[coreboot] SeaBIOS debug output

Kevin O'Connor kevin at koconnor.net
Fri Jul 25 02:24:38 CEST 2008


Hi Stefan,

On Thu, Jul 24, 2008 at 06:09:57PM +0200, Stefan Reinauer wrote:
> Any "Normal BIOS" will copy an option rom in place before executing it.  
> Most remove it afterwards.

This is surprising to me.

A typical VGA rom is going to hook int 0x10, a typical SCSI rom is
going to hook int 0x13, and a typical PXE rom is going to hook int
0x19.  None of these can then be removed.

I suppose there could be some cards that just use an option rom to
init the hardware and are then eligible for removal.  However, that
seems like it would be a very expensive way to init hardware, and so I
didn't think it would be common.

>So when dealing with compatibility to them,  
> we should aim to do things similarly

I completely agree.

Eric pointed out how an option rom can "resize" itself (and thus can
also resize itself to zero).  This does put a wrinkle in things -
having coreboot deploy the roms and seabios run them may not be
possible.

-Kevin




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