Difference between revisions of "UEFI Bootloaders"

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[[Category:Boot loaders]]
#REDIRECT [[Category:Boot loaders]]
[[zh-CN:UEFI Bootloaders]]
This page contains info about various [[UEFI]] Bootloaders capable of booting Linux kernel. It is recommended to read the [[UEFI]] and [[GPT]] pages before reading this page. The following [[Boot Loader|bootloaders]] are explained here:
== Linux Kernel EFISTUB ==
Linux (Kernel >= 3.3) supports {{ic|EFISTUB (EFI BOOT STUB)}} booting. It is enabled by by default on Arch Linux kernels or can be activated by setting {{ic|CONFIG_EFI_STUB=y}} in the Kernel configuration (see [https://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob_plain;f=Documentation/x86/efi-stub.txt;hb=HEAD The EFI Boot Stub] for more information).
A single EFISTUB kernel is not capable of launching other kernels, hence each EFISTUB Kernel + Initramfs pair requires a separate boot menu entry. It is recommended to use a UEFI Boot Manager to manage multiple kernels.
=== Setting up EFISTUB ===
#[https://wiki.archlinux.org/index.php/Unified_Extensible_Firmware_Interface#Create_an_UEFI_System_Partition_in_Linux Create a FAT32 UEFI System Partition]
# Mount the UEFI System Partition at {{ic|/boot/efi}} with {{ic|# mount <UEFI Partition> /boot/efi}} if you're going to be using GRUB2, or at {{ic|/boot}} with {{ic|# mount <UEFI Partition> /boot}} if you're going to be using Gummiboot or rEFInd. Gummiboot cannot boot across partitions, and will never have such capability due to its nature, so it's paramount that you mount the UEFI System Partition at /boot for use with Gummiboot so that the kernel and initramfs lie on the same partition as the bootmanager.
{{Note| As of [https://www.archlinux.org/packages/extra/any/refind-efi/ refind-efi 0.6.5], refind now automatically detects kernels in {{ic|/boot}}. They do not have to be renamed to have a {{ic|.efi}} extension either, as long as you are using [https://wiki.archlinux.org/index.php/UEFI_Bootloaders#Using_rEFInd refind].}}
=== Booting EFISTUB ===
{{Warning|Linux Kernel EFISTUB booting uses {{ic|\}} instead of {{ic|/}} and should be relative to the UEFI System Partition's root. For example, if the initramfs is located in {{ic|/boot/efi/EFI/arch/initramfs-linux.img}}, the corresponding UEFI formatted line would be {{ic|\EFI\arch\initramfs-linux.img}}. Failure to convert the options will lead to a system hang without any error message from the firmware or kernel.
{{Note| Support of initrd path name with {{ic|/}} in EFISTUB booting has been added in [https://patchwork.kernel.org/patch/1899361/ mainline 3.9-rc1] and [http://lwn.net/Articles/541002/ stable 3.8.2]. Leading {{ic|/}} can be ignored but the path still has to be full path. Example: {{ic|initrd&#61;EFI/arch/initramfs-linux.img}} }}
One can boot the EFISTUB kernel using one of the following ways :
==== Using rEFInd ====
rEFInd is a fork of rEFIt Boot Manager (used in Intel Macs) by Rod Smith (author of GPT-fdisk). rEFInd fixes many issues in rEFIt with respect to non-Mac UEFI booting and also has support for booting EFISTUB kernels and contains some features specific to them. More info about rEFInd support for EFISTUB is at [http://www.rodsbooks.com/refind/linux.html The rEFInd Boot Manager: Methods of Booting Linux].
# Install {{Pkg|refind-efi}} package with {{ic|# pacman -S refind-efi}}
# Copy the following files from their source directory to their destination
{{Note|1=<arch> is the bit architecture of the system. Run {{ic|$ uname -m}} to get the architecture. Replace <arch> with "ia32" for 32 bit systems, and <arch> with "x64" for 64 bit systems.}}
{| border="1"
!rEFInd File Source!!UEFI Destination
| /usr/lib/refind/refind_<arch>.efi || /boot/efi/EFI/refind/refind_<arch>.efi
| /usr/lib/refind/config/refind.conf  || /boot/efi/EFI/refind/refind.conf
| /usr/share/refind/icons || /boot/efi/EFI/refind/icons
| /usr/lib/refind/drivers_<arch> || /boot/efi/EFI/tools/drivers
{{Tip|Refind's configuration file is located in {{ic|/boot/efi/EFI/refind/refind.conf}}. The file is well commented.}}
{{Note|As of {{Pkg|refind-efi}} 0.6.5-1, refind can auto-detect kernels in {{ic|/boot}}, if there are UEFI drivers for the filesystem used by /boot partition (or / partition if no separate /boot is used) in the ESP, and are loaded by rEFInd. To enable rEFInd to detect and load the drivers and /boot kernels you must enable the appropriate options in {{ic|refind.conf}} (mainly mention the PATH for the drivers location in the ESP) and also copy your {{ic|refind_linux.conf}} to {{ic|/boot/refind_linux.conf}} .}}
{{Tip|Pass kernel specific commands by copying {{ic|/usr/lib/refind/config/refind_linux.conf}} to {{ic|/boot/efi/EFI/arch/refind_linux.conf}}. This file should be located in the same directory as the EFISTUB kernel. Edit the configuration file to be similar to the template below. Replace the string after PARTUUID with your root's PARTUUID}}
{{Note|Please notice the difference between the standard UUID and the PARTUUID shown by {{ic|$ ls -l /dev/disk/by-partuuid/}}}}
"Boot with defaults" "root=PARTUUID=3518bb68-d01e-45c9-b973-0b5d918aae96 ro rootfstype=ext4 add_efi_memmap systemd.unit=graphical.target"
"Boot to Terminal"  "root=PARTUUID=3518bb68-d01e-45c9-b973-0b5d918aae96 ro rootfstype=ext4 add_efi_memmap systemd.unit=multi-user.target"</nowiki>}}
{{Tip|Each line of {{ic|refind_linux.conf}} is displayed as a submenu by rEFInd. Access the submenu with "+" or "insert" keys.}}
{{Tip|In non-Mac systems, create an entry for rEFInd using [[UEFI#efibootmgr|efibootmgr]] where sdX is the UEFI disk, and Y is the UEFI partition number. Run :
# modprobe efivars
# efibootmgr -c -g -d /dev/sdX -p Y -w -L "rEFInd" -l '\EFI\refind\refind_<arch>.efi'
===== Systemd Automation =====
{{Tip|To automate the process of copying refind files and updating the nvram (if needed) use the following script}}
{{Note|Save this script as {{ic|/usr/lib/systemd/scripts/refind_name_patchv2}}}}
{{Tip|If you want to change the directory that refind is installed in the UEFISYS partition, just change the value of $refind_dir in the script}}
## COPYRIGHT 2013 : MARK E. LEE (BLUERIDER) : mlee24@binghamton.edu; mark@markelee.com
## LOG
## 1/17/2013 : Version 2 of refind_name_patch is released
##          : Supports long subdirectory location for refind
##          : Updates nvram when needed
##          : 10% speed boost
function main () {  ## main insertion function
  declare -r refind_dir="/boot/efi/EFI/refind"; ## set the refind directory
  declare -r arch=$(uname -m | awk -F'_' '{if ($1 == "x86"){print $2}}') &&  ## get bit architecture
  update-efi-dir;  ## updates or creates the refind directory
  update-efi-nvram;  ## updates nvram if needed
function update-efi-dir () {  ## setup the refind directory
  if [ ! -d $refind_dir ]; then  ## check if refind directory exists
    echo "Couldn't find $refind_dir";
    mkdir $refind_dir &&  ## make the refind directory if needed
    echo "Made $refind_dir";
  if [ "$arch" ]; then  ## check if anything was stored in $arch
    cp -r /usr/{share/refind/*,lib/refind/refind_x*$arch*.efi} $refind_dir/ && ## update bin and dirs
    echo "Updated binaries and directory files for refind at $refind_dir";
    echo "Failed to detect an x86 architecture";
function update-efi-nvram () { ## update the nvram with efibootmgr
  declare -r ref_bin=${refind_dir/\/boot\/efi}/$(ls /usr/lib | grep $arch*.efi);  ## get path of refind binary (without /boot/efi)
  declare -r ref_bin_escape=${ref_bin//\//\\\\};  ## insert escape characters into $ref_bin
  modprobe efivars && ## grab the efi variables for efibootmgr
  efibootmgr -v | grep $ref_bin_escape && ( ## check if boot entry is in nvram
    echo "Found boot entry, no need to update nvram";
    ) || ( ## if boot entry is not in nvram; add it
    declare -r esp=$(mount -l | awk '/ESP/ {print $1}') &&  ## get ESP partition
    efibootmgr -c -g -d ${esp:0:8} -p ${esp:8} -w -L "rEFInd" -l $ref_bin_escape && ## update nvram
    echo "
    Updated nvram with entry rEFInd to boot $ref_bin
    Did not copy configuration files, please move refind.conf to $refind_dir/";
main;  ## run the main insertion function
{{Note|Save the following service file as {{ic|/usr/lib/systemd/system/refind_update.path}}}}
Description=Update rEFInd bootloader files
{{Note|Save the following service file as {{ic|/usr/lib/systemd/system/refind_update.service}}}}
Description=Update rEFInd directories, binaries, and nvram
ExecStart=/bin/bash /usr/lib/systemd/scripts/refind_name_patchv2
{{Tip|Enable the systemd path unit by running :
# systemctl enable refind_update.path
===== Apple Macs =====
In case of Apple Macs, try {{AUR|mactel-boot}} for an experimental "bless" utility for Linux. If that does not work, use "bless" form within OSX to set rEFInd as default bootloader. Assuming UEFISYS partition is mounted at {{ic|/mnt/efi}} within OSX, do
$ sudo bless --setBoot --folder /mnt/efi/EFI/refind --file /mnt/efi/EFI/refind/refind_x64.efi
===== VirtualBox =====
In case of VirtualBox, see [[VirtualBox#Using_Arch_under_Virtualbox_EFI_mode]].
==== Using gummiboot ====
[[Gummiboot]] is a UEFI Boot Manager which provides a nice menu for EFISTUB Kernels. It is available in [extra] as {{Pkg|gummiboot}}. See https://wiki.archlinux.org/index.php/Gummiboot for more info.
==== Using UEFI Shell ====
It is possible to launch EFISTUB kernel form UEFI Shell as if it is a normal UEFI application. In this case the kernel parameters are passed as normal parameters to the launched EFISTUB kernel file.
> fs0:
> cd \EFI\arch
> vmlinuz-arch.efi root=PARTUUID=3518bb68-d01e-45c9-b973-0b5d918aae96 ro rootfstype=ext4 add_efi_memmap initrd=EFI/arch/initramfs-arch.img
You can also write a simple {{ic|archlinux.nsh}} file with your boot parameters and put it in your UEFI System Partition, then run it with:
Example Script:
echo -on
\EFI\arch\vmlinuz-arch.efi root=PARTUUID=3518bb68-d01e-45c9-b973-0b5d918aae96 ro rootfstype=ext4 add_efi_memmap initrd=EFI/arch/initramfs-arch.img
This way you can specify UUID's without needing to remember the name or type out 20-30 characters.
==== Using efibootmgr entry ====
{{Note|1=This method may not work due to [https://git.kernel.org/?p=linux/kernel/git/mfleming/efi.git;a=commitdiff;h=b003aaf799c991295b8b73e8f940d20bda2c1bbb;hp=ddffeb8c4d0331609ef2581d84de4d763607bd37 limitations in how the kernel handles uefi runtime variables]. For example in some Lenovo Thinkpads the initrd path is truncated (verified using {{ic|efibootmgr -v}} command) and therefore the kernel fails to boot.}}
{{Note|Some UEFI firmwares may not support embedding command line parameters to uefi applications in the boot entries.}}
It is possible to directly embed the kernel parameters within the boot entry created by efibootmgr. This means that in your BIOS/UEFI you will be able to select Arch Linux directly in the default boot order, and on startup it will boot into Arch directly without any kind of boot selection GUI.
Do (as root):
Install efibootmgr if you haven't already.
  # pacman -S --needed efibootmgr
Load the EFI module.
# modprobe efivars
Finally, add the efistub.
WARNING: Make sure you replace the following before running this command:
* ''/dev/sda'' -- the drive that contains the EFI boot partition
* ''-p 1'' -- the partition number of the EFI boot partition
* ''/dev/sda2'' -- your {{ic|/}} partition
* ''ext4'' -- if you use a different file system
# efibootmgr -c -d /dev/sda -p 1 -L "Arch Linux" -l '\EFI\arch\vmlinuz-arch.efi' -u root=UUID=$(blkid /dev/sda2 -o value -s UUID) ro rootfstype=ext4 add_efi_memmap initrd=EFI/arch/initramfs-arch.img
It is a good idea to run
# efibootmgr -v
to verify that the resulting entry is correct. You should also consider reordering the boot options ({{ic|efibootmgr -o}}) to place the Arch entry last, which could make the system easier to recover if it fails.
More info about efibootmgr at [[UEFI#efibootmgr]]. Forum post https://bbs.archlinux.org/viewtopic.php?pid=1090040#p1090040 .
{{Note|Some firmwares may have trouble with the "initrd path" when using ucs-2 as shown above. In this case, one may put vmlinuz-linux.efi and the initramfs in the root of the ESP and adjust the efibootmgr entry accordingly.}}
When booting using this method, care must be taken to synchronize the kernel with the ESP following a kernel upgrade but before rebooting. If you fail to do so, your system will not boot until you update the ESP by some other means (e.g. using the installation media to mount your hard drive).
== GRUB 2.x ==
GRUB 2.x contains its own filesystem drivers and does not rely on the firmware to access the files. It can directly read files from {{ic|/boot}} and does not require the kernel and initramfs files to be in the UEFISYS partition. Detailed information at [[GRUB#UEFI_systems_2]]. For bzr development version try AUR package - {{AUR|grub-efi-x86_64-bzr}}.
{{Note|Syslinux UEFI support is currently part of version 6.00-preXX or in firmware branch of upstream git repo. It is considered alpha quality by upstream. The below information is provided mainly to enable bug-testing. Please report all issues upstream.}}
{{Note|Syslinux UEFI can boot only those kernels that support '''EFI Handover Protocol'''. Thus LTS kernels are not supported.}}
Install {{AUR|syslinux-efi-git}} AUR package and copy {{ic|/usr/lib/syslinux/efi64/*}} to {{ic|$esp/EFI/syslinux/}} ({{ic|$esp}} is the mountpoint of UEFISYS partition) ({{ic|efi64}} is for x86_64 UEFI firmwares, replace with {{ic|efi32}} for i386 UEFI firmwares), and then create a boot entry using efibootmgr in the firmware boot manager.
== ELILO ==
ELILO is the UEFI version of LILO Boot Loader. It was originally created for Intel Itanium systems which supported only EFI (precursor to UEFI). It is the oldest UEFI bootloader for Linux. It is still in development but happens at a very slow pace. Upstream provided compiled binaries are available at http://sourceforge.net/projects/elilo/ . Elilo config file {{ic|elilo.conf}} is similar to [[LILO]]'s config file. AUR package - {{AUR|elilo-efi-x86_64}} (only for x86_64 UEFI).
EFILINUX is a reference implementation of a UEFI Linux bootloader and precursor to Kenrel EFISTUB support. It is considered to be a alpha quality software (as on 16-MAY-2012). Upstream sources are at https://github.com/mfleming/efilinux . and the usage instructions are at http://thread.gmane.org/gmane.linux.kernel/1172645 and http://article.gmane.org/gmane.linux.kernel/1175060 . AUR packages - {{Pkg|efilinux-efi}} and {{AUR|efilinux-efi-x86_64-git}} (only for x86_64 UEFI).
== Package Naming Guidelines ==
UEFI bootloader package(s) should be suffixed with {{ic|-efi-x86_64}} or {{ic|-efi-i386}} to denote package built for 64-bit and 32-bit UEFI respectively. If a single package contains both 64-bit and 32-bit UEFI applications, then {{ic|-efi}} suffix should be used in the '''pkgname'''.
== See also ==
* [http://www.rodsbooks.com/efi-bootloaders/ Rod Smith - Managing EFI Boot Loaders for Linux]
* [http://www.rodsbooks.com/refind/ Rod Smith - rEFInd, a fork or rEFIt]
* [https://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob_plain;f=Documentation/x86/efi-stub.txt;hb=HEAD Linux Kernel Documentation on EFISTUB]
* [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=291f36325f9f252bd76ef5f603995f37e453fc60;hp=55839d515495e766605d7aaabd9c2758370a8d27 Linux Kernel EFISTUB Git Commit]
* [http://www.rodsbooks.com/efi-bootloaders/efistub.html Rod Smith's page on EFISTUB]
* [http://www.rodsbooks.com/refind/linux.html rEFInd Documentation for booting EFISTUB Kernels]

Latest revision as of 02:37, 10 July 2016