https://wiki.archlinux.org/api.php?action=feedcontributions&user=TypicalTitan&feedformat=atomArchWiki - User contributions [en]2024-03-19T13:08:23ZUser contributionsMediaWiki 1.41.0https://wiki.archlinux.org/index.php?title=GRUB&diff=560855GRUB2018-12-29T23:47:47Z<p>TypicalTitan: /* LVM */ Work around for change in LVM</p>
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<div>[[Category:Boot loaders]]<br />
[[Category:GNU]]<br />
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{{Related articles start}}<br />
{{Related|Arch boot process}}<br />
{{Related|Master Boot Record}}<br />
{{Related|GUID Partition Table}}<br />
{{Related|Unified Extensible Firmware Interface}}<br />
{{Related|GRUB Legacy}}<br />
{{Related|GRUB/EFI examples}}<br />
{{Related|GRUB/Tips and tricks}}<br />
{{Related|Multiboot USB drive}}<br />
{{Related articles end}}<br />
[https://www.gnu.org/software/grub/ GRUB] (GRand Unified Bootloader) is a [[Boot loader|multi-boot loader]]. It is derived from [http://www.nongnu.org/pupa/ PUPA] which was a research project to develop the replacement of what is now known as [[GRUB Legacy]]. The latter had become too difficult to maintain and GRUB was rewritten from scratch with the aim to provide modularity and portability [https://www.gnu.org/software/grub/grub-faq.html#q1]. The current GRUB is also referred to as GRUB 2 while GRUB Legacy corresponds to versions 0.9x.<br />
<br />
{{Note|In the entire article {{ic|''esp''}} denotes the mountpoint of the [[EFI system partition]] aka ESP.}}<br />
<br />
== BIOS systems ==<br />
<br />
=== GUID Partition Table (GPT) specific instructions ===<br />
<br />
On a BIOS/[[GPT]] configuration, a [https://www.gnu.org/software/grub/manual/grub/html_node/BIOS-installation.html#BIOS-installation BIOS boot partition] is required. GRUB embeds its {{ic|core.img}} into this partition.<br />
<br />
{{Note|<br />
* Before attempting this method keep in mind that not all systems will be able to support this partitioning scheme. Read more on [[Partitioning#GUID Partition Table]].<br />
* The BIOS boot partition is only needed by GRUB on a BIOS/GPT setup. On a BIOS/MBR setup, GRUB uses the post-MBR gap for the embedding the {{ic|core.img}}. On GPT, however, there is no guaranteed unused space before the first partition.<br />
* For [[UEFI]] systems this extra partition is not required, since no embedding of boot sectors takes place in that case. However, UEFI systems still require an [[EFI system partition]].<br />
}}<br />
<br />
Create a mebibyte partition ({{ic|1=+1M}} with ''fdisk'' or ''gdisk'') on the disk with no file system and with partition type GUID {{ic|21686148-6449-6E6F-744E-656564454649}}.<br />
<br />
* Select partition type {{ic|BIOS boot}} for [[fdisk]].<br />
* Select partition type code {{ic|ef02}} for [[gdisk]].<br />
* For [[parted]] set/activate the flag {{ic|bios_grub}} on the partition.<br />
<br />
This partition can be in any position order but has to be on the first 2 TiB of the disk. This partition needs to be created before GRUB installation. When the partition is ready, install the bootloader as per the instructions below.<br />
<br />
The space before the first partition can also be used as the BIOS boot partition though it will be out of GPT alignment specification. Since the partition will not be regularly accessed performance issues can be disregarded, though some disk utilities will display a warning about it. In ''fdisk'' or ''gdisk'' create a new partition starting at sector 34 and spanning to 2047 and set the type. To have the viewable partitions begin at the base consider adding this partition last.<br />
<br />
=== Master Boot Record (MBR) specific instructions ===<br />
<br />
Usually the post-MBR gap (after the 512 byte [[MBR]] region and before the start of the first partition) in many MBR partitioned systems is 31 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 GRUB's {{ic|core.img}} ({{Bug|24103}}). It is advisable to use a partitioning tool that supports 1 MiB [[Partitioning#Partition alignment|partition alignment]] to obtain this space as well as to satisfy other non-512-byte-sector issues (which are unrelated to embedding of {{ic|core.img}}).<br />
<br />
=== Installation ===<br />
<br />
[[Install]] the {{Pkg|grub}} package. It will replace {{AUR|grub-legacy}}, where already installed. Then do:<br />
<br />
# grub-install --target=i386-pc /dev/sd'''X'''<br />
<br />
where {{ic|/dev/sd'''X'''}} is the disk where GRUB is to be installed (for example, disk {{ic|/dev/sda}} and '''not''' partition {{ic|/dev/sda1}}).<br />
<br />
Now you must [[#Generate the main configuration file]].<br />
<br />
If you use [[LVM]] for your {{ic|/boot}}, you can install GRUB on multiple physical disks.<br />
<br />
{{Tip|See [[GRUB/Tips and tricks#Alternative installation methods]] for other ways to install GRUB, such as to a USB stick.}}<br />
<br />
See {{man|8|grub-install}} and [https://www.gnu.org/software/grub/manual/grub/html_node/BIOS-installation.html#BIOS-installation GRUB Manual] for more details on the ''grub-install'' command.<br />
<br />
== UEFI systems ==<br />
<br />
{{Note|<br />
* It is recommended to read and understand the [[Unified Extensible Firmware Interface]], [[Partitioning#GUID Partition Table]] and [[Arch boot process#Under UEFI]] pages.<br />
* When installing to use UEFI it is important to boot the installation media in UEFI mode, otherwise ''efibootmgr'' will not be able to add the GRUB UEFI boot entry. Installing to the [[#Default/fallback boot path|fallback boot path]] will still work even in BIOS mode since it does not touch the NVRAM.<br />
* To boot from a disk using UEFI, an EFI system partition is required. Follow [[EFI system partition#Check for an existing partition]] to find out if you have one already, otherwise you need to create it.<br />
}}<br />
<br />
=== Installation ===<br />
<br />
{{Note|<br />
* UEFI firmwares are not implemented consistently across manufacturers. The procedure described below is intended to work on a wide range of UEFI systems but those experiencing problems despite applying this method are encouraged to share detailed information, and if possible the turnarounds found, for their hardware-specific case. A [[GRUB/EFI examples]] article has been provided for such cases.<br />
* The section assumes you are installing GRUB for x86_64 systems. For IA32 (32-bit) UEFI systems (not to be confused with 32-bit CPUs), replace {{ic|x86_64-efi}} with {{ic|i386-efi}} where appropriate.<br />
}}<br />
<br />
First, [[install]] the packages {{Pkg|grub}} and {{Pkg|efibootmgr}}: ''GRUB'' is the bootloader while ''efibootmgr'' is used by the GRUB installation script to write boot entries to NVRAM.<br />
<br />
Then follow the below steps to install GRUB:<br />
<br />
# [[EFI system partition#Mount the partition|Mount the EFI system partition]] and in the remainder of this section, substitute {{ic|''esp''}} with its mount point.<br />
# Choose a bootloader identifier, here named {{ic|GRUB}}. A directory of that name will be created in {{ic|''esp''/EFI/}} to store the EFI binary and this is the name that will appear in the UEFI boot menu to identify the GRUB boot entry.<br />
# Execute the following command to install the GRUB EFI application {{ic|grubx64.efi}} to {{ic|''esp''/EFI/GRUB/}} and install its modules to {{ic|/boot/grub/x86_64-efi/}}.<br />
<br />
# grub-install --target=x86_64-efi --efi-directory=''esp'' --bootloader-id=GRUB<br />
<br />
After the above install completed the main GRUB directory is located at {{ic|/boot/grub/}}. Note that {{ic|grub-install}} also tries to [[GRUB/Tips and tricks#Create a GRUB entry in the firmware boot manager|create an entry in the firmware boot manager]], named {{ic|GRUB}} in the above example.<br />
<br />
Remember to [[#Generate the main configuration file]] after finalizing the configuration.<br />
<br />
{{Tip|If you use the option {{ic|--removable}} then GRUB will be installed to {{ic|''esp''/EFI/BOOT/BOOTX64.EFI}} (or {{ic|''esp''/EFI/BOOT/BOOTIA32.EFI}} for the {{ic|i386-efi}} target) and you will have the additional ability of being able to boot from the drive in case EFI variables are reset or you move the drive to another computer. Usually you can do this by selecting the drive itself similar to how you would using BIOS. If dual booting with Windows, be aware Windows usually places an EFI executable there, but its only purpose is to recreate the UEFI boot entry for Windows.}}<br />
<br />
{{Note|<br />
* {{ic|--efi-directory}} and {{ic|--bootloader-id}} are specific to GRUB UEFI, {{ic|--efi-directory}} replaces {{ic|--root-directory}} which is deprecated. <br />
* You might note the absence of a ''device_path'' option (e.g.: {{ic|/dev/sda}}) in the {{ic|grub-install}} command. In fact any ''device_path'' provided will be ignored by the GRUB UEFI install script. Indeed, UEFI bootloaders do not use a MBR bootcode or partition boot sector at all.<br />
}}<br />
<br />
See [[#UEFI|UEFI troubleshooting]] in case of problems. Additionally see [[GRUB/Tips and tricks#UEFI further reading]].<br />
<br />
== Configuration ==<br />
<br />
On an installed system, GRUB loads the {{ic|/boot/grub/grub.cfg}} configuration file each boot. You can follow [[#Generated grub.cfg]] for using a tool, or [[#Custom grub.cfg]] for a manual creation.<br />
<br />
=== Generated grub.cfg ===<br />
<br />
This section only covers editing the {{ic|/etc/default/grub}} configuration file. See [[GRUB/Tips and tricks]] for more information.<br />
<br />
Remember to always [[#Generate the main configuration file]] after making changes to {{ic|/etc/default/grub}} and/or files in {{ic|/etc/grub.d/}}.<br />
<br />
==== Generate the main configuration file ====<br />
<br />
After the installation, the main configuration file {{ic|/boot/grub/grub.cfg}} needs to be generated. The generation process can be influenced by a variety of options in {{ic|/etc/default/grub}} and scripts in {{ic|/etc/grub.d/}}. <br />
<br />
If you have not done additional configuration, the automatic generation will determine the root filesystem of the system to boot for the configuration file. For that to succeed it is important that the system is either booted or chrooted into. <br />
<br />
{{Note|<br />
* Remember that {{ic|/boot/grub/grub.cfg}} has to be re-generated after any change to {{ic|/etc/default/grub}} or files in {{ic|/etc/grub.d/}}.<br />
* The default file path is {{ic|/boot/grub/grub.cfg}}, not {{ic|/boot/grub/i386-pc/grub.cfg}}.<br />
* If you are trying to run ''grub-mkconfig'' in a chroot or ''systemd-nspawn'' container, you might notice that it does not work, complaining that ''grub-probe'' cannot get the "canonical path of /dev/sdaX". In this case, try using ''arch-chroot'' as described in the [https://bbs.archlinux.org/viewtopic.php?pid&#61;1225067#p1225067 BBS post].<br />
}}<br />
<br />
Use the ''grub-mkconfig'' tool to generate {{ic|/boot/grub/grub.cfg}}:<br />
<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
<br />
By default the generation scripts automatically add menu entries for all installed Arch Linux [[kernel]]s to the generated configuration.<br />
<br />
{{Tip|<br />
* After installing or removing a [[kernel]], you just need to re-run the above ''grub-mkconfig'' command.<br />
* For tips on managing multiple GRUB entries, for example when using both {{Pkg|linux}} and {{Pkg|linux-lts}} kernels, see [[GRUB/Tips and tricks#Multiple entries]].<br />
}}<br />
<br />
To automatically add entries for other installed operating systems, see [[#Detecting other operating systems]]. <br />
<br />
You can add additional custom menu entries by editing {{ic|/etc/grub.d/40_custom}} and re-generating {{ic|/boot/grub/grub.cfg}}. Or you can create {{ic|/boot/grub/custom.cfg}} and add them there. Changes to {{ic|/boot/grub/custom.cfg}} do not require re-running ''grub-mkconfig'', since {{ic|/etc/grub.d/40_custom}} adds the necessary {{ic|source}} statement to the generated configuration file.<br />
<br />
{{Tip|{{ic|/etc/grub.d/40_custom}} can be used as a template to create {{ic|/etc/grub.d/''nn''_custom}}. Where {{ic|''nn''}} defines the precedence, indicating the order the script is executed. The order scripts are executed determine the placement in the GRUB boot menu. {{ic|''nn''}} should be greater than {{ic|06}} to ensure necessary scripts are executed first.}}<br />
<br />
See [[#Boot menu entries]] for custom menu entry examples.<br />
<br />
==== Detecting other operating systems ====<br />
<br />
To have ''grub-mkconfig'' search for other installed systems and automatically add them to the menu, [[install]] the {{Pkg|os-prober}} package and [[mount]] the partitions that contain the other systems. Then re-run ''grub-mkconfig''.<br />
<br />
===== MS Windows =====<br />
<br />
Partitions containing Windows should be automatically discovered by {{Pkg|os-prober}}. However, if the partition is encrypted, you may need to decrypt the partition before mounting. For BitLocker, this can be done with {{AUR|dislocker}}. This should be sufficient for {{Pkg|os-prober}} to add the correct entry.<br />
<br />
==== Additional arguments ====<br />
<br />
To pass custom additional arguments to the Linux image, you can set the {{ic|GRUB_CMDLINE_LINUX}} + {{ic|GRUB_CMDLINE_LINUX_DEFAULT}} variables in {{ic|/etc/default/grub}}. The two are appended to each other and passed to kernel when generating regular boot entries. For the ''recovery'' boot entry, only {{ic|GRUB_CMDLINE_LINUX}} is used in the generation.<br />
<br />
It is not necessary to use both, but can be useful. For example, you could use {{ic|1=GRUB_CMDLINE_LINUX_DEFAULT="resume=UUID=''uuid-of-swap-partition'' quiet"}} where {{ic|''uuid-of-swap-partition''}} is the [[UUID]] of your swap partition to enable resume after [[hibernation]]. This would generate a recovery boot entry without the resume and without {{ic|quiet}} suppressing kernel messages during a boot from that menu entry. Though, the other (regular) menu entries would have them as options.<br />
<br />
By default ''grub-mkconfig'' determines the [[UUID]] of the root filesystem for the configuration. To disable this, uncomment {{ic|1=GRUB_DISABLE_LINUX_UUID=true}}. <br />
<br />
For generating the GRUB recovery entry you have to ensure that {{ic|GRUB_DISABLE_RECOVERY}} is not set to {{ic|true}} in {{ic|/etc/default/grub}}.<br />
<br />
See [[Kernel parameters]] for more info.<br />
<br />
==== LVM ====<br />
<br />
{{Warning|GRUB does not support thin-provisioned logical volumes.}}<br />
<br />
If you use [[LVM]] for your {{ic|/boot}} or {{ic|/}} root partition, make sure that the {{ic|lvm}} module is preloaded:<br />
<br />
{{hc|/etc/default/grub|2=<br />
GRUB_PRELOAD_MODULES="... lvm"<br />
}}<br />
<br />
If grub-mkconfig hangs and gives error:<br />
{{ic|WARNING: Device /dev/xxx not initialized in udev database even after waiting 10000000 microseconds}}<br />
<br />
You may need to provide /run/lvm access to the chroot environment using:<br />
<br />
mkdir /mnt/hostlvm<br />
mount --bind /run/lvm /mnt/hostlvm<br />
arch-chroot /mnt<br />
ln -s /hostlvm /run/lvm<br />
<br />
==== RAID ====<br />
<br />
GRUB provides convenient handling of [[RAID]] volumes. You need to load GRUB modules {{ic|mdraid09}} or {{ic|mdraid1x}} to allow you to address the volume natively:<br />
<br />
{{hc|/etc/default/grub|2=<br />
GRUB_PRELOAD_MODULES="... mdraid09 mdraid1x"<br />
}}<br />
<br />
For example, {{ic|/dev/md0}} becomes:<br />
<br />
set root=(md/0)<br />
<br />
whereas a partitioned RAID volume (e.g. {{ic|/dev/md0p1}}) becomes:<br />
<br />
set root=(md/0,1)<br />
<br />
To install grub when using RAID1 as the {{ic|/boot}} partition (or using {{ic|/boot}} housed on a RAID1 root partition), on BIOS systems, simply run ''grub-install'' on both of the drives, such as:<br />
<br />
# grub-install --target=i386-pc --debug /dev/sda<br />
# grub-install --target=i386-pc --debug /dev/sdb<br />
<br />
Where the RAID 1 array housing {{ic|/boot}} is housed on {{ic|/dev/sda}} and {{ic|/dev/sdb}}.<br />
<br />
{{Note|GRUB supports booting from [[Btrfs]] RAID 0/1/10, but ''not'' RAID 5/6. You may use [[mdadm]] for RAID 5/6, which is supported by GRUB.}}<br />
<br />
==== Encrypted /boot ====<br />
<br />
GRUB also has special support for booting with an encrypted {{ic|/boot}}. This is done by unlocking a [[LUKS]] blockdevice in order to read its configuration and load any [[initramfs]] and [[kernel]] from it. This option tries to solve the issue of having an [[dm-crypt/Specialties#Securing the unencrypted_boot partition|unencrypted boot partition]].<br />
<br />
{{Note|{{ic|/boot}} is '''not''' required to be kept in a separate partition; it may also stay under the system's root {{ic|/}} directory tree.}}<br />
<br />
{{Warning|GRUB does not support LUKS2 headers; see [https://savannah.gnu.org/bugs/?55093 GRUB bug #55093]. Make sure you do not specify {{ic|luks2}} for the type parameter when creating the encrypted partition using {{ic|cryptsetup luksFormat}}.}}<br />
<br />
To enable this feature encrypt the partition with {{ic|/boot}} residing on it using [[LUKS]] as normal. Then add the following option to {{ic|/etc/default/grub}}:<br />
<br />
{{hc|/etc/default/grub|output=<br />
GRUB_ENABLE_CRYPTODISK=y<br />
}}<br />
<br />
This option is used by grub-install to generate the grub {{ic|core.img}}, so make sure to [[#Installation|install grub]] after modifying this option.<br />
<br />
Without further changes you will be prompted twice for a passhrase: the first for GRUB to unlock the {{ic|/boot}} mount point in early boot, the second to unlock the root filesystem itself as implemented by the initramfs. You can use a [[Dm-crypt/Device encryption#With a keyfile embedded in the initramfs|keyfile]] to avoid this.<br />
<br />
{{Warning|<br />
* If you want to [[#Generate the main configuration file|generate the main configuration file]], make sure that {{ic|/boot}} is mounted.<br />
* In order to perform system updates involving the {{ic|/boot}} mount point, ensure that the encrypted {{ic|/boot}} is unlocked and mounted before performing an update. With a separate {{ic|/boot}} partition, this may be accomplished automatically on boot by using [[crypttab]] with a [[Dm-crypt/Device encryption#With a keyfile embedded in the initramfs|keyfile]].<br />
}}<br />
<br />
{{Note|<br />
* If you use a special keymap, a default GRUB installation will not know it. This is relevant for how to enter the passphrase to unlock the LUKS blockdevice.<br />
* If you experience issues getting the prompt for a password to display (errors regarding cryptouuid, cryptodisk, or "device not found"), try reinstalling GRUB and appending {{ic|1=--modules="part_gpt part_msdos"}} to the end of your {{ic|grub-install}} command.<br />
}}<br />
<br />
{{Tip|1=You can use [https://bbs.archlinux.org/viewtopic.php?id=234607 pacman hooks]to automount your {{ic|/boot}} when upgrades need to access related files.}}<br />
<br />
=== Custom grub.cfg ===<br />
<br />
{{Expansion|Add instructions on how to write a custom {{ic|/boot/grub/grub.cfg}}. See [[User:Eschwartz/Grub]] for a proposed draft.|section=Manually generate grub.cfg}}<br />
<br />
This section describes the manual creation of GRUB boot entries in {{ic|/boot/grub/grub.cfg}} instead of relying on ''grub-mkconfig''.<br />
<br />
A basic GRUB config file uses the following options:<br />
* {{ic|(hd''X'',''Y'')}} is the partition ''Y'' on disk ''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 ''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=(hd''X'',''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 />
==== Boot menu entries ====<br />
<br />
{{Tip|These boot entries can also be used when using a {{ic|/boot/grub/grub.cfg}} generated by ''grub-mkconfig''. Add them to {{ic|/etc/grub.d/40_custom}} and [[#Generate the main configuration file|re-generate the main configuration file]] or add them to {{ic|/boot/grub/custom.cfg}}.}}<br />
<br />
For tips on managing multiple GRUB entries, for example when using both {{Pkg|linux}} and {{Pkg|linux-lts}} kernels, see [[GRUB/Tips and tricks#Multiple entries]].<br />
<br />
For [[Archiso]] and [[Archboot]] boot menu entries see [[Multiboot USB drive#Boot entries]].<br />
<br />
===== GRUB commands =====<br />
<br />
====== "Shutdown" menu entry ======<br />
<br />
{{bc|<br />
menuentry "System shutdown" {<br />
echo "System shutting down..."<br />
halt<br />
}<br />
}}<br />
<br />
====== "Restart" menu entry ======<br />
<br />
{{bc|<br />
menuentry "System restart" {<br />
echo "System rebooting..."<br />
reboot<br />
}<br />
}}<br />
<br />
====== "Firmware setup" menu entry (UEFI only) ======<br />
<br />
{{bc|1=<br />
if [ ${grub_platform} == "efi" ]; then<br />
menuentry "Firmware setup" {<br />
fwsetup<br />
}<br />
fi<br />
}}<br />
<br />
===== EFI binaries =====<br />
<br />
When launched in UEFI mode, GRUB can chainload other EFI binaries.<br />
<br />
{{Tip|1=To show these menu entries only when GRUB is launched in UEFI mode, enclose them in the following {{ic|if}} statement:<br />
<br />
{{bc|1=<br />
if [ ${grub_platform} == "efi" ]; then<br />
''place UEFI-only menu entries here''<br />
fi<br />
}}<br />
<br />
}}<br />
<br />
====== UEFI Shell ======<br />
<br />
You can launch [[Unified Extensible Firmware Interface#UEFI Shell|UEFI Shell]] by using placing it in the root of the [[EFI system partition]] and adding this menu entry:<br />
<br />
{{bc|1=<br />
menuentry "UEFI Shell" {<br />
insmod fat<br />
insmod chain<br />
search --no-floppy --set=root --file /shellx64.efi<br />
chainloader /shellx64.efi<br />
}<br />
}}<br />
<br />
====== gdisk ======<br />
<br />
Download the [[gdisk#gdisk EFI application|gdisk EFI application]] and copy {{ic|gdisk_x64.efi}} to {{ic|''esp''/EFI/tools/}}.<br />
<br />
{{bc|1=<br />
menuentry "gdisk" {<br />
insmod fat<br />
insmod chain<br />
search --no-floppy --set=root --file /EFI/tools/gdisk_x64.efi<br />
chainloader /EFI/tools/gdisk_x64.efi<br />
}<br />
}}<br />
<br />
====== Chainloading an Arch Linux .efi file ======<br />
<br />
If you have an ''.efi'' file generated from following [[Secure Boot]] or other means, you can add it to the boot menu. For example:<br />
<br />
{{bc|1=<br />
menuentry "Arch Linux .efi" {<br />
insmod fat<br />
insmod chain<br />
search --no-floppy --set=root --fs-uuid ''FILESYSTEM_UUID''<br />
chainloader /EFI/arch/vmlinuz.efi<br />
}<br />
}}<br />
<br />
===== Dual-booting =====<br />
<br />
====== GNU/Linux ======<br />
<br />
Assuming that the other distribution is on partition {{ic|sda2}}:<br />
<br />
{{bc|1=<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 />
<br />
Alternatively let GRUB search for the right partition by ''UUID'' or ''label'':<br />
<br />
{{bc|1=<br />
menuentry "Other Linux" {<br />
# assuming that UUID is 763A-9CB6<br />
search --no-floppy --set=root --fs-uuid 763A-9CB6<br />
<br />
# search by label OTHER_LINUX (make sure that partition label is unambiguous)<br />
#search --no-floppy --set=root --label OTHER_LINUX<br />
<br />
linux /boot/vmlinuz (add other options here as required, for example: root=UUID=763A-9CB6)<br />
initrd /boot/initrd.img (if the other kernel uses/needs one)<br />
}<br />
}}<br />
<br />
====== Windows installed in UEFI/GPT mode ======<br />
<br />
This mode determines where the Windows bootloader resides and chain-loads it after GRUB when the menu entry is selected. The main task here is finding the EFI system partition and running the bootloader from it.<br />
<br />
{{Note|This menuentry will work only in UEFI boot mode and only if the Windows bitness matches the UEFI bitness. It will not work in BIOS installed GRUB. See [[Dual boot with Windows#Windows UEFI vs BIOS limitations]] and [[Dual boot with Windows#Bootloader UEFI vs BIOS limitations]] for more information.}}<br />
<br />
{{bc|1=<br />
if [ "${grub_platform}" == "efi" ]; then<br />
menuentry "Microsoft Windows Vista/7/8/8.1 UEFI/GPT" {<br />
insmod part_gpt<br />
insmod fat<br />
insmod chain<br />
search --no-floppy --fs-uuid --set=root $hints_string $fs_uuid<br />
chainloader /EFI/Microsoft/Boot/bootmgfw.efi<br />
}<br />
fi<br />
}}<br />
<br />
where {{ic|$hints_string}} and {{ic|$fs_uuid}} are obtained with the following two commands. <br />
<br />
The {{ic|$fs_uuid}} command determines the UUID of the EFI system partition:<br />
<br />
{{hc|1=# grub-probe --target=fs_uuid ''esp''/EFI/Microsoft/Boot/bootmgfw.efi|2=<br />
1ce5-7f28<br />
}}<br />
<br />
Alternatively one can run {{ic|blkid}} (as root) and read the UUID of the EFI system partition from there.<br />
<br />
The {{ic|$hints_string}} command will determine the location of the EFI system partition, in this case harddrive 0:<br />
<br />
{{hc|1=# grub-probe --target=hints_string ''esp''/EFI/Microsoft/Boot/bootmgfw.efi|2=<br />
--hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1<br />
}}<br />
<br />
These two commands assume the ESP Windows uses is mounted at {{ic|''esp''}}. There might be case differences in the path to Windows's EFI file, what with being Windows, and all.<br />
<br />
====== Windows installed in BIOS/MBR mode ======<br />
<br />
{{Note|GRUB supports booting {{ic|bootmgr}} directly and [https://www.gnu.org/software/grub/manual/grub.html#Chain_002dloading chainloading] of partition boot sector is no longer required to boot Windows in a BIOS/MBR setup.}}<br />
<br />
{{Warning|It is the '''system partition''' that has {{ic|/bootmgr}}, not your "real" Windows partition (usually {{ic|C:}}). The system partition's [[Persistent block device naming#by-label|filesystem label]] is {{ic|System Reserved}} or {{ic|SYSTEM}} and the partition is only about 100 to 549 MiB in size. See [[Wikipedia:System partition and boot partition]] for more information.}}<br />
<br />
Throughout this section, it is assumed your Windows partition is {{ic|/dev/sda1}}. A different partition will change every instance of {{ic|hd0,msdos1}}.<br />
<br />
{{Note|These menu entries will work only in BIOS boot mode. It will not work in UEFI installed GRUB. See [[Dual boot with Windows#Windows UEFI vs BIOS limitations]] and [[Dual boot with Windows#Bootloader UEFI vs BIOS limitations]] .}}<br />
<br />
In both examples {{ic|''XXXXXXXXXXXXXXXX''}} is the filesystem UUID which can be found with command {{ic|lsblk --fs}}.<br />
<br />
For Windows Vista/7/8/8.1/10:<br />
<br />
{{bc|1=<br />
if [ "${grub_platform}" == "pc" ]; then<br />
menuentry "Microsoft Windows Vista/7/8/8.1/10 BIOS/MBR" {<br />
insmod part_msdos<br />
insmod ntfs<br />
insmod ntldr <br />
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 ''XXXXXXXXXXXXXXXX''<br />
ntldr /bootmgr<br />
}<br />
fi<br />
}}<br />
<br />
For Windows XP:<br />
<br />
{{bc|1=<br />
if [ "${grub_platform}" == "pc" ]; then<br />
menuentry "Microsoft Windows XP" {<br />
insmod part_msdos<br />
insmod ntfs<br />
insmod ntldr <br />
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 ''XXXXXXXXXXXXXXXX''<br />
ntldr /ntldr<br />
}<br />
fi<br />
}}<br />
<br />
{{Note|In some cases, GRUB may be installed without a clean Windows 8, in which case you cannot boot Windows without having an error with {{ic|\boot\bcd}} (error code {{ic|0xc000000f}}). You can fix it by going to Windows Recovery Console ({{ic|cmd.exe}} from install disk) and executing:<br />
<br />
X:\> bootrec.exe /fixboot<br />
X:\> bootrec.exe /RebuildBcd<br />
<br />
Do '''not''' use {{ic|bootrec.exe /Fixmbr}} because it will wipe GRUB out.<br />
Or you can use Boot Repair function in the Troubleshooting menu - it will not wipe out GRUB but will fix most errors.<br />
Also you would better keep plugged in both the target hard drive and your bootable device '''ONLY'''. Windows usually fails to repair boot information if any other devices are connected.<br />
}}<br />
<br />
== Using the command shell ==<br />
<br />
Since the MBR is too small to store all GRUB modules, only the menu and a few basic commands reside there. The majority of GRUB functionality remains in modules in {{ic|/boot/grub/}}, which are inserted as needed. In error conditions (e.g. if the partition layout changes) GRUB may fail to boot. When this happens, a command shell may appear.<br />
<br />
GRUB 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 />
<br />
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 />
<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 />
<br />
grub rescue> set prefix=(hdX,Y)/boot/grub<br />
grub rescue> insmod (hdX,Y)/boot/grub/i386-pc/normal.mod<br />
rescue:grub> normal<br />
<br />
=== Pager support ===<br />
<br />
GRUB supports pager for reading commands that provide long output (like the {{ic|help}} command). This works only in normal shell mode and not in rescue mode. To enable pager, in GRUB command shell type:<br />
<br />
sh:grub> set pager=1<br />
<br />
=== Using the command shell environment to boot operating systems ===<br />
<br />
grub><br />
<br />
The GRUB's command shell environment can be used to boot operating systems.<br />
A common scenario may be to boot Windows / Linux stored on a drive/partition via '''chainloading'''.<br />
<br />
''Chainloading'' means to load another boot-loader from the current one, ie, chain-loading.<br />
<br />
The other bootloader may be embedded at the start of a partitioned disk (MBR), at the start of a partition or a partitionless disk (VBR), or as an EFI binary in the case of UEFI.<br />
<br />
==== Chainloading a partition's VBR ====<br />
<br />
set root=(hdX,Y)<br />
chainloader +1<br />
boot<br />
<br />
X=0,1,2...<br />
Y=1,2,3...<br />
<br />
For example to chainload Windows stored in the first partition of the first hard disk,<br />
<br />
set root=(hd0,1)<br />
chainloader +1<br />
boot<br />
<br />
Similarly GRUB installed to a partition can be chainloaded.<br />
<br />
==== Chainloading a disk's MBR or a partitionless disk's VBR ====<br />
<br />
set root=hdX<br />
chainloader +1<br />
boot<br />
<br />
==== Chainloading Windows/Linux installed in UEFI mode ====<br />
<br />
insmod fat<br />
set root=(hd0,gpt4)<br />
chainloader (${root})/EFI/Microsoft/Boot/bootmgfw.efi<br />
boot<br />
<br />
{{ic|insmod fat}} is used for loading the FAT file system module for accessing the Windows bootloader on the EFI system partition.<br />
{{ic|(hd0,gpt4)}} or {{ic|/dev/sda4}} is the EFI system partition in this example.<br />
The entry in the {{ic|chainloader}} line specifies the path of the ''.efi'' file to be chain-loaded.<br />
<br />
==== Normal loading ====<br />
<br />
See the examples in [[#Using the rescue console]]<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 />
<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 />
{{Note|With a separate boot partition, omit {{ic|/boot}} from the path (i.e. type {{ic|1=set prefix=(hdX,Y)/grub}}).}}<br />
<br />
To expand console capabilities, insert the {{ic|linux}} module:<br />
<br />
grub rescue> insmod i386-pc/linux.mod<br />
<br />
or simply<br />
<br />
grub rescue> insmod linux<br />
<br />
This introduces the {{ic|linux}} and {{ic|initrd}} commands, which should be familiar.<br />
<br />
An example, booting Arch Linux:<br />
<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 (e.g. when using UEFI), again change the lines accordingly: <br />
<br />
{{Note|Since boot is a separate partition and not part of your root partition, you must address the boot partition manually, in the same way as for the prefix variable.}}<br />
<br />
set root=(hd0,5)<br />
linux (hdX,Y)/vmlinuz-linux root=/dev/sda6<br />
initrd (hdX,Y)/initramfs-linux.img<br />
boot<br />
<br />
{{Note|If you experienced {{ic|error: premature end of file /YOUR_KERNEL_NAME}} during execution of {{ic|linux}} command, you can try {{ic|linux16}} instead.}}<br />
<br />
After successfully booting the Arch Linux installation, users can correct {{ic|grub.cfg}} as needed and then reinstall GRUB.<br />
<br />
To reinstall GRUB and fix the problem completely, changing {{ic|/dev/sda}} if needed. See [[#Installation]] for details.<br />
<br />
== Troubleshooting ==<br />
<br />
=== F2FS and other unsupported file systems ===<br />
<br />
GRUB does not support [[F2FS]] file system. In case the root partition is on an unsupported file system, an alternative {{ic|/boot}} partition with a supported file system must be created. In some cases, the development version of GRUB {{aur|grub-git}} may have native support for the file system.<br />
<br />
If GRUB is used with an unsupported filesystem it is not able to extract the [[UUID]] of your drive so it uses classic non-persistent {{ic|/dev/''sdXx''}} names instead. In this case you might have to manually edit {{ic|/boot/grub/grub.cfg}} and replace {{ic|1=root=/dev/''sdXx''}} with {{ic|1=root=UUID=''XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX''}}. You can use the {{ic|blkid}} command to get the UUID of your device, see [[Persistent block device naming]].<br />
<br />
=== Intel BIOS not booting GPT ===<br />
<br />
Some Intel BIOS's require at least one bootable MBR partition to be present at boot, causing GPT-partitioned boot setups to be unbootable.<br />
<br />
This can be circumvented by using (for instance) fdisk to mark one of the GPT partitions (preferably the 1007 KiB partition you have created for GRUB already) bootable in the MBR. This can be achieved, using fdisk, by the following commands: Start fdisk against the disk you are installing, for instance {{ic|fdisk /dev/sda}}, then press {{ic|a}} and select the partition you wish to mark as bootable (probably #1) by pressing the corresponding number, finally press {{ic|w}} to write the changes to the MBR.<br />
<br />
{{Note|The bootable-marking must be done in {{ic|fdisk}} or similar, not in GParted or others, as they will not set the bootable flag in the MBR.}}<br />
<br />
With cfdisk, the steps are similar, just {{ic|cfdisk /dev/sda}}, choose bootable (at the left) in the desired hard disk, and quit saving.<br />
<br />
With recent version of parted, you can use {{ic|disk_toggle pmbr_boot}} option. Afterwards verify that Disk Flags show pmbr_boot.<br />
<br />
# parted /dev/sd''x'' disk_toggle pmbr_boot<br />
# parted /dev/sd''x'' print<br />
<br />
More information is available [http://www.rodsbooks.com/gdisk/bios.html here]<br />
<br />
=== Enable debug messages ===<br />
<br />
{{Note|This change is overwritten when [[#Generate the main configuration file]].}}<br />
<br />
Add:<br />
<br />
set pager=1<br />
set debug=all<br />
<br />
to {{ic|grub.cfg}}.<br />
<br />
=== "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 GRUB graphical terminal ({{ic|gfxterm}}) with proper video mode ({{ic|gfxmode}}) in GRUB. This video mode is passed by GRUB to the linux kernel via 'gfxpayload'. In case of UEFI systems, if the GRUB video mode is not initialized, no kernel boot messages will be shown in the terminal (atleast until KMS kicks in).<br />
<br />
{{Remove|''grub-install'' copies {{ic|unicode.pf2}} to {{ic|/boot/grub/fonts/}}, there is no need to do it manually.}}<br />
<br />
Copy {{ic|/usr/share/grub/unicode.pf2}} to {{ic|${GRUB_PREFIX_DIR}}} ({{ic|/boot/grub/}} in case of BIOS and UEFI systems). If GRUB UEFI was installed with {{ic|1=--boot-directory=''esp''/EFI}} set, then the directory is {{ic|''esp''/EFI/grub/}}:<br />
<br />
# cp /usr/share/grub/unicode.pf2 ${GRUB_PREFIX_DIR}<br />
<br />
If {{ic|/usr/share/grub/unicode.pf2}} does not exist, install {{Pkg|bdf-unifont}}, create the {{ic|unifont.pf2}} file and then copy it to {{ic|1=${GRUB_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 GRUB 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 />
After that add the following code (common to both BIOS and UEFI):<br />
<br />
{{bc|1=<br />
loadfont "unicode"<br />
set gfxmode=auto<br />
set gfxpayload=keep<br />
insmod all_video<br />
insmod gfxterm<br />
terminal_output gfxterm<br />
}}<br />
<br />
=== msdos-style error message ===<br />
<br />
grub-setup: warn: This msdos-style partition label has no post-MBR gap; embedding will not 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 GRUB in a VMware container. Read more about it [https://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 [[#Master Boot Record (MBR) specific instructions]]<br />
<br />
=== UEFI ===<br />
<br />
==== Common installation errors ====<br />
<br />
* If you have a problem when running ''grub-install'' with ''sysfs'' or ''procfs'' and it says you must run {{ic|modprobe efivars}}, try [[Unified Extensible Firmware Interface#Mount efivarfs]].<br />
* Without {{ic|--target}} or {{ic|--directory}} option, grub-install cannot determine for which firmware to install. In such cases {{ic|grub-install}} will print {{ic|source_dir does not exist. Please specify --target or --directory}}.<br />
* If after running grub-install you are told your partition does not look like an EFI partition then the partition is most likely not {{ic|Fat32}}.<br />
<br />
==== Drop to rescue shell ====<br />
<br />
If GRUB loads but drops into the rescue shell with no errors, it can be due to one of these two reasons:<br />
<br />
* It may be because of a missing or misplaced {{ic|grub.cfg}}. This will happen if GRUB UEFI was installed with {{ic|--boot-directory}} and {{ic|grub.cfg}} is missing,<br />
* It also happens if the boot partition, which is hardcoded into the {{ic|grubx64.efi}} file, has changed.<br />
<br />
==== GRUB UEFI not loaded ====<br />
<br />
An example of a working UEFI:<br />
<br />
{{hc|# efibootmgr -v|<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\grubx64.efi)<br />
Boot0001* Shell HD(1,800,32000,23532fbb-1bfa-4e46-851a-b494bfe9478c)File(\shellx64.efi)<br />
Boot0002* Festplatte BIOS(2,0,00)P0: SAMSUNG HD204UI<br />
}}<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 />
<br />
Boot0000* GRUB HD(1,800,32000,23532fbb-1bfa-4e46-851a-b494bfe9478c)File(\grubx64.efi)<br />
<br />
==== Default/fallback boot path ====<br />
<br />
Some UEFI firmwares require a bootable file at a known location before they will show UEFI NVRAM boot entries. If this is the case, {{ic|grub-install}} will claim {{ic|efibootmgr}} has added an entry to boot GRUB, however the entry will not show up in the VisualBIOS boot order selector. The solution is to install GRUB at the default/fallback boot path:<br />
<br />
# grub-install --target=x86_64-efi --efi-directory=''esp'' '''--removable'''<br />
<br />
Alternatively you can move an already installed GRUB EFI executable to the default/fallback path:<br />
<br />
# mv ''esp''/EFI/grub ''esp''/EFI/BOOT<br />
# mv ''esp''/EFI/BOOT/grubx64.efi ''esp''/EFI/BOOT/BOOTX64.EFI<br />
<br />
=== Invalid signature ===<br />
<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 />
<br />
# mv /boot/grub/device.map /boot/grub/device.map-old<br />
# grub-mkconfig -o /boot/grub/grub.cfg<br />
<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 />
=== Boot freezes ===<br />
<br />
If booting gets stuck without any error message after GRUB loading the kernel and the initial ramdisk, try removing the {{ic|add_efi_memmap}} kernel parameter.<br />
<br />
=== Arch not found from other OS ===<br />
<br />
Some have reported that other distributions may have trouble finding Arch Linux automatically with {{ic|os-prober}}. If this problem arises, it has been reported that detection can be improved with the presence of {{ic|/etc/lsb-release}}. This file and updating tool is available with the package {{Pkg|lsb-release}}.<br />
<br />
=== Warning when installing in chroot ===<br />
<br />
When installing GRUB on a LVM system in a chroot environment (e.g. during system installation), you may receive warnings like<br />
<br />
/run/lvm/lvmetad.socket: connect failed: No such file or directory<br />
<br />
or<br />
<br />
WARNING: failed to connect to lvmetad: No such file or directory. Falling back to internal scanning.<br />
<br />
This is because {{ic|/run}} is not available inside the chroot. These warnings will not prevent the system from booting, provided that everything has been done correctly, so you may continue with the installation.<br />
<br />
=== GRUB loads slowly ===<br />
<br />
GRUB can take a long time to load when disk space is low. Check if you have sufficient free disk space on your {{ic|/boot}} or {{ic|/}} partition when you are having problems.<br />
<br />
=== error: unknown filesystem ===<br />
<br />
GRUB may output {{ic|error: unknown filesystem}} and refuse to boot for a few reasons. If you are certain that all [[UUID]]s are correct and all filesystems are valid and supported, it may be because your [[#GUID Partition Table (GPT) specific instructions|BIOS Boot Partition]] is located outside the first 2 TiB of the drive [https://bbs.archlinux.org/viewtopic.php?id=195948]. Use a partitioning tool of your choice to ensure this partition is located fully within the first 2 TiB, then reinstall and reconfigure GRUB.<br />
<br />
=== grub-reboot not resetting ===<br />
<br />
GRUB seems to be unable to write to root BTRFS partitions [https://bbs.archlinux.org/viewtopic.php?id=166131]. If you use grub-reboot to boot into another entry it will therefore be unable to update its on-disk environment. Either run grub-reboot from the other entry (for example when switching between various distributions) or consider a different file system. You can reset a "sticky" entry by executing {{ic|grub-editenv create}} and setting {{ic|1=GRUB_DEFAULT=0}} in your {{ic|/etc/default/grub}} (do not forget {{ic|grub-mkconfig -o /boot/grub/grub.cfg}}).<br />
<br />
=== Old BTRFS prevents installation ===<br />
<br />
If a drive is formatted with BTRFS without creating a partition table (eg. /dev/sdx), then later has partition table written to, there are parts of the BTRFS format that persist. Most utilities and OS's do not see this, but GRUB will refuse to install, even with --force<br />
<br />
# grub-install: warning: Attempting to install GRUB to a disk with multiple partition labels. This is not supported yet..<br />
# grub-install: error: filesystem `btrfs' does not support blocklists.<br />
<br />
You can zero the drive, but the easy solution that leaves your data alone is to erase the BTRFS superblock with {{ic|wipefs -o 0x10040 /dev/sdx}}<br />
<br />
=== Windows 8/10 not found ===<br />
<br />
A setting in Windows 8/10 called "Hiberboot", "Hybrid Boot" or "Fast Boot" can prevent the Windows partition from being mounted, so {{ic|grub-mkconfig}} will not find a Windows install. Disabling Hiberboot in Windows will allow it to be added to the GRUB menu.<br />
<br />
=== VirtualBox EFI mode ===<br />
<br />
Install GRUB to the [[#Default/fallback boot path|default/fallback boot path]].<br />
<br />
See also [[VirtualBox#Installation in EFI mode]].<br />
<br />
== See also ==<br />
<br />
* [[Wikipedia:GNU GRUB]]<br />
* [https://www.gnu.org/software/grub/manual/grub.html Official GRUB Manual]<br />
* [https://help.ubuntu.com/community/Grub2 Ubuntu wiki page for GRUB]<br />
* [https://help.ubuntu.com/community/UEFIBooting GRUB wiki page describing steps to compile for UEFI systems]<br />
* [[Wikipedia:BIOS Boot partition]]<br />
* [http://web.archive.org/web/20160424042444/http://members.iinet.net/~herman546/p20/GRUB2%20Configuration%20File%20Commands.html#Editing_etcgrub.d05_debian_theme How to configure GRUB]<br />
* [http://www.linuxjournal.com/article/4622 Boot with GRUB]</div>TypicalTitan