x86 programming question
cjohns at cybertec.com.au
Fri Aug 24 19:23:28 UTC 2001
Joel Sherrill wrote:
> I know the interrupt and know how to write the code in real mode to do
> this call. However,
> the results of this call are of more use in protected mode. So I saw
> only a handful of options:
> + figure out how to do the BIOS call in protected mode
> + do the BIOS call in real mode and figure out how to save the results
> in memory in such a way that they can be retrieved in protected mode.
> + (from Rosimildo) leave the memory size in a register at the time of
> transition from real to protected mode then save it away for later use.
> So ideally I would like a generic way to perform a BIOS call from protected
I suggest you look into the Etherboot project code on SourceForge :
Look in start32.S in the src directory. Near the end is call to switch
between protected and real mode. Maybe they will help.
Chris Johns, cjohns @ cybertec.com.au
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