[LinuxBIOS] MB1030 / 3036 I like 13 :D

Richard Smith smithbone at gmail.com
Wed Apr 26 21:35:24 CEST 2006

On 4/26/06, Christian Sühs <chris at suehsi.de> wrote:

> > Section 4.2.4 described the read/write access to regions between 640k -
> > 1MB There is a table on page 106. I think that is what you need.
> >
> Have a look to the src/cpu/amd/model_gx1 section
> I'm not sure, but I think the BC_XMAP_2 and BC_XMAP_3 are untouched.
> Means all is set to zero.

Yeah.  All the operations on these registers are commented out.

Heres the rub though.  Although this is a CPU thing in this case. 
This type of setting is _mainboard_ specific.  What works for you may
not be good for others.  So we can't just go setting this stuff in
here by default.  Of course there don't appeat to be too many users
and VGA is a common item so perhpas its ok.

The right way do do this seems to be to add a field into the chip
operations struct that allows the read/write of registers  either
indivdually or via a table and then the mainboard code could call that
with what it wanted to do.

But that may be a lot of extra overhead I know some of the romcc
setups are alreday tight on rom space.

To test you can just change line 36 in GX setup to be:
        .long   BC_XMAP_2, 0xb0000000

Seems to me we've had this discussion before but I never remember the result. :(

Richard A. Smith

More information about the coreboot mailing list