=(hd0,1)<br />
linux /vmlinuz-linux root=/dev/sda3 ro<br />
initrd /initramfs-linux.img<br />
}<br />
<br />
## (1) Windows<br />
#menuentry "Windows" {<br />
#set root=(hd0,3)<br />
#chainloader +1<br />
#}<br />
</nowiki>}}<br />
<br />
=== Dual-booting ===<br />
<br />
{{Note|If you want GRUB2 to automatically search for other systems, you may wish to install {{Pkg|os-prober}}.}}<br />
<br />
==== Using grub-mkconfig ====<br />
The best way to add other entries is editing the {{ic|/etc/grub.d/40_custom}}. The entries in this file will be automatically added when running {{ic|grub-mkconfig}}.<br />
After adding the new lines, run:<br />
# grub-mkconfig -o /boot/grub/grub.cfg <br />
to generate an updated {{ic|grub.cfg}}.<br />
<br />
===== With GNU/Linux =====<br />
<br />
Assuming that the other distro is on partition {{ic|sda2}}:<br />
<br />
menuentry "Other Linux" {<br />
set root=(hd0,2)<br />
linux /boot/vmlinuz (add other options here as required)<br />
initrd /boot/initrd.img (if the other kernel uses/needs one)<br />
}<br />
<br />
===== With FreeBSD =====<br />
<br />
Requires that FreeBSD is installed on a single partition with UFS. Assuming it is installed on {{ic|sda4}}:<br />
<br />
menuentry "FreeBSD" {<br />
set root=(hd0,4)<br />
chainloader +1<br />
}<br />
<br />
===== With Windows =====<br />
<br />
This assumes that your Windows partition is {{ic|sda3}}.<br />
<br />
# (2) Windows XP<br />
menuentry "Windows XP" {<br />
set root=(hd0,3)<br />
chainloader (hd0,3)+1<br />
}<br />
<br />
If the Windows Bootloader is on an entirely different harddrive than GRUB, it may be necessary to trick Windows into believing that it is in fact the first harddrive. This was possible in the old GRUB with {{ic|map}} and is now done with {{ic|drivemap}}. Assume GRUB is on {{ic|hd0}} and windows on {{ic|hd2}}, you need to add the following after {{ic|set root}}:<br />
<br />
drivemap -s hd0 hd2<br />
<br />
==== With Windows via EasyBCD and NeoGRUB ====<br />
<br />
Since EasyBCD's NeoGRUB currently does not understand the GRUB2 menu format, chainload to it by replacing the contents of your {{ic|C:\NST\menu.lst}} file with lines similar to the following:<br />
<br />
default 0<br />
timeout 1<br />
<br />
title Chainload into GRUB v2<br />
root (hd0,7)<br />
kernel /boot/grub/i386-pc/core.img<br />
<br />
===Visual Configuration===<br />
<br />
In GRUB2 it is possible, by default, to change the look of the menu. Make sure to initialize, if not done already, GRUB2 graphical terminal, gfxterm, with proper video mode, gfxmode, in GRUB2. This can be seen in the section [[#Correct_GRUB2_No_Suitable_Mode_Found_Error]]. This video mode is passed by GRUB2 to the linux kernel via 'gfxpayload' so any visual configurations need this mode in order to be in effect.<br />
<br />
====Setting the framebuffer resolution ====<br />
<br />
GRUB2 can set the framebuffer for both GRUB2 itself and the kernel. The old {{ic|1=vga=}} way is deprecated. The preferred method is editing {{ic|/etc/default/grub}} as the following sample:<br />
<br />
GRUB_GFXMODE=1024x768x32<br />
GRUB_GFXPAYLOAD_LINUX=keep<br />
<br />
To generate the changes, run: <br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
The {{ic|gfxpayload}} property will make sure the kernel keeps the resolution.<br />
<br />
{{Note|If this example does not work for you try to replace {{ic|1=gfxmode="1024x768x32"}} by {{ic|1=vbemode="0x105"}}. Remember to replace the specified resolution with one suitable for your screen.}}<br />
{{Note|To show all the modes you can use {{ic|1=# hwinfo --framebuffer}} (hwinfo is available in [community]), while at GRUB2 prompt you can use the {{ic|1=vbeinfo}} command.}}<br />
<br />
If this method does not work for you, the deprecated {{ic|1=vga=}} method will still work. Just<br />
add it next to the {{ic|1="GRUB_CMDLINE_LINUX_DEFAULT="}} line in {{ic|/etc/default/grub}}<br />
for eg: {{ic|1="GRUB_CMDLINE_LINUX_DEFAULT="quiet splash vga=792"}} will give you a {{ic|1024x768}} resolution.<br />
<br />
You can choose one of these resolutions: {{ic|640×480}}, {{ic|800×600}}, {{ic|1024×768}}, {{ic|1280×1024}}, {{ic|1600×1200}}<br />
<br />
====915resolution hack ====<br />
<br />
Some times for Intel graphic adapters neither {{ic|1=# hwinfo --framebuffer}} nor {{ic|1=vbeinfo}} will show you the desired resolution. In this case you can use {{ic|915resolution}} hack. This hack will temporarily modify video BIOS and add needed resolution. See [http://915resolution.mango-lang.org/ 915resolution's home page]<br />
<br />
In the following I will proceed with the example for my system. Please adjust the recipe for your needs. First you need to find a video mode which will be modified later. For that, run {{ic|915resolution}} in GRUB2 command shell:<br />
915resolution -l<br />
The output will be something like:<br />
Intel 800/900 Series VBIOS Hack : version 0.5.3<br />
...<br />
Mode 30 : 640x480, 8 bits/pixel<br />
...<br />
Next, our purpose is to overwrite mode 30. (You can choose what ever mode you want.) In the file {{ic|/etc/grub.d/00_header}} just before the {{ic|set gfxmode&#61;${GRUB_GFXMODE}}} line insert:<br />
915resolution 30 1440 900<br />
Here we are overwriting the mode {{ic|30}} with {{ic|1440x900}} resolution. Lastly we need to set {{ic|GRUB_GFXMODE}} as described earlier, regenerate GRUB2 configuration file and reboot to test changes:<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
# reboot<br />
<br />
====Background image and bitmap fonts====<br />
<br />
GRUB2 comes with support for background images and bitmap fonts in {{ic|pf2}} format. The unifont font is included in the {{Pkg|grub2-common}} package under the filename {{ic|unicode.pf2}}, or, as only ASCII characters under the name {{ic|ascii.pf2}}. <br />
<br />
Image formats supported include tga, png and jpeg, providing the correct modules are loaded. The maximum supported resolution depends on your hardware.<br />
<br />
Make sure you have set up the proper [https://wiki.archlinux.org/index.php/GRUB2#Setting_the_framebuffer_resolution framebuffer resolution].<br />
<br />
Edit {{ic|/etc/default/grub}} like this:<br />
GRUB_BACKGROUND="/boot/grub/archlinux.tga"<br />
#GRUB_THEME="/path/to/gfxtheme"<br />
<br />
({{ic|archlinux.tga}} is a placeholder; put your file name there)<br />
<br />
{{Note|If you have installed GRUB on a separate partition, {{ic|/boot/grub/archlinux.tga}} becomes {{ic|/grub/archlinux.tga}}.}}<br />
<br />
To generate the changes and add the information into {{ic|grub.cfg}}, run: <br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
If adding the splash image was successful, the user will see {{ic|"Found background image..."}} in the terminal as the command is executed. <br />
If this phrase is not seen, the image information was probably not incorporated into the {{ic|grub.cfg}} file.<br />
<br />
If the image is not displayed, check:<br />
* The path and the filename in {{ic|/etc/default/grub}} are correct.<br />
* The image is of the proper size and format (tga, png, 8-bit jpg).<br />
* The image was saved in the RGB mode, and is not indexed.<br />
* The console mode is not enabled in {{ic|/etc/default/grub}}.<br />
* The command {{ic|grub-mkconfig}} must be executed to place the background image information into the {{ic|/boot/grub/grub.cfg}} file.<br />
<br />
====Theme====<br />
<br />
Here is an example for configuring Starfield theme which was included in GRUB2 package.<br />
<br />
Edit {{ic|/etc/default/grub}}<br />
GRUB_THEME="/boot/grub/themes/starfield/theme.txt"<br />
<br />
Generate the changes:<br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
If configuring the theme was successful, you'll see {{ic|Found theme: /boot/grub/themes/starfield/theme.txt}} in the terminal.<br />
<br />
====Menu colors====<br />
<br />
As in GRUB Legacy (0.9x), you can change the menu colors in GRUB2. The available colors for GRUB2 are at http://www.gnu.org/software/grub/manual/html_node/Theme-file-format.html#Theme-file-format.<br />
Here is an example:<br />
<br />
Edit {{ic|/etc/default/grub}}:<br />
GRUB_COLOR_NORMAL="light-blue/black"<br />
GRUB_COLOR_HIGHLIGHT="light-cyan/blue"<br />
<br />
Generate the changes:<br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
====Hidden menu====<br />
<br />
One of the unique features of GRUB2 is hiding/skipping the menu and showing it by holding {{keypress|Shift}} when needed. You can also adjust whether you want to see the timeout counter.<br />
<br />
Edit {{ic|/etc/default/grub}} as you wish. Here is an example where the comments from the beginning of the two lines have been removed to enable the feature, the timeout has been set to five seconds and to be shown to the user:<br />
GRUB_HIDDEN_TIMEOUT=5<br />
GRUB_HIDDEN_TIMEOUT_QUIET=false<br />
<br />
and run:<br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
=== Other Options ===<br />
<br />
==== LVM ====<br />
<br />
If you use [[LVM]] for your {{ic|/boot}}, add the following before menuentry lines:<br />
<br />
insmod lvm<br />
<br />
and specify your root in the menuentry as:<br />
<br />
set root=(''lvm_group_name''-''lvm_logical_boot_partition_name'')<br />
<br />
Example:<br />
<br />
# (0) Arch Linux<br />
menuentry "Arch Linux" {<br />
insmod lvm<br />
set root=(VolumeGroup-lv_boot)<br />
# you can only set following two lines<br />
linux /vmlinuz-linux root=/dev/mapper/VolumeGroup-root ro<br />
initrd /initramfs-linux.img<br />
}<br />
<br />
==== Raid ====<br />
<br />
GRUB2 provides convenient handling of raid-volumes. You need to add:<br />
insmod raid<br />
<br />
which allows you to address the volume natively. E.g. {{ic|/dev/md0}} becomes:<br />
set root=(md0)<br />
<br />
whereas a partitioned raid-volume (e.g. {{ic|/dev/md0p1}}) becomes:<br />
set root=(md0,1)<br />
<br />
==== Persistent block device naming ====<br />
You can use UUIDs to detect partitions instead of the "old" {{ic|/dev/sd*}} and {{ic|/dev/hd*}} scheming. It has the advantage of detecting partitions by their unique UUIDs, which is needed by some people booting with complicated partition setups.<br />
<br />
UUIDs are used by default in the recent versions of GRUB2 - there is no downside in it anyway except that you need to re-generate the {{ic|grub.cfg}} file every time you resize or reformat your partitions. Remember this when modifying partitions with Live-CD.<br />
<br />
The recent versions of GRUB2 use UUIDs by default. You can re-enable the use of UUIDS by simply commenting the UUID line (this is also what it looks like by default):<br />
#GRUB_DISABLE_LINUX_UUID=true<br />
you can also just set the value as {{ic|false}} as shown here:<br />
GRUB_DISABLE_LINUX_UUID=false<br />
<br />
Either way, do not forget to generate the changes:<br />
grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
==== Using Labels ====<br />
<br />
It is possible to use labels, human-readable strings attached to filesystems, by using the {{ic|--label}} option to {{ic|search}}. First of all, label your existing partition:<br />
# tune2fs -L a <LABEL> <PARTITION><br />
<br />
Then, add an entry using labels. An example of this:<br />
<br />
menuentry "Arch Linux, session texte" {<br />
search --label --no-floppy --set=root archroot<br />
linux /boot/vmlinuz-linux root=/dev/disk/by-label/archroot ro<br />
initrd /boot/initramfs-linux.img<br />
}<br />
<br />
==== Recall previous entry ====<br />
<br />
GRUB2 can remember the last entry you booted from and use this as the default entry to boot from next time. This is useful if you have multiple kernels (i.e., the current Arch one and the LTS kernel as a fallback option) or operating systems. To do this, edit {{ic|/etc/default/grub}} and change the setting of {{ic|GRUB_DEFAULT}}:<br />
<br />
GRUB_DEFAULT=saved<br />
<br />
This ensures that GRUB will default to the saved entry. To enable saving the selected entry, add the following line to {{ic|/etc/default/grub}}:<br />
<br />
GRUB_SAVEDEFAULT=true<br />
<br />
{{Note|Manually added menu items, eg Windows in {{ic|/etc/grub.d/40_custom}}, will need {{ic|savedefault}} added. Remember to regenerate your configuration file.}}<br />
<br />
==== Security ====<br />
<br />
If you want to secure GRUB2 so it is not possible for anyone to change boot parameters or use the command line, you can add a user/password combination to GRUB2's configuration files. To do this, run the command {{ic|grub-mkpasswd_pbkdf2}}. Enter a password and confirm it. The output will look like this:<br />
<br />
{{bc|<nowiki><br />
Your PBKDF2 is grub.pbkdf2.sha512.10000.C8ABD3E93C4DFC83138B0C7A3D719BC650E6234310DA069E6FDB0DD4156313DA3D0D9BFFC2846C21D5A2DDA515114CF6378F8A064C94198D0618E70D23717E82.509BFA8A4217EAD0B33C87432524C0B6B64B34FBAD22D3E6E6874D9B101996C5F98AB1746FE7C7199147ECF4ABD8661C222EEEDB7D14A843261FFF2C07B1269A</nowiki>}}Then, add the following to {{ic|/etc/grub.d/00_header}}:<br />
{{bc|<nowiki>cat << EOF<br />
<br />
set superusers="username"<br />
password_pbkdf2 username <password><br />
<br />
EOF</nowiki>}}<br />
where {{ic|<password>}} is the string generated by {{ic|grub-mkpasswd_pbkdf2}}.<br />
<br />
Regenerate your configuration file. Your GRUB2 command line and boot parameters are now protected.<br />
<br />
==== Root Encryption ====<br />
<br />
To let GRUB2 automatically add the kernel parameters for root encryption,<br />
add {{ic|1=cryptdevice=/dev/yourdevice:label}} to {{ic|GRUB_CMDLINE_LINUX}} in {{ic|/etc/defaults/grub}}.<br />
<br />
Example with root mapped to {{ic|/dev/mapper/root}}:<br />
<br />
GRUB_CMDLINE_LINUX="cryptdevice=/dev/sda2:root"<br />
<br />
Also, disable the usage of UUIDs for the rootfs:<br />
<br />
GRUB_DISABLE_LINUX_UUID=true<br />
<br />
Regenerate the configuration.<br />
<br />
=== Booting an ISO Directly From GRUB2 ===<br />
Edit {{ic|/etc/grub.d/40_custom}} to add an entry for the target ISO. When finished, update the GRUB menu as with the usual {{ic|grub-mkconfig -o /boot/grub/grub.cfg}} (as root).<br />
<br />
==== Arch ISO ====<br />
{{Note|Be sure to adjust the "hdX,Y" in the third line to point to the correct disk/partition number of the isofile. Also adjust the img_dev line to match this same location.}}<br />
<br />
menuentry "Archlinux-2011.08.19-netinstall-x86_64.iso" {<br />
set isofile="/archives/archlinux-2011.08.19-netinstall-x86_64.iso"<br />
loopback loop (hd0,7)$isofile<br />
linux (loop)/arch/boot/x86_64/vmlinuz archisolabel=ARCH_201108 img_dev=/dev/sda7 img_loop=$isofile earlymodules=loop<br />
initrd (loop)/arch/boot/x86_64/archiso.img<br />
}<br />
<br />
==== Ubuntu ISO ====<br />
{{Note|Be sure to adjust the "hdX,Y" in the third line to point to the correct disk/partition number of the isofile. }}<br />
<br />
menuentry "ubuntu-11.04-desktop-amd64.iso" {<br />
set isofile="/path/to/ubuntu-11.04-desktop-amd64.iso"<br />
loopback loop (hdX,Y)$isofile<br />
linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile quiet noeject noprompt splash --<br />
initrd (loop)/casper/initrd.lz<br />
}<br />
<br />
== Using the command shell ==<br />
<br />
Since the MBR is too small to store all GRUB2 modules, only the menu and a few basic commands reside there. The majority of GRUB2 functionality remains in modules in {{ic|/boot/grub}}, which are inserted as needed. In error conditions (e.g. if the partition layout changes) GRUB2 may fail to boot. When this happens, a command shell may appear.<br />
<br />
GRUB2 offers multiple shells/prompts. If there is a problem reading the menu but the bootloader is able to find the disk, you will likely be dropped to the "normal" shell:<br />
sh:grub><br />
<br />
If there is a more serious problem (e.g. GRUB cannot find required files), you may instead be dropped to the "rescue" shell:<br />
grub rescue><br />
<br />
The rescue shell is a restricted subset of the normal shell, offering much less functionality. If dumped to the rescue shell, first try inserting the "normal" module, then starting the "normal" shell:<br />
grub rescue> set prefix=(hdX,Y)/boot/grub<br />
grub rescue> insmod (hdX,Y)/boot/grub/normal.mod<br />
rescue:grub> normal<br />
<br />
=== Pager support ===<br />
<br />
GRUB2 supports pager for reading commands that provide long output (like the help command). This works only in normal shell mode and not in rescue mode. To enable pager, in GRUB2 command shell type:<br />
sh:grub> set pager=1<br />
<br />
== GUI configuration tools ==<br />
<br />
Following package may be installed from [[AUR]]<br />
* [https://aur.archlinux.org/packages.php?ID=44020 grub-customizer] (requires gettext gksu gtkmm hicolor-icon-theme openssl)<br />
*:Customize the bootloader (GRUB2 or BURG)<br />
* [http://kde-apps.org/content/show.php?content=139643 grub2-editor] (requires kdelibs)<br />
*:A KDE4 control module for configuring the GRUB2 bootloader<br />
* [http://kde-apps.org/content/show.php?content=137886 kcm-grub2] (requires kdelibs python2-qt kdebindings-python)<br />
*:This Kcm module manages the most common settings of Grub2.<br />
* [http://sourceforge.net/projects/startup-manager/ startupmanager] (requires gnome-python imagemagick yelp python2 xorg-xrandr)<br />
*:GUI app for changing the settings of GRUB, GRUB2, Usplash and Splashy<br />
<br />
== parttool or legacy hide/unhide ==<br />
<br />
If you have a win9x paradigm with hidden C disks GRUB Legacy had the hide/unhide feature. In GRUB2 this has been replaced by parttool. For example, to boot the third C disk of three win9x installations on the CLI enter the CLI and:<br />
parttool hd0,1 hidden+ boot-<br />
parttool hd0,2 hidden+ boot-<br />
parttool hd0,3 hidden- boot+<br />
set root=hd0,3<br />
chainloader +1<br />
boot<br />
<br />
== Using the rescue console ==<br />
<br />
See [[#Using the command shell]] first. If unable to activate the standard shell, one possible solution is to boot using a live CD or some other rescue disk to correct configuration errors and reinstall GRUB. However, such a boot disk is not always available (nor necessary); the rescue console is surprisingly robust.<br />
<br />
The available commands in GRUB rescue include {{ic|insmod}}, {{ic|ls}}, {{ic|set}}, and {{ic|unset}}. This example uses {{ic|set}} and {{ic|insmod}}. {{ic|set}} modifies variables and {{ic|insmod}} inserts new modules to add functionality.<br />
<br />
Before starting, the user must know the location of their {{ic|/boot}} partition (be it a separate partition, or a subdirectory under their root):<br />
grub rescue> set prefix=(hdX,Y)/boot/grub<br />
<br />
where X is the physical drive number and Y is the partition number.<br />
<br />
To expand console capabilities, insert the {{ic|linux}} module:<br />
grub rescue> insmod (hdX,Y)/boot/grub/linux.mod<br />
<br />
{{Note|With a separate boot partition, omit {{ic|/boot}} from the path, (i.e. type {{ic|1=set prefix=(hdX,Y)/grub}} and {{ic|insmod (hdX,Y)/grub/linux.mod}}).}}<br />
<br />
This introduces the {{ic|linux}} and {{ic|initrd}} commands, which should be familiar (see [[#Configuration]]).<br />
<br />
An example, booting Arch Linux:<br />
set root=(hd0,5)<br />
linux /boot/vmlinuz-linux root=/dev/sda5<br />
initrd /boot/initramfs-linux.img<br />
boot<br />
<br />
With a separate boot partition, again change the lines accordingly:<br />
set root=(hd0,5)<br />
linux /vmlinuz-linux root=/dev/sda6<br />
initrd /initramfs-linux.img<br />
boot<br />
<br />
After successfully booting the Arch Linux installation, users can correct {{ic|grub.cfg}} as needed and then reinstall GRUB2.<br />
<br />
to reinstall GRUB2 and fix the problem completely, changing {{ic|/dev/sda}} if needed. See [[#Bootloader installation]] for details.<br />
<br />
== Combining the use of UUID's and basic scripting ==<br />
<br />
If you like the idea of using UUID's to avoid unreliable BIOS mappings or are struggling with GRUB's syntax, here is an example boot menu item that uses UUID's and a small script to direct GRUB to the proper disk partitions for your system. All you need to do is replace the UUID's in the sample with the correct UUID's for your system. The example applies to a system with a boot and root partition. You will obviously need to modify the GRUB configuration if you have additional partitions:<br />
<br />
menuentry "Arch Linux 64" {<br />
# Set the UUIDs for your boot and root partition respectively<br />
set the_boot_uuid=ece0448f-bb08-486d-9864-ac3271bd8d07 <br />
set the_root_uuid=c55da16f-e2af-4603-9e0b-03f5f565ec4a<br />
<br />
# (Note: This may be the same as your boot partition)<br />
<br />
# Get the boot/root devices and set them in the root and grub_boot variables <br />
search --fs-uuid --no-floppy --set=root $the_root_uuid <br />
search --fs-uuid --no-floppy --set=grub_boot $the_boot_uuid<br />
<br />
# Check to see if boot and root are equal.<br />
# If they are, then append /boot to $grub_boot (Since $grub_boot is actually the root partition)<br />
if [ $the_boot_uuid == $the_root_uuid] ; then<br />
set grub_boot=$grub_boot/boot<br />
fi<br />
<br />
# $grub_boot now points to the correct location, so the following will properly find the kernel and initrd<br />
linux ($grub_boot)/vmlinuz-linux root=/dev/disk/by-uuid/$uuid_os_root ro<br />
initrd ($grub_boot)/initramfs-linux.img<br />
}<br />
<br />
== Troubleshooting ==<br />
<br />
Any troubleshooting should be added here.<br />
<br />
=== Enable GRUB2 debug messages ===<br />
<br />
Add:<br />
<br />
set pager=1<br />
set debug=all<br />
<br />
to {{ic|grub.cfg}}.<br />
<br />
=== Correct GRUB2 No Suitable Mode Found Error ===<br />
<br />
If you get this error when booting any menuentry:<br />
<br />
error: no suitable mode found<br />
Booting however<br />
<br />
Then you need to initialize GRUB2 graphical terminal (gfxterm) with proper video mode (gfxmode) in GRUB2. This video mode is passed by GRUB2 to the linux kernel via 'gfxpayload'. In case of UEFI systems, if the GRUB2 video mode is not initialized, no kernel boot messages will be shown in the terminal (atleast until KMS kicks in)<br />
<br />
Copy {{ic|/usr/share/grub/unicode.pf2}} to ${GRUB2_PREFIX_DIR} ({{ic|/boot/grub/}} in case of BIOS and UEFI systems. If GRUB2 UEFI was installed with {{ic|1=--boot-directory=/boot/efi/efi}} set, then the directory is {{ic|/boot/efi/efi/grub/}}:<br />
<br />
# cp /usr/share/grub/unicode.pf2 ${GRUB2_PREFIX_DIR}<br />
<br />
If {{ic|/usr/share/grub/unicode.pf2}} does not exist, install {{Pkg|bdf-unifont}}, create the {{ic|unifont.pf2}} file and then copy it to ${GRUB2_PREFIX_DIR}:<br />
<br />
# grub-mkfont -o unicode.pf2 /usr/share/fonts/misc/unifont.bdf<br />
<br />
Then, in the {{ic|grub.cfg}} file, add the following lines to enable GRUB2 to pass the video mode correctly to the kernel, without of which you will only get a black screen (no output) but booting (actually) proceeds successfully without any system hang.<br />
<br />
BIOS systems:<br />
<br />
insmod vbe<br />
<br />
UEFI systems:<br />
<br />
insmod efi_gop<br />
insmod efi_uga<br />
<br />
After that add the following code (common to both BIOS and UEFI):<br />
<br />
insmod font<br />
<br />
if loadfont ${prefix}/fonts/unicode.pf2<br />
then<br />
insmod gfxterm<br />
set gfxmode=auto<br />
set gfxpayload=keep<br />
terminal_output gfxterm<br />
fi<br />
<br />
As you can see for gfxterm (graphical terminal) to function properly, {{ic|unicode.pf2}} font file should exist in ${GRUB2_PREFIX_DIR}.<br />
<br />
=== msdos-style error message ===<br />
<br />
grub-setup: warn: This msdos-style partition label has no post-MBR gap; embedding won't be possible!<br />
grub-setup: warn: Embedding is not possible. GRUB can only be installed in this setup by using blocklists.<br />
However, blocklists are UNRELIABLE and its use is discouraged.<br />
grub-setup: error: If you really want blocklists, use --force.<br />
<br />
This error may occur when you try installing GRUB2 in a VMware container. Read more about it [http://bbs.archlinux.org/viewtopic.php?pid=581760#p581760 here]. It happens when the first partition starts just after the MBR (block 63), without the usual space of 1 MiB (2048 blocks) before the first partition. Read [[#MBR_aka_msdos_partitioning_specific_instructions]]<br />
<br />
=== UEFI GRUB2 drops to shell ===<br />
<br />
If grub loads but drop you into the rescue shell with no errors, it may be because of a missing or misplaced {{ic|grub.cfg}}. This will happen if GRUB2 UEFI was installed with {{ic|--boot-directory}} and {{ic|grub.cfg}} is missing OR if the partition number of the boot partition changed (which is hard-coded into the {{ic|grubx64.efi}} file).<br />
<br />
=== UEFI GRUB2 not loaded ===<br />
In some cases the EFI may fail to load GRUB correctly. Provided everything is set up correctly, the output of:<br />
efibootmgr -v<br />
might look something like this:<br />
BootCurrent: 0000<br />
Timeout: 3 seconds<br />
BootOrder: 0000,0001,0002<br />
Boot0000* Grub HD(1,800,32000,23532fbb-1bfa-4e46-851a-b494bfe9478c)File(\efi\grub\grub.efi)<br />
Boot0001* Shell HD(1,800,32000,23532fbb-1bfa-4e46-851a-b494bfe9478c)File(\EfiShell.efi)<br />
Boot0002* Festplatte BIOS(2,0,00)P0: SAMSUNG HD204UI<br />
If everything works correctly, the EFI would now automatically load grub.<br><br />
If the screen only goes black for a second and the next boot option is tried afterwards, according to [https://bbs.archlinux.org/viewtopic.php?pid=981560#p981560 this post], moving grub to the partition root can help. The boot option has to be deleted and recreated afterwards. The entry for grub should look like this then:<br />
Boot0000* Grub HD(1,800,32000,23532fbb-1bfa-4e46-851a-b494bfe9478c)File(\grub.efi)<br />
<br />
=== Invalid signature ===<br />
If trying to boot windows results in an "invalid signature" error, e.g. after reconfiguring partitions or adding additional hard drives, (re)move grub's device configuration and let it reconfigure:<br />
# mv /boot/grub/device.map /boot/grub/device.map-old<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
{{ic|grub-mkconfig}} should now mention all found boot options including windows. If it works, remove {{ic|/boot/grub/device.map-old}}.<br />
<br />
== References ==<br />
<br />
# Official GRUB2 Manual - http://www.gnu.org/software/grub/manual/grub.html<br />
# Ubuntu wiki page for Grub2 - https://help.ubuntu.com/community/Grub2<br />
# GRUB2 wiki page describing steps to compile for UEFI systems - https://help.ubuntu.com/community/UEFIBooting<br />
# Wikipedia's page on [http://en.wikipedia.org/wiki/BIOS_Boot_partition BIOS Boot Partition]<br />
<br />
== External Links ==<br />
<br />
# [https://github.com/the-ridikulus-rat/My_Shell_Scripts/blob/master/grub/grub_bios.sh A Linux Bash Shell script to compile and install GRUB2 for BIOS from BZR Source]<br />
# [https://github.com/the-ridikulus-rat/My_Shell_Scripts/blob/master/grub/grub_uefi.sh A Linux Bash Shell script to compile and install GRUB2 for UEFI from BZR Source]</div>SYSMANhttps://wiki.archlinux.org/index.php?title=Network_configuration&diff=163064Network configuration2011-09-30T14:15:12Z<p>SYSMAN: /* Set the hostname */ IP -> IP address</p>
<hr />
<div>[[Category:Networking (English)]]<br />
[[Category:Getting and installing Arch (English)]]<br />
{{i18n|Configuring Network}}<br />
{{Article summary start}}<br />
{{Article summary text|A simple guide for setting up and troubleshooting network.}}<br />
{{Article summary heading|Overview}}<br />
{{Article summary text|{{Networking overview}}}}<br />
{{Article summary end}}<br />
<br />
==Check first==<br />
Many times, the basic installation procedure has created a working network configuration. To check if this is so, use the following command:<br />
{{command| ping -c 3 www.google.com|<nowiki><br />
PING www.l.google.com (74.125.224.146) 56(84) bytes of data.<br />
64 bytes from 74.125.224.146: icmp_req=1 ttl=50 time=437 ms<br />
64 bytes from 74.125.224.146: icmp_req=2 ttl=50 time=385 ms<br />
64 bytes from 74.125.224.146: icmp_req=3 ttl=50 time=298 ms<br />
<br />
--- www.l.google.com ping statistics ---<br />
3 packets transmitted, 3 received, 0% packet loss, time 1999ms<br />
rtt min/avg/max/mdev = 298.107/373.642/437.202/57.415 ms<br />
</nowiki>|prompt=$}}<br />
{{Tip| The {{codeline|-c 3}} options instruct {{codeline|ping}} to do so three times. See {{codeline|man ping}} for more information.}}<br />
<br />
If it works, then you may only wish to personalize your settings from the options below.<br />
<br />
==Set the hostname==<br />
A hostname is a unique name created to identify a machine on a network. With Arch Linux, a machine's hostname is set in {{Filename|/etc/[[rc.conf]]}} or until a restart using the ''hostname'' command.<br />
Hostnames are restricted to alphanumeric characters. The dash ({{Codeline|-}}) can be used but a hostname cannot start or end with it. Length is restricted to 63 characters.<br />
<br />
Edit {{Filename|/etc/rc.conf}} and set HOSTNAME (archlinux in this example):<br />
HOSTNAME="archlinux"<br />
<br />
After setting a hostname, it is also a good idea to include the same name in {{Filename|/etc/hosts}}. This will help processes that refer to the computer by its hostname to find its IP address.<br />
<br />
Edit {{Filename|/etc/hosts}} and add the same HOSTNAME you entered in {{Filename|/etc/rc.conf}}:<br />
127.0.0.1 archlinux.domain.org localhost.localdomain localhost archlinux<br />
<br />
To set the hostname temporarily (until the next reboot) use the {{codeline|hostname}} command as root:<br />
{{cli|# hostname archlinux}}<br />
<br />
==Load the device module==<br />
Udev should detect your network card (NIC) module and load it automatically at startup. If it does, skip this section. Otherwise, you will need to know which module is needed for your particular model:<br />
{{cli|# hwdetect --show-net}}<br />
<br />
Once you recognize which module to use, you can load it with:<br />
{{cli|# modprobe ''<modulename>''}}<br />
<br />
If [[udev]] is not detecting and loading the proper module automatically during bootup, you can add it into the '''MODULES=''' array in {{codeline|/etc/rc.conf}}, so you do not need to "modprobe" it everytime you boot. For example, if tg3 is the network module:<br />
MODULES=(... !usbserial tg3 snd-cmipci ...)<br />
<br />
Other common modules are 8139too for cards with the Realtek chipset or sis900 for SiS cards.<br />
<br />
==Configure IP==<br />
It is important to realize that you may have a dynamically-assigned address using DHCP, or an unchanging and set "static" address.<br />
{{Note|For motherboards that have integrated NICs it is important to know which one is considered the primary (i.e. eth0) and which is considered the secondary (i.e. eth1) NIC. Many configuration issues are caused by users incorrectly configuring eth0 in their /etc/rc.conf when in fact, they have their eth1 plugged into the LAN!}}<br />
<br />
===For DHCP IP===<br />
For this option, you need the '''dhcpcd''' package (already available on most installations). To make use of it, edit {{filename|/etc/rc.conf}} like this:<br />
<br />
interface="eth0"<br />
address=<br />
netmask=<br />
gateway=<br />
<br />
Only the interface has to be defined, as leaving the other options blank will set network to DHCP.<br />
<br />
If you use DHCP and you do '''not''' want your DNS servers automatically assigned every time you start your network, be sure to add the following to the last section of {{filename|/etc/dhcpcd.conf}}:<br />
nohook resolv.conf<br />
<br />
Then add your own DNS nameserver to {{filename|/etc/resolv.conf}}.<br />
<br />
Make sure to test your new settings by stopping and starting the {{filename|/etc/rc.d/network}} daemon, as opposed to bringing down your interface and starting dhcp manually. To restart the network daemon: <br />
{{cli|# /etc/rc.d/network restart}}<br />
<br />
You may use the {{Package Official|openresolv}} package if several different processes want to control resolv.conf (i.e. dhcpcd and VPN client). No additional configuration for dhcpcd is needed to use openresolv.<br />
<br />
{{Note|1=It is possible to have a static ip using dhcpcd. Simply edit your {{filename|/etc/conf.d/dhcpcd}} file to look something like this (where x.x.x.x is your desired ip):<br />
<pre><br />
DHCPCD_ARGS="-q -s x.x.x.x"<br />
</pre>}}<br />
<br />
===For Static IP===<br />
There are various reasons why you may wish to assign static IP addresses on your network. For instance, one may gain a certain degree of predictability, and a particular type of security benefit. Also, if you share your internet connection from a Windows box without a router, be sure to use static IPs on both computers. Otherwise you will have LAN issues.<br />
<br />
You need:<br />
* Your static IP address,<br />
* The netmask,<br />
* The broadcast address,<br />
* Your gateway,<br />
* Your nameservers' IP addresses,<br />
* Your domain name.<br />
<br />
If you are running a private network, it is safe to use IP addresses in 192.168.*.* for your IPs, with a netmask of 255.255.255.0 and broadcast address of 192.168.*.255. Unless your network has a router, the gateway address does not matter. Edit {{filename|/etc/rc.conf}} like this, substituting your own values for the IP, netmask, broadcast, and gateway:<br />
<br />
interface=eth0<br />
address=192.168.0.2<br />
netmask=255.255.255.0<br />
gateway=192.168.22.1<br />
<br />
Edit your {{filename|/etc/resolv.conf}} like this, substituting your nameservers' IPs and your domain name:<br />
nameserver 61.23.173.5<br />
nameserver 61.95.849.8<br />
search example.com<br />
<br />
{{Note|Currently you may include a maximum of 3 nameserver lines.}}<br />
<br />
====Manual assignment====<br />
You can assign a static IP in console:<br />
{{cli|# ip addr add <ip>/<netmask> dev <interface>}}<br />
For example:<br />
{{cli|# ip addr add 192.168.1.2/24 dev eth0}}<br />
For more options, see: {{codeline|man ip}}<br />
<br />
Add your gateway like so:<br />
{{cli|# ip route add default via <ip>}}<br />
(Substitute your own gateway IP)<br />
<br />
For example:<br />
{{cli|# ip route add default via 192.168.1.1}}<br />
<br />
==Load configuration==<br />
To test your settings either reboot the computer, or as root:<br />
{{cli|# /etc/rc.d/network restart}}<br />
<br />
Try pinging your gateway, DNS server, ISP provider and other Internet sites, in that order, to detect any connection problems along the way, as in this example:<br />
{{cli|$ ping -c 3 www.google.com}}<br />
<br />
==Additional settings==<br />
<br />
===Enable/disable interface===<br />
You can activate or deactivate net interface:<br />
{{cli|# ip link set <interface> up/down}}<br />
<br />
===Firewall===<br />
You can install and configure a [[Firewalls|firewall]] to feel more secure.<br />
<br />
===Wireless Setup===<br />
See the [[Wireless Setup]] article for more information.<br />
<br />
===Laptops, 'ifplugd'===<br />
You can install a daemon which will automatically configure your Ethernet device when a cable is plugged in and automatically unconfigure it if the cable is pulled. This is useful on laptops with onboard network adapters, since it will only configure the interface when a cable is really connected. Another use is when you just need to restart the network but do not want to restart the computer or do it from the shell.<br />
<br />
Installation is very simple since it is in [extra]:<br />
{{cli|# pacman -S ifplugd}}<br />
<br />
By default it is configured to work for {{codeline|eth0}} device. This and other settings like delays can be configured in {{filename|/etc/ifplugd/ifplugd.conf}}.<br />
<br />
[[Daemon#Performing daemon actions manually|Start the ifplugd daemon]] and add ifplugd to your [[Daemons#Starting on Boot|DAEMONS array]] so it starts automatically on boot.<br />
<br />
===Jumbo Frames===<br />
See the [[Jumbo Frames]] article for more information.<br />
<br />
===Bonding===<br />
You can install the {{codeline|ifenslave}} package to bind two real Ethernet cables with one IP address. After installation, you will need to edit each of the following files:<br />
<br />
{{filename|/etc/conf.d/bonding}}:<br />
bond_bond0="eth0 eth1"<br />
BOND_INTERFACES=(bond0)<br />
<br />
{{filename|/etc/modprobe.d/modprobe.conf}}:<br />
{{Note | The new {{codeline|module-init-tools}} 3.8 package changes the location of the configuration file: {{filename|/etc/modprobe.conf}} is no longer read, instead {{filename|/etc/modprobe.d/modprobe.conf}} is used. [http://www.archlinux.org/news/450/ link]}}<br />
options bonding miimon=100<br />
<br />
{{filename|/etc/rc.conf}}:<br />
MODULES=(... bonding ...)<br />
interface=bond0<br />
address=192.168.1.1<br />
netmask=255.255.255.0<br />
gateway=192.168.1.255<br />
<br />
To activate the new bonded ports, restart your network by:<br />
{{cli|# rc.d restart network}}<br />
<br />
===IP aliasing===<br />
{{Expansion}}<br />
If you want to use multiple IP adresses on an interface, you will have to use [[netcfg]] and its POST_UP and PRE_DOWN commands in your network profile to set up the additional IPs manually. See [https://bbs.archlinux.org/viewtopic.php?pid=951573#p951573 here] for details.<br />
<br />
====Example====<br />
You will need {{codeline|netcfg}}<br />
<br />
{{cli|# pacman -S netcfg}}<br />
<br />
Prepare configuration<br />
<br />
{{File<br />
|name=/etc/network.d/mynetwork<br />
|content=<nowiki><br />
<br />
# CONNECTION='ethernet'<br />
# DESCRIPTION='Five different addresses on the same NIC.'<br />
# INTERFACE='eth0'<br />
# IP='static'<br />
# ADDR='192.168.1.10'<br />
# GATEWAY='192.168.1.1'<br />
# DNS=('192.168.1.1')<br />
# DOMAIN=''<br />
# POST_UP='for i in 11 12 13 14 ; do ip addr add 192.168.1.$i/24 brd 192.168.1.255 dev eth0 ; done'<br />
# PRE_DOWN='for i in 11 12 13 14 ; do ip addr del 192.168.1.$i/24 dev eth0 ; done'<br />
<br />
</nowiki>}}<br />
<br />
{{File<br />
|name=/etc/rc.conf<br />
|content=<nowiki><br />
NETWORKS=(mynetwork)<br />
<br />
...<br />
<br />
DAEMONS=(... net-profiles ...)<br />
</nowiki>}}<br />
<br />
===Change MAC/hardware address===<br />
Changing your MAC address is not possible anymore via {{filename|/etc/rc.conf}}. See [[MAC Address Spoofing]] for details.<br />
<br />
==Troubleshooting==<br />
<br />
=== DHCP fails at boot ===<br />
First, check all the steps that the computer normally executes at boot in order to find out which one failed. <br />
These steps are:<br />
# Detect the network device and load its driver. <br />
# Bring up the interface. <br />
# Call {{codeline|dhcp}}<br />
<br />
====Step 1====<br />
Check the "Ethernet controller" entry in the output of {{codeline|lspci -v}}.<br />
It should tell you which kernel module contains the driver of your network device. For example:<br />
{{command|lspci -v|<nowiki><br />
02:00.0 Ethernet controller: Attansic Technology Corp. L1 Gigabit Ethernet Adapter (rev b0)<br />
...<br />
Kernel driver in use: atl1<br />
Kernel modules: atl1<br />
</nowiki>|prompt=$}}<br />
Next, check the the driver was loaded via ''dmesg | grep <module name>''. For example:<br />
$ dmesg |grep atl1<br />
...<br />
atl1 0000:02:00.0: eth0 link is up 100 Mbps full duplex<br />
<br />
====Step 2====<br />
Check the output of {{codeline|dmesg}} for the interface associated with your network device and bring it up via (as root) <br />
{{cli|# ip link set <interface> up}}<br />
<br />
Check the result with {{codeline|ip addr show dev eth0}}. For example:<br />
{{command|ip addr show dev eth0|<nowiki><br />
2: eth0: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc vboxnetflt state UP qlen 1000<br />
[...]<br />
</nowiki>|prompt=$}}<br />
<br />
====Step 3====<br />
To be on the safe side, start by releasing the lease of your interface with {{codeline|dhcpcd --release}}, then try to get a lease with {{codeline|dhcpcd}}. Refer to {{codeline| man dhcpcd}} for more information.<br />
<br />
If all goes well it will look like this:<br />
{{command|dhcpcd --release eth0|<nowiki><br />
dhcpcd: dhcpcd not running</nowiki>|prompt=#}}<br />
{{command|dhcpcd eth0|<nowiki><br />
dhcpcd: version 5.1.1 starting<br />
dhcpcd: eth0: broadcasting for a lease<br />
...<br />
dhcpcd: eth0: leased 192.168.1.70 for 86400 seconds<br />
</nowiki>|prompt=#}}<br />
<br />
And now {{codeline|ip addr show dev <interface>}} should show your inet address.<br />
<br />
Probably things will not work as described somewhere along these steps, or else the network would have started automatically at boot.<br />
<br />
If {{codeline|dhcp}} works using the steps above but not at boot, add the following to {{filename|/etc/rc.local}}:<br />
dhcpcd -k eth0 <br />
dhcpcd -nd eth0<br />
<br />
See http://bbs.archlinux.org/viewtopic.php?id=63940 for more information.<br />
<br />
For some people, the {{codeline|dhclient}} package (available in [extra]) works where {{codeline|dhcpcd}} fails.<br />
<br />
===Swapping computers on the cable modem===<br />
Most domestic cable ISPs (videotron for example) have the cable modem configured to recognise only one client PC, by the MAC address of its network interface. Once the cable modem has learnt the MAC address of the first PC or equipment that talks to it, it will not respond to another MAC address in any way. Thus if you swap one PC for another (or for a router), the new PC (or router) will not work with the cable modem, because the new PC (or router) has a different MAC address to the old one. To reset the cable modem so that it will recognise the new PC, you must power the cable modem off and on again. Once the cable modem has rebooted and gone fully online again (indicator lights settled down), reboot the newly connected PC so that it makes a DHCP request, or manually make it request a new DHCP lease.<br />
<br />
If this method does not work, you will need to clone the MAC address of the original machine. See also [[Configuring Network#Change MAC/hardware address|Change MAC/hardware address]].<br />
<br />
===The TCP window scaling issue===<br />
TCP packets contain a "window" value in their headers indicating how much data the other host may send in return. This value is represented with only 16 bits, hence the window size is at most 64Kb. TCP packets are cached for a while (they have to be reordered), and as memory is (or used to be) limited, one host could easily run out of it.<br />
<br />
Back in 1992, as more and more memory became available, [http://www.faqs.org/rfcs/rfc1323.html RFC 1323] was written to improve the situation: Window Scaling. The "window" value, provided in all packets, will be modified by a Scale Factor defined once, at the very beginning of the connection.<br />
<br />
That 8-bit Scale Factor allows the Window to be up to 32 times higher than the initial 64Kb.<br />
<br />
It appears that some broken routers and firewalls on the Internet are rewriting the Scale Factor to 0 which causes misunderstandings between hosts.<br />
<br />
The Linux kernel 2.6.17 introduced a new calculation scheme generating higher Scale Factors, virtually making the aftermaths of the broken routers and firewalls more visible. <br />
<br />
The resulting connection is at best very slow or broken.<br />
<br />
====How to diagnose the problem====<br />
First of all, lets make it clear: this problem is odd. In some cases, you will not be able to use TCP connections (HTTP, FTP, ...) at all and in others, you will be able to communicate with some hosts (very few).<br />
<br />
When you have this problem, the <code>dmesg</code>'s output is OK, logs are clean and <code>ip addr</code> will report normal status &mdash; and actually everything appears normal.<br />
<br />
If you can not browse any website, but you can ping some rare hosts, chances are great that you're experiencing this issue: ping uses the ICMP protocol and is not affected by TCP issues.<br />
<br />
You can try to use Wireshark. You might see successful UDP and ICMP communications but unsuccessful TCP communications (only to foreign hosts).<br />
<br />
====How to fix it (The bad way)====<br />
To fix it the bad way, you can change the tcp_rmem value, on which Scale Factor calculation is based. Although it should work for most hosts, it is not guaranteed, especially for very distant ones.<br />
<br />
echo "4096 87380 174760" > /proc/sys/net/ipv4/tcp_rmem<br />
<br />
====How to fix it (The good way)====<br />
Simply disable Window Scaling. Since Window Scaling is a nice TCP feature, it may be uncomfortable to disable it, especially if you cannot fix the broken router. There are several ways to disable Window Scaling, and it seems that the most bulletproof way (which will work with most kernels) is to add the following line to {{Filename|/etc/sysctl.conf}} (see also [[sysctl]])<br />
<br />
net.ipv4.tcp_window_scaling = 0<br />
<br />
====How to fix it (The best way)====<br />
This issue is caused by broken routers/firewalls, so lets change them. Some users have reported that the broken router was their very own DSL router.<br />
<br />
====More about it====<br />
This section is based on the LWN article [http://lwn.net/Articles/92727/ TCP window scaling and broken routers] and a Kernel Trap article: [http://kerneltrap.org/node/6723 Window Scaling on the Internet].<br />
<br />
There are also several relevant threads on the LKML.<br />
<br />
=== Interface names varying ===<br />
<br />
Your network cards are sometimes named differently between two reboot. Configuring your network connection is hard if you do not know if your card will be called {{Codeline|eth0}} or {{Codeline|eth1}}.<br />
<br />
It is possible to specify the module loading order in {{Filename|/etc/rc.conf}}, but of course this only works if the kernel does not include the drivers as built-in AND if different network cards are in use (i.e. rely on different drivers)<br />
# Always load 8139too before e100<br />
MODULES=(8139too e100)<br />
<br />
'''-OR-'''<br />
<br />
With {{Codeline|ifrename}}, see [[Rename network interfaces]]<br />
<br />
'''-OR-'''<br />
<br />
It is also possible to manually create udev rules that assign interface names based on the interface's MAC address.<br />
<br />
{{File|name=/etc/udev/rules.d/10-network.rules|content=<nowiki><br />
SUBSYSTEM=="net", ATTR{address}=="aa:bb:cc:dd:ee:ff", NAME="lan0"<br />
SUBSYSTEM=="net", ATTR{address}=="ff:ee:dd:cc:bb:aa", NAME="wlan0"<br />
</nowiki>}}<br />
<br />
For more information or the original udev guide on the last two methods, see the [[Udev]] wiki entry on this issue.<br />
<br />
[[Udev#Mixed Up Devices, Sound/Network Cards Changing Order Each Boot]]<br />
<br />
===Realtek no link / WOL issue===<br />
Users with Realtek 8168 8169 8101 8111(C) based NICs (cards / and on-board) may notice an issue where the NIC seems to be disabled on boot and has no Link light. This can usually be found on a dual boot system where Windows is also installed. It seems that using the offical Realtek drivers (dated anything after May 2007) under Windows is the cause. These newer drivers disable the Wake-On-LAN feature by disabling the NIC at Windows shutdown time, where it will remain disabled until the next time Windows boots. You will be able to notice if this issue is affecting you if the Link light remains off until Windows boots up; during Windows shutdown the Link light will switch off. Normal operation should be that the link light is always on as long as the system is on, even during POST. This issue will also affect other operative systems without newer drivers (eg. Live CDs). Here are a few fixes for this issue:<br />
<br />
====Method 1 - Rollback/change Windows driver====<br />
You can roll back your Windows NIC driver to the Microsoft provided one (if available), or roll back/install an official Realtek driver pre-dating May 2007 (may be on the CD that came with your hardware).<br />
<br />
====Method 2 - Enable WOL in Windows driver====<br />
Probably the best and the fastest fix is to change this setting in the Windows driver. This way it should be fixed system-wide and not only under Arch (eg. live CDs, other operative systems). In Windows, under Device Manager, find your Realtek network adapter and double-click it. Under the Advanced tab, change "Wake-on-LAN after shutdown" to Enable.<br />
In Windows XP (example)<br />
Right click my computer<br />
--> Hardware tab<br />
--> Device Manager<br />
--> Network Adapters<br />
--> "double click" Realtek ...<br />
--> Advanced tab<br />
--> Wake-On-Lan After Shutdown<br />
--> Enable<br />
<br />
{{Note|Newer Realtek Windows drivers (tested with ''Realtek 8111/8169 LAN Driver v5.708.1030.2008'', dated 2009/01/22, available from GIGABYTE) may refer to this option slightly differently, like ''Shutdown Wake-On-LAN --> Enable''. It seems that switching it to {{Codeline|Disable}} has no effect (you will notice the Link light still turns off upon Windows shutdown). One rather dirty workaround is to boot to Windows and just reset the system (perform an ungraceful restart/shutdown) thus not giving the Windows driver a chance to disable LAN. The Link light will remain on and the LAN adapter will remain accessible after POST - that is until you boot back to Windows and shut it down properly again.}}<br />
<br />
====Method 3 - Newer Realtek Linux driver====<br />
Any newer driver for these Realtek cards can be found for Linux on the realtek site. (untested but believed to also solve the problem).<br />
<br />
====Method 4 - Enable ''LAN Boot ROM'' in BIOS/CMOS====<br />
It appears that setting ''Integrated Peripherals --> Onboard LAN Boot ROM --> Enabled'' in BIOS/CMOS reactivates the Realtek LAN chip on system boot-up, despite the Windows driver disabling it on OS shutdown.<br />
<br><small>This was tested successfully multiple times with GIGABYTE system board GA-G31M-ES2L with BIOS version F8 released on 2009/02/05. YMMV.</small><br />
<br />
===DLink G604T/DLink G502T DNS issue===<br />
Users with a DLink G604T/DLink G502T router, using DHCP and have firmware v2.00+ (typically users with AUS firmware) may have issues with certain programs not resolving the DNS. One of these programs are unfortunatley pacman. The problem is basically the router in certain situations is not sending the DNS properly to DHCP, which causes programs to try and connect to servers with an IP of 1.0.0.0 and fail with a connection timed out error<br />
<br />
====How to diagnose the problem====<br />
The best way to diagnose the problem is to use Firefox/Konqueror/links/seamonkey and to enable wget for pacman. If this is a fresh install of Arch Linux, then you may want to consider installing {{Codeline|links}} through the live CD.<br />
<br />
Firstly enable wget for pacman (since it gives us info about pacman when its downloading packages)<br />
Open {{Filename|/etc/pacman.conf}} with your favourite editor and uncomment the following line (remove the # if its there)<br />
<br />
XferCommand=/usr/bin/wget --passive-ftp -c -O %o %u<br />
<br />
While you are editing {{Filename|/etc/pacman.conf}}, check the default mirror that pacman uses to download packages.<br />
<br />
Now open up the default mirror in an Internet browser to see if the mirror actually works. If it does work, then do {{Codeline|pacman -Syy}} (otherwise pick another working mirror and set it to the pacman default). If you get something similar to the following (notice the 1.0.0.0),<br />
<nowiki>ftp://mirror.pacific.net.au/linux/archlinux/extra/os/i686/extra.db.tar.gz</nowiki> <br />
<nowiki>=> `/var/lib/pacman/community.db.tar.gz.part'</nowiki><br />
Resolving mirror.pacific.net.au... 1.0.0.0<br />
then you most likely have this problem. The 1.0.0.0 means its unable to resolve DNS, so we must add it to {{Filename|/etc/resolv.conf}}.<br />
<br />
====How to fix It====<br />
Basically what we need to do is to manually add the DNS to our {{Filename|/etc/resolv.conf}} file, The problem is that DHCP automatically deletes and replaces this file on boot, so we need to edit {{Filename|/etc/conf.d/dhcpcd}} and change the flags to stop DHCP doing this<br />
<br />
When you open up {{Filename|/etc/conf.d/dhcpcd}}, you should see something close to the following<br />
DHCPCD_ARGS="-t 30 -h $HOSTNAME"<br />
add the -R flag to the arguments, e.g.<br />
DHCPCD_ARGS="-R -t 30 -h $HOSTNAME"<br />
<br />
{{Note|1=If you are using dhcpcd >= 4.0.2 the -R flag has been deprecated. Please see the [[#For DHCP IP]] section for information on how to use a custom {{Filename|/etc/resolv.conf}} file.}}<br />
<br />
Save and close the file; now open {{Filename|/etc/resolv.conf}}. You should see a single namespace (most likely 10.1.1.1). This is the gateway to your router, which we need to connect to in order to get the DNS of your ISP. Paste the IP address into your browser and log in to your router. Go to the DNS section, and you should see an IP address in the Preferred DNS Server, copy it and paste it as a namespace ABOVE the current gateway one.<br />
<br />
E.g. a {{Filename|/etc/resolv.conf}} should look something along the lines of<br />
namespace 10.1.1.1<br />
<br />
If my Primary DNS Server is 211.29.132.12, then change {{Filename|/etc/resolv.conf}} to<br />
namespace 211.29.132.12<br />
namespace 10.1.1.1<br />
<br />
Now restart the network daemon by doing {{Codeline|/etc/rc.d/network restart}} and do {{Codeline|pacman -Syy}}. If it syncs correctly with the server, then the problem is solved.<br />
<br />
====More about it====<br />
This is the whirlpool forum (Australian ISP community) which talks about and gives the same solution to the problem<br />
http://forums.whirlpool.net.au/forum-replies-archive.cfm/461625.html<br />
<br />
===Get an IP from the wrong DHCP in linked (by VPN) router cases===<br />
In my case, I have a network where two routers are tied together through VPN. I have one router at my home, and one at a completely different place in the world. In some rare cases, it it appears that the router that is connected to me by VPN is assigning me an IP address. I don't know a way to prevent that process, but I do know a way to fix it. On a console, as root, try this:<br />
dhcpcd -k<br />
dhcpcd<br />
The first line releases your IP and the next line requests a new one. I had to run those two commands three times till my issue was fixed, so don't expect it to work after just one try. If that also fails you might need to disconnect the VPN connection and try it again with the commands above.<br />
<br />
This even works when NetworkManager is installed.<br />
<br />
===Realtek 8111E loses lots of packets/dmesg is flooded with link messages===<br />
This issue currently plagues rev6 of the 8111. To check if you have this chip, check the output of the following:<br />
lspci | grep 8111<br />
<br />
If you see a line like the following:<br />
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06)<br />
and dmesg has a bunch of this:<br />
r8169 0000:03:00.0: eth0: link up<br />
You are using a bad r8169 driver. To fix this, install the {{Codeline|r8168}} package from the AUR, blacklist the r8169 driver in {{Filename|/etc/modprobe.d/modprobe.conf}}, and reboot in order to fix the issue.<br />
Supposedly there is a fix for this in Linux 3.0<br />
<br />
Source: http://forums.gentoo.org/viewtopic-t-881217-start-0.html<br />
<br />
==Related==<br />
[[Samba]]</div>SYSMANhttps://wiki.archlinux.org/index.php?title=Laptop&diff=162822Laptop2011-09-29T09:28:22Z<p>SYSMAN: /* TLP for Thinkpads */ typo corrected</p>
<hr />
<div>[[Category:Laptops (English)]]<br />
{{i18n|Laptop}}<br />
== Setting Up For Laptops ==<br />
This page should contain links to pages needed for configuring a laptop for the best experience. Setting up a laptop is in many ways the same as setting up a desktop. However, there are a few key differences. When setting up a laptop with Arch Linux, the following points should be taken into consideration:<br />
<br />
* Power consumption (how do I make the battery last the longest per charge?). Which leads to power management:<br />
* Hard drive spindown. After how many minutes of inactivity should the hard drive be spun down?<br />
* Screen shut off. After how many minutes of inactivity should the screen be shut off? (Not just blanked with a screensaver but completely shut off).<br />
* CPU frequency scaling. How should the CPU's frequency change depending on load to minimize power usage?<br />
* Suspend and hibernate. How do I get suspend and hibernate to work with my laptop?<br />
* Screen brightness. How do I manage screen brightness?<br />
<br />
* Network and wireless. How do I get my wireless working?<br />
* Media buttons. How do I configure the function of those buttons on my laptop?<br />
* Touchpad. How do I configure the sensitivity, acceleration, button function and scroll borders for my Synaptics or Alps touchpad?<br />
<br />
All of these points are important to take into consideration when getting a laptop set up the way you like. Fortunately, Arch Linux provides all the tools and programs necessary to take complete control of your laptop. These programs and utilities are highlighted below, with appropriate tips tutorials.<br />
<br />
<br />
Note: the following links may be useful:<br />
<br />
* [http://www.linux-on-laptops.com/ http://www.linux-on-laptops.com/]<br />
* [http://www.linlap.com/ http://www.linlap.com/]<br />
<br />
== Power Management ==<br />
Power management is very important for anyone who wishes to make good use of their battery capacity. The following tools and programs help to increase battery life and keep your laptop cool and quiet.<br />
<br />
=== Battery State Monitoring Utilities ===<br />
<br />
Battery state can of course be read with acpi from the terminal. Acpi can be installed with<br />
<br />
{{Cli|# pacman -S acpi}}<br />
<br />
{{Tip| More information can be found for [[ACPI modules]]}}<br />
<br />
A simple battery monitor that sits in the system tray is [http://aur.archlinux.org/packages.php?ID=24694 batterymon] which can be found in the [[AUR]].<br />
<br />
=== Battery Tweaks on Thinkpad ===<br />
<br />
Please read the [[tp_smapi]] article.<br />
<br />
=== TLP for Thinkpads ===<br />
[[TLP]] is a set of scripts, which set many powersaving options according to the current Powersource. [[TLP]] is intended to be used on Thinkpads, but most settings should work on other laptops too.<br />
<br />
=== Cpufrequtils ===<br />
<br />
[[Cpufrequtils]] provides CPU Frequency Scaling, a technology used primarily by notebooks which enables the OS to scale the CPU speed up or down, depending on the current system load and/or power scheme. For quick and easy installation and setup, please view the [[CPU Frequency Scaling]] article.<br />
<br />
=== Pm-utils ===<br />
[[Pm-utils]] provides a suspend and powerstate setting framework. Pm-utils should be used with cpufrequtils to provide a complete power management solution.<br />
<br />
=== Lapsus ===<br />
[[Asus_G1#The_Lapsus_daemon_.26_KDE_applet|Lapsus]] is a set of programs providing easy access to many features of various laptops. It currently supports most features provided by asus-laptop kernel module from ACPI4Asus project, such as additional LEDs, hotkeys, backlight control etc. It also has support for some IBM laptops features provided by IBM ThinkPad ACPI Extras Driver and NVRAM device.<br />
<br />
=== Install PowerTOP ===<br />
[http://www.lesswatts.org/projects/powertop/ PowerTOP] is a handy utility from Intel that displays which hardware/processes are using the most power on your system, and provides instructions on how to stop or remove power-wasting services. Works great for mobile Intel CPUs; provides the current CPU state and suggestions for power saving. Also works on AMD systems, but does not provide as much information about the CPU state.<br />
<br />
See the [[Powertop]] article for informations.<br />
<br />
=== Laptop mode tools ===<br />
Install [[Laptop Mode Tools]] with:<br />
<br />
{{Cli|# pacman -S laptop-mode-tools}}<br />
<br />
* The configuration files can be found in {{Filename|/etc/laptop-mode/laptop-mode.conf}} and {{Filename|/etc/laptop-mode/conf.d/*}}<br />
{{Tip| Be sure to go through these config files, as many power-saving features are not enabled by default.}}<br />
[[Daemon#Performing daemon actions manually|Start the laptop-mode daemon]] and add laptop-mode to your [[Daemons#Starting on Boot|DAEMONS array]] so it starts automatically on boot.<br />
<br />
See [http://bbs.archlinux.org/viewtopic.php?id=39258 this thread] for more information.<br />
<br />
=== Powernowd ===<br />
[[Powernowd]] is a program for powering down CPUs dynamically, which can be run either on an AMD-based system or an Intel-based system. However, cpufrequtils detailed above provides a more modern alternative, as seen by the fact that powernowd was created before the ondemand governor existed.<br />
<br />
You can install [http://aur.archlinux.org/packages.php?ID=14233 powernowd] from the [[AUR]].<br />
<br />
To configure it, just edit your {{Filename|/etc/conf.d/powernowd}}:<br />
OPTIONS="-q -u 15 -l 5"<br />
<br />
=== PCI-e ASPM ===<br />
On some laptops, powertop suggests enabling the CONFIG_PCIEASPM kernel option. It can be found under "Bus options (PCI etc.)"->"PCI Express ASPM support". This option is marked as experimental in the current kernel (2.6.35) and allows the PCI-e links to enter a power saving state. <br />
<br />
According to [http://www.lesswatts.org/projects/devices-power-management/pcie.php], this option might degrade performance a bit, but on an Acer 3820TG laptop, it can reduce power consumption by about one third or even more.<br />
<br />
More experience with this setting would be appreciated, so please share them [https://bbs.archlinux.org/viewtopic.php?id=107173 here]!<br />
<br />
It seems like the option is going to be enabled by default in kernel 2.6.36; if so, the information here will be obsolete soon. However, if your system should be able to make use of this power management feature but you are receiving messages like like the following (check {{Filename|/var/log/everything.log*}}):<br />
<br />
disabling ASPM on pre-1.1 PCI-e device. You can enable it with 'pcie_aspm=force'<br />
<br />
then add <code>pcie_aspm=force</code> to your kernel command line.<br />
<br />
===Granola===<br />
[http://aur.archlinux.org/packages.php?ID=36841 Granola] is a daemon that monitors the cpu usage and uses the cpufreq-userspace module to lessen power usage without any noticeable difference in performance.<br />
To use it, first install from the AUR:[http://aur.archlinux.org/packages.php?ID=36841], the default settings will work for most setups.<br />
You will need to load the cpufreq_userspace module, as well as the cpufreq scaling governor for your CPU at startup.<br />
Edit {{Filename|/etc/rc.conf}}:<br />
For most generic cpus:<br />
<br />
MODULES=( ... cpufreq_userspace acpi-cpufreq ... )<br />
<br />
For Intel Atom or Pentium 4 cpus:<br />
<br />
MODULES=( ... cpufreq_userspace p4_clockmod ... )<br />
<br />
Then add Granola to the DAEMONS array:<br />
<br />
DAEMONS=( ... granola ... )<br />
<br />
and reboot. <br />
<br />
To test if it worked, run:<br />
<br />
cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq<br />
#OR<br />
cpufreq-info #if you have cpufreq-utils installed<br />
<br />
and check that the cpu frequency is below maximum.<br />
<br />
=== Suggestions for saving power ===<br />
<br />
==== WLAN-device ====<br />
When often en route working with your Notebook without WLAN-Access around, it might be expedient to add a little script to your system startup that automatically turns off your WLAN-Hardware to keep it from searching for Access Points and wasting power on this, when not connected:<br />
<br />
#!/bin/bash<br />
<br />
essid="`iwconfig wlan0 | grep ESSID | awk {'print $4'}`"<br />
if [ "$essid" == "ESSID:off/any" ] ; then<br />
sudo iwconfig wlan0 txpower off<br />
fi<br />
[edit, if wlan0 ain't your WLAN-device]<br />
<br />
Start the script according to your DE/WM options by '(sleep xx && /path/to/script)' depending on how long it usually takes to connect to your Access Point, 60 seconds are a good default value. It will check if you're connected, turning off the device if not.<br />
sudo iwconfig wlan0 txpower on<br />
will bring it back up, as, of course, a reboot will.<br />
<br />
==== Others ====<br />
{{Note|Not only are the following tweaks not needed if using laptop-mode-tools, but using laptopmode also gives you the benefit of applying them only when desired (ie, while the AC cable is unplugged).}}<br />
===== Disk-related tweaks =====<br />
Disable file access time: every time you access (read) a file the filesystem writes an access time to the file metadata. You can disable this on individual files by using the chattr command, or you can enable it on an entire disk by setting the ''noatime'' option in your fstab, as follows:<br />
<br />
/dev/sda1 / ext3 defaults,noatime 1 2<br />
<br />
[http://www.faqs.org/docs/securing/chap6sec73.html Source]<br />
<br />
:''Note'': disabling atime causes troubles with [[Mutt|mutt]] and other applications that make use of file timestamps. Consider compromising between performance and compatibility by using mount option relatime instead, or look into [http://wiki.mutt.org/?MaildirFormat mutt work-around for noatime].<br />
<br />
To allow the CD/DVD rom to spin down after a while, run the following: <br />
<br />
/usr/bin/hal-disable-polling --device /dev/scd0<br />
<br />
Note, however, that [[HAL]] has long been deprecated.<br />
<br />
===== More tweaks =====<br />
These are some generic suggestions that will work with most laptops.<br />
<br />
Add the following to {{Filename|/etc/modprobe.d/modprobe.conf}}:<br />
<br />
options usbcore autosuspend=1<br />
<br />
Add the following to {{Filename|/etc/sysctl.conf}}<br />
<br />
vm.dirty_writeback_centisecs=1500<br />
vm.laptop_mode=5<br />
<br />
Add the following to {{Filename|/etc/rc.local}} (and make sure it gets executed at boot time)<br />
<br />
/usr/sbin/iwpriv your_wireless_interface set_power 5<br />
<br />
Source: [http://www.nervous.it/2007/11/linux-dell-xps-m1330/ here]<br />
<br />
===== Hard drive spin down problem =====<br />
Documented [https://bugs.launchpad.net/ubuntu/+source/acpi-support/+bug/59695 here]<br />
<br />
To prevent your laptop hard drive from spinning down too often (result of too aggressive APM defaults) do the following:<br />
<br />
Add the following to {{Filename|/etc/rc.local}}<br />
<br />
hdparm -B 254 /dev/sdX ''where X is your hard drive device''<br />
<br />
You can also set it to 255 to completely disable spinning down. You may wish to set a lower value if you move your laptop around as lower values park the heads more often and reduce the chance of damage to your hard disk while it is being moved. If you don't move your laptop at all when you are using it, then 255 or 254 is probably best. If you do, then you might want to try a lower value. A value like 128 might be a good middle-ground.<br />
<br />
Add the following to {{Filename|/etc/pm/sleep.d/50-hdparm_pm}}<br />
<br />
#!/bin/sh<br />
<br />
if [ -n "$1" ] && ([ "$1" = "resume" ] || [ "$1" = "thaw" ]); then<br />
hdparm -B 254 /dev/your-hard-drive > /dev/null<br />
fi<br />
<br />
and run ''chmod +x /etc/pm/sleep.d/50-hdparm_pm'' to make sure it resets after suspend. Again, you can change the value 254 as you see fit.<br />
<br />
Now the APM level should be set for your hard drive.<br />
<br />
For some laptops, the option -S to hdparm can also be relevant (sets the spindown time for the drive). Note that all these options can also be configured using the [[Laptop_Mode_Tools | laptop-mode tools]]. This will allow you to set a high value when on AC and a lower value when you are running on battery power.<br />
<br />
===== Tweaking the scheduler =====<br />
For multicore and hyperthreading-enabled processors you may use ''sched_mc_power_savings'' and ''sched_smt_power_savings'' options respectively to make the scheduler keep idle as many cores as possible. To enable these options you can do<br />
echo 1 > /sys/devices/system/cpu/sched_mc_power_savings<br />
or<br />
echo 1 > /sys/devices/system/cpu/sched_smt_power_savings<br />
Echoing 0 will disable them. Also laptop-mode can be used to control ''shed_mc_power_savings'' (see the appropriate config file in {{Filename|/etc/laptop-mode/conf.d}}).<br />
<br />
== Touchpad ==<br />
To get your touchpad working properly, see the [[Touchpad Synaptics]] page. Note that your laptop may have an ALPS touchpad (such as the DELL Inspiron 6000), and not a Synaptics touchpad. In either case, see the link above.<br />
<br />
== Special Buttons ==<br />
To configure any special keys or buttons on your laptop, please refer to the [[Extra Keyboard Keys]] page.<br />
<br />
== Hard disk shock protection ==<br />
There are several laptops from different vendors featuring shock protection capabilities. As manufacturers have refused to support open source development of the required software components so far, Linux support for shock protection varies considerably between different hardware implementations.<br />
<br />
Currently, two projects, named HDAPS and hpfall, support this kind of protection.<br />
HDAPS is for IBM/Lenovo Thinkpads and hpfall for HP/Compaq laptops<br />
<br />
Just Check [[HDAPS|Hard Disk Active Protection System]].<br />
Hpfall canbe installed from AUR https://aur.archlinux.org/packages.php?ID=45093</div>SYSMAN