[LinuxBIOS] Re: VGA support

yhlu yinghailu at gmail.com
Thu Aug 11 18:24:36 CEST 2005

That is good, but the atix.rom will be compiled into normal image and
fallback image.

Also for Fallback image, you will make linuxbios_ram.rom too big.
finally image could be greater than 128K for four way and 8 way

Maybe we can think about one way to let fallback image use the
atix.rom in normal image.

then the problem comes again: some time we need flash normal image
only and keep fallback image for safe, So You need to make sure
atix.rom in the exact same position.


On 8/11/05, Steven J. Magnani <steve at digidescorp.com> wrote:
> Yhlu writes:
> > So at last for your linuxbios.rom, you should do
> > cat atix.rom linuxbios.rom > final_linuxbios.rom
> I went through this exercise with my board last week, and this procedure
> didn't work for me. Might be because there is nothing in the LB code
> that prevents the memory range occupied by the video ROM from being
> allocated to PCI devices.
> What I finally ended up doing is creating a wrapper .S file for my
> mainboard that pulls the video ROM into the compiled LB RAM image:
>        .section .rodata.optionrom
>        .globl  _vgarom_start
> _vgarom_start:
>        .incbin
> "../../../../../src/mainboard/intel/xe7501devkit/vga.rom"
>        .globl  _vgarom_end
> _vgarom_end:
> In Config.lb I reference a symbol defined in the wrapper:
>    chip drivers/pci/onboard
>        device pci 0.0 on end
>            register "rom_address" = "_vgarom_start"
>    end
> ...and in my mainboard chip.h I forward-declare the symbol, so static.c
> can compile:
>    extern unsigned char _vgarom_start[];
> This strategy has the advantage of making the rom address independent of
> changes in the size of LinuxBIOS or the payload. The disadvantage is
> that the video ROM gets compiled into both the fallback and normal LB
> RAM images (it takes up twice as much flash space as it needs to).
> I am wondering if it might be useful for LB to support some kind of
> flash partition structure (similar to Redboot) to allow storage of
> things common to both fallback and normal images, or to support user
> selection among two or more payloads.
> ------------------------------------------------------------------------
>  Steven J. Magnani               "I claim this network for MARS!
>  www.digidescorp.com              Earthling, return my space modulator!"
>  #include <standard.disclaimer>
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