Commit 6912bdb7 authored by Nir Lichtman's avatar Nir Lichtman Committed by Jonathan Corbet
Browse files

Documentation: Fix x86_64 UEFI outdated references to elilo 



Problem: The x86_64 UEFI doc references Elilo which is an
unmaintained/orphaned bootloader project. Also, on x86_64 a bootloader
is technically not actually required since there is support for the
Linux EFI stub.

Solution: Remove the references to Elilo from the doc and refer to the
EFI stub doc page, update steps accordingly, and add more details about
creation of the EFI partition to improve clarity.

Signed-off-by: default avatarNir Lichtman <nir@lichtman.org>
Link: https://lore.kernel.org/r/20250108113522.GA897677@lichtman.org


Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent e129fdc5

Documentation/arch/x86/x86_64/uefi.rst

+27 −10
Original line number Diff line number Diff line
@@ -12,14 +12,20 @@ with EFI firmware and specifications are listed below. 


1. UEFI specification:  http://www.uefi.org



2. Booting Linux kernel on UEFI x86_64 platform requires bootloader

   support. Elilo with x86_64 support can be used.

2. Booting Linux kernel on UEFI x86_64 platform can either be

   done using the <Documentation/admin-guide/efi-stub.rst> or using a

   separate bootloader.



3. x86_64 platform with EFI/UEFI firmware.



Mechanics

---------



Refer to <Documentation/admin-guide/efi-stub.rst> to learn how to use the EFI stub.



Below are general EFI setup guidelines on the x86_64 platform,

regardless of whether you use the EFI stub or a separate bootloader.



- Build the kernel with the following configuration::



	CONFIG_FB_EFI=y
@@ -31,16 +37,27 @@ Mechanics 
	CONFIG_EFI=y

	CONFIG_EFIVAR_FS=y or m		# optional



- Create a VFAT partition on the disk

- Copy the following to the VFAT partition:

- Create a VFAT partition on the disk with the EFI System flag

    You can do this with fdisk with the following commands:



        1. g - initialize a GPT partition table

        2. n - create a new partition

        3. t - change the partition type to "EFI System" (number 1)

        4. w - write and save the changes



    Afterwards, initialize the VFAT filesystem by running mkfs::



        mkfs.fat /dev/<your-partition>



- Copy the boot files to the VFAT partition:

    If you use the EFI stub method, the kernel acts also as an EFI executable.



    You can just copy the bzImage to the EFI/boot/bootx64.efi path on the partition

    so that it will automatically get booted, see the <Documentation/admin-guide/efi-stub.rst> page

    for additional instructions regarding passage of kernel parameters and initramfs.



	elilo bootloader with x86_64 support, elilo configuration file,

	kernel image built in first step and corresponding

	initrd. Instructions on building elilo and its dependencies

	can be found in the elilo sourceforge project.

    If you use a custom bootloader, refer to the relevant documentation for help on this part.



- Boot to EFI shell and invoke elilo choosing the kernel image built

  in first step.

- If some or all EFI runtime services don't work, you can try following

  kernel command line parameters to turn off some or all EFI runtime

  services.