Supporting extension ROMs and beyond...

Stefan Reinauer stepan at
Sat Aug 9 14:22:00 CEST 2003

* SONE Takeshi <ts1 at> [030809 19:54]:
> I don't know about freebios2 tree, but in freebios tree there is 
> some code to call POST routine of external VGA BIOS,
> and support for some realmode BIOS call (like PCI BIOS) to
> help the VGA BIOS run happily.
the code is currently only in the freebios 1.0 tree, since the freebios2
tree only includes the features that were used and tested during the PPC
and Opteron port to get rid of unneeded code. It might be a good idea to
get this code over into the freebios2 tree as an extension.

> It is activated by config like below:
>     option CONFIG_VGABIOS=1
>     option CONFIG_REALMODE_IDT=1
>     dir src/bioscall
>     option CONFIG_PCIBIOS=1
>     option VGABIOS_START=0xfffe0000
> The last line is needed when you use the VGA BIOS image from 
> the Flash (typically for onboard VGA).
What's the meaning of the other config variables? Does it make sense
to automatically use REALMODE_IDT=1, when compiling this extension
(in spe) on an x86 box, maybe in favour of CONFIG_X86EMU=1 on non-x86
platforms? The new config method might allow to make this really
readable and understandable.


More information about the coreboot mailing list