Force FB off

Force FB off

[Jan Engelhardt]

Hi,


booting with video=off nor video=i915:off has any effect on skipping FB. 
What is the correct option to stop FB from taking over my boot consoles?


thanks,
Jan

Re: Force FB off

[Dave Airlie]

On Wed, Dec 15, 2010 at 3:41 AM, Jan Engelhardt <jengelh@medozas.de> wrote:
> Hi,
>
>
> booting with video=off nor video=i915:off has any effect on skipping FB.
> What is the correct option to stop FB from taking over my boot consoles?

For KMS its not fb taking over its the drm i915 driver, nomodeset will stop it
however X will no longer work since it relies on the kernel driver.

Dave.

Re: Force FB off

[Jan Engelhardt]

On Tuesday 2010-12-14 21:18, Dave Airlie wrote:
>On Wed, Dec 15, 2010 at 3:41 AM, Jan Engelhardt <jengelh@medozas.de> wrote:
>
>>
>>booting with video=off nor video=i915:off has any effect on skipping 
>>FB. What is the correct option to stop FB from taking over my boot 
>>consoles?
>
>For KMS its not fb taking over its the drm i915 driver, nomodeset will 
>stop it however X will no longer work since it relies on the kernel 
>driver.

That would make sense. Furthermore I discovered that video=vesafb:off 
also has no effect, but here it is clear because the source code ignores 
the return value of fb_get_options, and so ignores any off command.

The real strange thing is that video=offb:off on an Apple Xserve G5 
PPC64, while probably skipping OFFB initialization, still ends up in a 
640x480 mode with a 8x16 font instead of retaining the PROM 
console/font.

Re: Force FB off

[Rui Santos]

  Hi Jan,

     You could boot with "vga=normal i915.modeset=0". This will provide 
you with a 25x80 console.
     You can also use vga=ext for an somethingx50 console.

Regards,
Rui


On 15-12-2010 13:39, Jan Engelhardt wrote:
> On Tuesday 2010-12-14 21:18, Dave Airlie wrote:
>> On Wed, Dec 15, 2010 at 3:41 AM, Jan Engelhardt<jengelh@medozas.de>  wrote:
>>
>>> booting with video=off nor video=i915:off has any effect on skipping
>>> FB. What is the correct option to stop FB from taking over my boot
>>> consoles?
>> For KMS its not fb taking over its the drm i915 driver, nomodeset will
>> stop it however X will no longer work since it relies on the kernel
>> driver.
> That would make sense. Furthermore I discovered that video=vesafb:off
> also has no effect, but here it is clear because the source code ignores
> the return value of fb_get_options, and so ignores any off command.
>
> The real strange thing is that video=offb:off on an Apple Xserve G5
> PPC64, while probably skipping OFFB initialization, still ends up in a
> 640x480 mode with a 8x16 font instead of retaining the PROM
> console/font.
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>
>

-- 

Cumprimentos

*Rui Santos*

Email: rsantos@grupopie.com <mailto:rsantos@grupopie.com>

Re: Force FB off

[Geert Uytterhoeven]

On Wed, Dec 15, 2010 at 14:39, Jan Engelhardt <jengelh@medozas.de> wrote:
> On Tuesday 2010-12-14 21:18, Dave Airlie wrote:
>>On Wed, Dec 15, 2010 at 3:41 AM, Jan Engelhardt <jengelh@medozas.de> wrote:
>>
>>>
>>>booting with video=off nor video=i915:off has any effect on skipping
>>>FB. What is the correct option to stop FB from taking over my boot
>>>consoles?
>>
>>For KMS its not fb taking over its the drm i915 driver, nomodeset will
>>stop it however X will no longer work since it relies on the kernel
>>driver.
>
> That would make sense. Furthermore I discovered that video=vesafb:off
> also has no effect, but here it is clear because the source code ignores
> the return value of fb_get_options, and so ignores any off command.
>
> The real strange thing is that video=offb:off on an Apple Xserve G5
> PPC64, while probably skipping OFFB initialization, still ends up in a
> 640x480 mode with a 8x16 font instead of retaining the PROM
> console/font.

That just means something different than offb is driving the console now.
What does /proc/fb say?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds