[Nix-dev] uefi booting on nixos

[Shea Levy]

With commit 33235 the livecd should be able to boot on most UEFI 
systems. Please let me know if it still fails on yours (make sure you 
get a cd built after that rev, of course).

On 3/18/12 8:35 AM, Shea Levy wrote:
> Hi Mathijs,
>
> On 3/18/12 8:23 AM, Mathijs Kwik wrote:
>> Little progress:
>>
>> I upgraded to kernel 3.3 and set this config:
>>
>>     boot.loader.efiBootStub = {
>>       enable = true;
>>       efiSysMountPoint = "/efi";
>>       runEfibootmgr = true;
>>       installStartupNsh = true;
>>     };
>>
>> I had to disable grub, because it was now looking for a file named
>> bzImagebzImage.
> Yeah, I had a fix for that in NixOS but my solution was awkward so I
> reverted it, I'll have to put a better one in.
>
>> I ended up with some nixos stuff on my efi partition, and a
>> startup.nsh script in the root.
>> efibootmgr shouted a few "cannot connect to efi" lines. I did modprobe
>> efivars first, but that didn't help. In bios mode, efi is just not
>> available at all.
> Yeah, efibootmgr is not expected to work in bios mode. You'll need to
> get into efi mode some other way then run
> /run/current-system/bin/switch-to-configuration boot.
>
>> So I added /startup.nsh to my boot options in the uefi shell manually.
>> Trying to boot it doesn't work though. The fallback (bios/grub) takes
>> over immediately, no error messages or anything.
> .nsh files are EFI shell scripts. \startup.nsh is a special script that
> is run automatically when the EFI shell starts if you don't press esc to
> drop straight to the shell. If your system has a uefi shell (either
> built-in, or one you have on your system partition that you launch with
> 'launch shell from filesystem', depends on your firmware), you should be
> able to just launch that and let it boot.
>
>> Are .nsh files part of the UEFI spec?
>> I was successful before booting grub2_efi. It would not let me boot
>> linux yet, but at least the menu and mode switching worked.
>>
>> Any other suggestions I can try?
> As I said above, if you can launch a UEFI shell it should automatically
> pickup startup.nsh. If not, but you have another way to add a boot
> option (e.g. through some firmware-specific menu), then you'll have to
> add \kernel.efi launched with the arguments found in startup.sh as a
> boot option. Otherwise, a fix for the CD on systems that don't support
> the protocol I used is in the pipeline.
>
>> Thanks,
>> Mathijs
>>
>>
>>
>> On Sun, Mar 18, 2012 at 12:18 PM, Mathijs Kwik<mathijs at bluescreen303.nl>   wrote:
>>> Shea Levy<shea at shealevy.com>   writes:
>>>
>>>> Hi Mathijs,
>>>>
>>>> It's not totally complete. In particular, the
>>>> installRemovableMediaImage option installs an EFI program that is a)
>>>> really hacky and b) depends on protocols not available on every
>>>> firmware (though when they're not available the boot fails with no bad
>>>> effects). I'm working with the kernel devs to ameliorate the problem
>>>> that necessitated the hack in the first place. I also need to do more
>>>> extensive testing, especially on the macbook pro. That being said, I
>>>> have been using it exclusively on my desktop for the past week or so
>>>> with several successful rebuilds, so there's that. If you do want to
>>>> try it out, I recommend trying the latest ISO from
>>>> http://hydra.nixos.org/job/nixos/trunk/iso_efi but if it doesn't boot
>>>> in EFI mode boot it in BIOS mode for the install then, if your system
>>>> supports efibootmgr, re-run switch-to-configuration after booting into
>>>> the built system to install the boot manager entries.
>>> EFI mode doesn't boot. The CD does show up as an UEFI boot option, but
>>> if I select it, I get a very fast blue flash (grub menu ?),
>>> followed by my installed (harddisk) grub starting (in bios mode).
>>>
>>> Should I just try to switch my running system to UEFI using
>>> boot.loader.efiBootStub?
>>> I guess I can always just boot my current BIOS/grub entry when it fails.
>>>
>>> I don't fully see how efibootstub would work, how does it plug in to
>>> grub2_efi? As far as I know (at least on my system) efibootmgr cannot
>>> communicate with the uefi when booted in bios mode, so I'm pretty sure I
>>> need a working boot cd, or supply the bootmgr entry in the UEFI shell
>>> myself. (I had to do that for grub2_efi on Arch)
>>>
>>> Mathijs
>>>
>>>
>>>> Let me know if you have any problems.
>>>>
>>>> Cheers,
>>>> Shea
>>>>
>>>> On 3/16/12 4:34 PM, Mathijs Kwik wrote:
>>>>> Hi Shea,
>>>>>
>>>>> I saw your commits dealing with uefi booting.
>>>>> On my laptop, windows 7 boots fine from uefi.
>>>>> However, linux doesn't. Grub-uefi boots, but something goes wrong
>>>>> (memory mapping) when handig control to the kernel.
>>>>> In the past, I've spent countless hours debugging it to no avail.
>>>>>
>>>>> I would like to give it another try someday soon.
>>>>> Do you consider your uefi changes somewhat complete? Or do you still
>>>>> have more changes planned?
>>>>>
>>>>> Anyway, thanks for your work.
>>>>>
>>>>> Mathijs
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