Sunday, 12 August 2012
As promised last month at DebConf, I've been working on adding EFI support to debian-cd and debian-installer, hopefully to get it up and running. At the moment, this is basic support only for booting and setting up the installed system via UEFI. I'm not worrying about "Secure" (better named "Restricted"?) Boot yet - that comes later, and depends on the basic stuff working first.
So, how is it going? Quite well, really. I've got a
branch that I'm working on locally, and with a relatively small
amount of work there I've got a locally-built CD that boots in EFI
mode, using grub-efi as a boot loader. I've borrowed a script
Next step: the installer. At the moment, generic amd64 and i386 machines are assumed to use need dos-style partitioning, and then either lilo or grub as a bootloader. I've patched and rebuilt some of the d-i packages locally to add a new sub-architecture of "efi" for both amd64 and i386, alongside the existing "generic" and "mac" variants. Using that new sub-architecture, it's possible to add checks for amd/efi and i386/efi in various places to make the necessary changes:
Why elilo? It's the default for current ia64 systems, and for EFI Macs. I tried to get grub-efi working with the grub-installer package, but with little success so far. I'll try again with grub-efi, but for now elilo is much simpler and (importantly!) it works for me.
So, I have a netinst CD built that works for me in local testing in a qemu VM using James Bottomley's OVMF build of Tianocore. It's not pretty, but it works fine, covering all the normal Debian installation steps and giving me a UEFI system at the end of the process. I'm about to start testing on real hardware now, so I think it's worth sharing this netinst image with others too. Grab it from http://cdimage.debian.org/cdimage/unofficial/efi-development/upload1/ . The "bits" subdirectory contains all the tweaked d-i packages I've played with, in both source and binary form. If you have an EFI system and would like to help us get it supported well in Debian, please download this image and play with it! Feedback to the debian-cd and/or debian-boot lists, please!