[Qemu-devel] Re: [Bochs-developers] BIOS, ACPI, CMOS and Windows EvenID: 4

[Sebastian Herbszt]

Gleb Natapov wrote:
> > I am not sure writing arbitrary values to those registers is such a good idea. 
> > Some OS,
> > driver or application could rely on the information stored there.
> Currently nothing is written to memory configuration registers at all,
> so if there is an application that depend on this values to be correct
> it will be broken today too.

The 440fx supports 8MB-1GB of memory. The default value for the DRBx
registers is 01 (8MB). Bochs doesn't set the default value tho nor does the
rombios set the correct one, so those registers stay with 0 values.
If we set DRB0 and DRB1 to the CMOS values and keep DRB2 till DRB7 set
to 0 we violate the assumption that DRB7 contains the top of memory value.
In the all 0 case this is still somewhat valid.

> > Hard coding the hole start to 0xe0000000, like you did in your first patch, 
> > looks like the
> > easiest solution tho.
> Yes, and I think it is good enough. What is the procedure of pushing the
> patch into bochs tree?

Post it on the bochs patch tracker at sf
http://sourceforge.net/tracker/?atid=312580&group_id=12580&func=browse

- Sebastian