Steve's blog

Steve About
Steve's blog,
The Words of the Sledge

Subscribe to the RSS feed.


  • Home
  • Debian
  • PlanetDebian
  • Search PlanetDebian
  • Friends

  • Matthew Garrett
  • Jonathan McDowell
  • Jo McIntyre
  • Martin Michlmayr
  • Andrew Mobbs
  • Mike Pitt
  • Daniel Silverstone
  • Andy Simpkins
  • Neil Williams


    Monday, 30 March 2015

    UEFI Debian installer work for Jessie, part 6

    One final update on my work for UEFI improvements in Jessie!

    All of my improvements have been committed into the various Debian packages involved, and the latest release candidate for Jessie's debian-installer build (RC2) works just as well as my test builds on the Bay Trail system I've been using (Asus X205TA). Job done! :-)

    I'm still hoping to maybe get more hardware support for this particular hardware included in Jessie, but I can't promise. The mixed EFI work has also improved things for a lot of Mac users, and I'm planning to write up a more comprehensive list of supported machines in the Debian wiki (for now).

    There's now no need to use any of the older test installer images - please switch to RC2 for now. See for the images. If you want to install a 64-bit system with the 32-bit UEFI support, make sure you use the multi-arch amd64/i386 netinst or DVD. Otherwise, any of the standard i386 images should work for a 32-bit only system.


    My kernel patch to add the new /sys file was accepted upstream a while back, and has been in Linus' master branch for some time. It'll be in 4.0 unless something goes horribly wrong, and as it's such a tiny piece of code it's trivial to backport to anything remotely recent too.

    I've also just seen that my patch for grub2 to use this new /sys file has been accepted upstream this week. Again, the change is small and self-contained so should be easy to copy across into other trees too.

    Mixed EFI systems should now have better support across all distros in the near future, I hope.

    02:44 :: # :: /debian/CDs :: 11 comments


    Re: UEFI Debian installer work for Jessie, part 6
    Anonymous wrote on Mon, 30 Mar 2015 15:50

    What's the new /sys file you added? Can you talk a little more about that?

      Re: Re: UEFI Debian installer work for Jessie, part 6
      Steve wrote on Mon, 30 Mar 2015 16:09

      One of the problems with a mixed EFI system is that there is no easy way for userland programs to know whether they're running on top of a 32-bit EFI or a 64-bit EFI firmware. Clearly, most programs don't need to know! But there's a small set that do care, specifically boot loader installation programs like grub-install; it needs to know whether to generate and install grubx64.efi or grubia32.efi to make the system bootable.

      The kernel already knows whether the underlying EFI firmware is 32- or 64-bit, so we just needed an extra interface to share that information with userland. I've added a tiny patch to create a new /sys file, following the style of the existing EFI kernel interfaces:

      root@x205ta:/# cat /sys/firmware/efi/fw_platform_size

      For what it's worth, the patch is at and the corresponding patch for grub2 is at

    Re: UEFI Debian installer work for Jessie, part 6
    Simon Josefsson wrote on Mon, 30 Mar 2015 19:48

    Can you say something how well the X205TA works with rc2 in general? Have the built-in mouse/keyboard issues been solved? Does builtin wifi works? Suspend/resume? Etc.

    Thanks, Simon

      Re: Re: UEFI Debian installer work for Jessie, part 6
      Steve wrote on Tue, 31 Mar 2015 23:16

      Hi Simon,

      The keyboard and mouse work just fine, yes. In terms of other hardware, the news isn't yet so good. Playing right now, I don't have any of wifi, suspend/resume or audio working. It's going to take a while to get this machine fully supported with all features, I guess. :-/

      There's a wiki page at where I'm hoping we can co-ordinate things. I'm updating it right now.

    Re: UEFI Debian installer work for Jessie, part 6
    Carlos Peco wrote on Wed, 01 Apr 2015 07:34

    Hi Steve,

    Just saw in your blog that you were in Sydney not long ago... I would have bought you a beer or two :)

    Quick question, and sorry for my ignorance: I managed to install your image from a USB stick, but without wifi support it can not go to the servers to get a proper installation (I have no X environment, for example). What can I do to have the wifi card detected during the install ?

    thank you for your nice work !

      Re: Re: UEFI Debian installer work for Jessie, part 6
      Ravi wrote on Wed, 01 Apr 2015 15:28

      Hi Carlos: I hope it might work for you (from You will have to get the files downloaded on other computer and shift to X205TA via USB 1. get vivid rc6 kernel from 2. put other files as mentioned on DebianOn link and change config file

      Inbuilt wifi should work

        Re: Re: Re: UEFI Debian installer work for Jessie, part 6
        Carlos Peco wrote on Thu, 02 Apr 2015 03:01

        Hi Ravi,

        I'm downloading the DVD iso and will install from there. The CD iso worked, so the DVD will work as well !

        fingers crossed, thank you for the info.

    Re: UEFI Debian installer work for Jessie, part 6
    Andrea wrote on Wed, 01 Apr 2015 16:05

    Hi Steve, how can non-develepers people help? ex: kernel testing, options in kernel testing, configurations to test? thanks for your fantastic work!!!

    Re: UEFI Debian installer work for Jessie, part 6
    LordTermor wrote on Sun, 12 Apr 2015 08:38

    Hi Steve. I have a Samsung ATIV SmartPC(Intel Clover Trail) tablet. I booted into Debian installer with your improve distro, but my usb mouse and keyboard connected via usb hub isn't working so I can do nothing to start install process. Any suggestions? I want to try system itself.

    Re: UEFI Debian installer work for Jessie, part 6
    Brian wrote on Mon, 13 Apr 2015 16:46

    Tried the amd64-i386-netinst and the mac-i386-netinst CD images of RC2 on my Mac Mini (A1176/"Mid 2007"/Macmini2,1) and both of them booted the installer successfully. Didn't actually do an install, as I already have an install on it that I use on daily basis, but I will probably try later this week or next week.

    Re: UEFI Debian installer work for Jessie, part 6
    Fut wrote on Tue, 21 Apr 2015 13:00

    I tried debian-jessie-DI-rc3-i386-xfce-CD-1 on my Lenovo Miix 2 8" tablet, I booted the installer successfully with a little change in grub.cfg (set timing for boot into installer) because I have 1 usb port, so I can't connect keyboard. The installer detected hard-drive and partitions, touch screen works fine. If someone adds virtualkeyboard for installer this will be so fine :) Thank you so much!


    Your Comment

    URL/Email: [http://... or mailto:you@wherever] (optional)
    Title: (optional)
    Anti-spam:Select the third of the following words and enter it in the "Human" box
    newer notions nuncio nicety neighing nostrils ninety nippiest notation nauseous
    Save my Name and URL/Email for next time