[coreboot] noob question

[Saket Sinha]

Hi Johan,

The best way is to run coreboot on qemu, attach gdb to it and step
through all the functions to catch the flow.

Let me know if you need any help with the setup.


Regards,
Saket Sinha


On Mon, Aug 10, 2015 at 4:24 PM, Johan S <johanpsz at yahoo.fr> wrote:
> Hi there,
> i m trying to understand few mechanism in coreboot can someone help ?
> I grabbed the git tree , made crossgcc , made a biosfile tested succesfully within qemu.
> In the menuconfig few options are quite confusing especially looking at the vgabios .
> I choose the oldest qemu model for emulation , enabled the vgabios , kept the vesa framebuffer
> did the edid patch to bypasse vbe mod multiple ...
> but i can't get my splashscreen :-/
>
> johan at debian:~/coreboot$ file build/coreboot.rom ^C
> johan at debian:~/coreboot$ build/cbfstool build/coreboot.rom print
> coreboot.rom: 4096 kB, bootblocksize 928, romsize 4194304, offset 0x3c0000
> alignment: 64 bytes, architecture: x86
>
> Name                           Offset     Type         Size
> bootsplash.jpg                 0x3c0000   bootsplash   50937
> cmos_layout.bin                0x3cc740   cmos_layout  808
> fallback/dsdt.aml              0x3ccac0   raw          4000
> config                         0x3cdac0   raw          3459
> revision                       0x3ce880   raw          569
> (empty)                        0x3ceb00   null         5208
> fallback/romstage              0x3cff80   stage        11468
> fallback/ramstage              0x3d2cc0   stage        46007
> fallback/payload               0x3de0c0   payload      55823
> vgaroms/seavgabios.bin         0x3ebb40   raw          35840
> (empty)                        0x3f4780   null         46232
>
> I read somewhere that in vgabios i should be able to see :
>
> under "VGA ROM ---> VGA Hardware Type" select "coreboot linear framebuffer"
>
>
> Anyway i can get my os to boot , i can pass the F12 boot option , i can pass openfirmware but ...
> i can't even understand why with all requirement in the biosfile i could't get 1024*768
> jpeg displayed with vesa enabled ...
> I 'm lost
> Thanks
>
>
> --
> Johan S <johanpsz at yahoo.fr>
>
> --
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