[LinuxBIOS] LinuxBios on Epia-ML

Richard Smith smithbone at gmail.com
Sun Dec 18 19:25:48 CET 2005

> >>found VGA: vid=1106, did=3122
> >>rom base, size: fffc0000
> >>BAD SIGNATURE 0x8 0x1e

I missed this earlier.  This indicates that the loader do_vgabios()
was unable to find the bios extension signature of 0xAA55 using the
base offset of 0xfffc0000.
Your video bios was _NOT_ copied to ram.

>>biosint: # 0x10, eax 0x4f14 ebx 0x18003 ecx 0x1 edx 0x0
>>biosint: ebp 0x17fa8 esp 0xffa edi 0x0 esi 0xffff70b6
>>biosint: ip 0x8e22 cs 0x0 flags 0x46
>>BIOSINT: Unsupport int #0x10

This is probally the result of vga_enable_console() which is called
regardless of what happens in do_vgabios() so I think its just running
bogus code.

Your rom image does not have the vga bios located correctly.  You must
locate the video bios in your ROM image such that it will get
referenced at 0xfffc0000.

For a ROM image that is 256k in size that means you need a 64k VGA
bios image located at offset 0x0.  The linuxbios image can then start
at offset 0x10000.

If you do a 'hd' on your ROM image file the very first word you see
should be 0x55aa which is the 0xaa55 rom signature in little endian.

Since the build system should have done all this for you I'm guessing
that your vga bios image is not valid.

Richard A. Smith

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