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

Gerardo Exequiel Pozzi vmlinuz386 at yahoo.com.ar
Mon Mar 26 21:34:19 EDT 2012

On 03/26/2012 11:16 AM, Keshav P R wrote:
> 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
Thanks for the work.

But this only added the advantage of passing command line options to the 
kernel. We still need a "FAT image" with bootx64.efi (rEFInd) + 
vmlinuz.efi + archiso.img (initramfs) + refind*.conf (for El Torito) 
that was the main dissapointed issue. Otherwise rEFInd can not find what 
file to load.

Gerardo Exequiel Pozzi
\cos^2\alpha + \sin^2\alpha = 1

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