[arch-releng] [DRAFT][RFC][PATCH][archiso] Add UEFI boot support via Linux >= 3.3 EFI boot stub.

[Keshav P R]

On Tue, Mar 20, 2012 at 23:15, Gerardo Exequiel Pozzi
<vmlinuz386 at yahoo.com.ar> wrote:
>
>>
>> This is going to increase the iso size like hell. Having the kernel
>> and initrd files within a FAT image inside the iso is not a good idea.
>> A 32 MB fat image, come on. I know this is required for CD booting,
>> but this is not a good idea with efistub efilinux or elilo etc. For
>> USB booting you can just have the files in the iso itself, wherein the
>> user simply extract the iso in a FAT32 USB and boots from it. I say
>> drop support for iso booting via this fat fs image and support uefi
>> boot only in case of USBs.
>>
>> Regards.
>>
>> Keshav
>>
>
> OK, so just ignore this draft patch. UEFI boot support can be made manually by the user, just doing a copy of vmlinuz to the right place and optionally installing a boot manager.
>
> A documentation on the wiki is sufficient.

You might be interested in rEFInd-x86_64
https://aur.archlinux.org/packages.php?ID=57632 which provides a nice
menu for EFISTUB kernels.

Related info :
http://www.rodsbooks.com/refind/linux.html
http://www.rodsbooks.com/efi-bootloaders/efistub.html

[QUOTE from http://www.rodsbooks.com/refind/linux.html]
rEFInd looks for a file called linux.conf in the same directory as the
kernel file. This file is a practical requirement for booting from an
auto-detected kernel. It consists of a series of lines, each of which
consists of a label followed by a series of kernel options. The first
line sets default options, and subsequent lines set options that are
accessible from the main menu tag's submenu screen.

The intent of this system is that distribution maintainers can place
their kernels, initial RAM disks, and a linux.conf file in their own
subdirectory on the ESP. rEFInd will detect their kernels and create
one main menu entry for each kernel. Each entry will implement as many
options as there are lines in the linux.conf file. In this way, two or
more distributions can each maintain their boot loader entries,
without being too concerned for who maintains rEFInd as a whole.
[/QUOTE]

The filename has been changed to refind_linux.conf in the upstream git
repo so that it does not conflict with the proposed efistub config
file by kernel devs
(http://sourceforge.net/p/refind/code/ci/c09200e2220b05bbade961bdc35f7da90d318abf/).

This should be pretty straightforward to implement in Archiso. For
non-EFISTUB kernels like LTS ones, you can use efilinux-x86_64
https://aur.archlinux.org/packages.php?ID=57972 (Usage instructions -
http://thread.gmane.org/gmane.linux.kernel/1172645 and
http://article.gmane.org/gmane.linux.kernel/1175060). This might be a
good alternative for grub2 uefi boot, although booting i686 kernels in
x86_64 UEFI will not be supported by EFISTUB (which can be done using
grub2). Support for mixed arch booting seems to have been merged for
3.4-rc1 .

Regards.

Keshav