Re: Completely disable graphics support in grub2 x86_64-efi

["KESHAV P.R." <skodabenz@gmail.com>]

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2010/8/26 Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@gmail.com>:
>>
>>  Please include the way mainline handles
>> the issue, as a fallback option in efigfx, in case no graphics/video
>> mode is found.
>>
> I don't understand what happens in your case. According to you
> "videotest" doesn't work (can you confirm?) and according to code GRUB
> in neither branch tries to detect any other way of configure graphics on
> EFI. I have a theory that for some reason Linux uses vga_text normally.
> It's possible to have this behaviour with patch at the end of this
> e-mail. But that patch can't be incorporated because there is no way to
> actualy check the availability of vga_text on EFI and on EFI as a
> firmware it's usualy not. EFI is pretty loosy firmware and is definitely
> not what I recommend. I recognize that in some cases you have to use EFI
> (if your hardware is shipped with it) but in case of DUET, it's
> specifically searching for trouble.

Grub hangs when after trying videotest in the commandline. Recent
firmwares enable bios video while older firmwares use vga_text.

I have attached the tarball of actual video driver VgaMiniPort enabled
in EDK1 DUET. The other video driver option BiosVideo is not compiling
in EDK1 DUET. I think grub2 tries for the 2nd video driver to be
present in the firmware.

> Additionaly DUET is labeled as being for test purposes only and not for
> regular use.

I know it is for test purposes only. I compile DUET (both EDK and
EDK2) in windows using visual studio. I use DUET to boot windows 7 x64
in UEFI-GPT mode because I have a GPT partitioned disk in a way hybrid
mbr cannot be used because I need access to all the partitions in
windows. Windows does not allow mixing BIOS+GPT like linux or grub2
allows. If you to try the DUET firmwares you can download it from
http://tiano-efi-duet-folder-sk.4shared.com/ where I have given
instructions on how to set it up (requires windows).

Regards.

Keshav.

> === modified file 'grub-core/loader/i386/linux.c'
> --- grub-core/loader/i386/linux.c       2010-04-21 17:13:45 +0000
> +++ grub-core/loader/i386/linux.c       2010-08-26 08:20:20 +0000
> @@ -638,7 +638,7 @@
>     }
>   else
>     {
> -#if defined (GRUB_MACHINE_PCBIOS) || defined (GRUB_MACHINE_COREBOOT) ||
> defined (GRUB_MACHINE_QEMU)
> +#if 1
>       params->have_vga = GRUB_VIDEO_LINUX_TYPE_TEXT;
>       params->video_mode = 0x3;
>  #else
>
>
>> Regards.
>>
>> Keshav
>>
>> _______________________________________________
>> Grub-devel mailing list
>> Grub-devel@gnu.org
>> http://lists.gnu.org/mailman/listinfo/grub-devel
>>
>>
>
>
> --
> Regards
> Vladimir 'φ-coder/phcoder' Serbinenko
>
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>
>

[-- Attachment #2: VgaMiniPort.tar.xz --]
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[-- Attachment #3: BiosVideo.tar.xz --]
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