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

On 03/27/2012 02:31 AM, Keshav P R wrote:

On Tue, Mar 27, 2012 at 07:04, Gerardo Exequiel Pozzi wrote:

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On 03/26/2012 11:16 AM, Keshav P R wrote:

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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

On Tue, Mar 20, 2012 at 23:15, Gerardo Exequiel Pozzi wrote: 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/c09200e2220b05bbade961bdc35f7da90d31...).

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.

No. In this case just rEFInd (and the required icons - not all of them) needs to be in the FAT image. The kernels and initramfs can be in (ISO)/efi/(SUBDIR)/ along with (ISO)/efi/(SUBDIR)/refind_linux.conf containing the kernel parameters. If the (SUBDIR) is "arch" , ie. (ISO)/efi/arch/ , then refind will even display Archlinux icon making it easy for the user to differentiate the iso kernels from other kernels.

All the answers are at http://www.rodsbooks.com/refind/ .

Regards.

Keshav

Are you sure? The only thing that can do rEFInd is launch EFI apps from drives listed by EFI firmware. A filesystem ISO9660 is not listed as a drive with filesystem by EFI, and rEFInd does not understand about ISO9660. Thanks. -- Gerardo Exequiel Pozzi \cos^2\alpha + \sin^2\alpha = 1