ADLO/Bochs and PCI config write

Adam Sulmicki adam at cfar.umd.edu
Mon Jun 9 22:49:01 CEST 2003


> > > Any ideas?  It seems unlikely that the bochs stuff would be
> > that fragile so I must be missing something.
> >
> > It is :/
> >
> > turn off some deubgging stuff. it helps keep code smaller.

> Can you explain why turning off debugging macros can help?.
> I have problems when I enabled debug macros. It fail to run bochs bios.
> But If I turn off all debug macros, it boot normally.

I think there are two reasons for this.

One is that there are number of legacy entry points into bios. They are
pretty much "uniformly" scattered across the 64kb address space. Making
the available space non-contignous. (doing 'grep .org rombios.c' will show
you all those).

The second is that adding debugging information I think adds lots of more
static code to be compiled in. Both the text messages as well as the code
to the print them.

Thus i think the combined extra code with fact that the space is
noncontignous causes it to breaksomewhere. But that's just a guess It
might as well turn out to be something else. I did not investiage it too
closely.

-- 
Adam Sulmicki
http://www.eax.com 	The Supreme Headquarters of the 32 bit registers




More information about the coreboot mailing list