Re: [Qemu-devel] [PATCH] Re: phys_ram_base, direct access to guest memory

[Fabrice Bellard]

Blue Swirl wrote:
> On 5/5/08, Aurelien Jarno <address@hidden> wrote:
> > On Fri, May 02, 2008 at 05:52:07PM +0300, Blue Swirl wrote:
> >  > On 4/8/08, Aurelien Jarno <address@hidden> wrote:
> >  > > On Tue, Mar 25, 2008 at 11:12:57AM +0000, Ian Jackson wrote:
> >  > >  > I wrote:
> >  > >  > > In the attached patch, I remove all the direct uses of phys_ram_base
> >  > >  > > from hw/pc.c, except for those presently needed to construct the
> >  > >  > > arguments to the vga init functions.
> >  > >  >
> >  > >  > Is there something wrong with my patch or the general approach ?
> >  > >
> >  > >
> >  > > It simply doesn't work. After applying it, I get:
> >  > >
> >  > >
> >  > >  qemu: fatal: Trying to execute code outside RAM or ROM at 0x000a0000
> >  >
> >  > I fixed the bug in the patch, cpu_physical_memory_write_rom must be
> >  > used instead of cpu_physical_memory_write. I also made the same
> >  > changes to Sparc32/64, they run fine. Does this version work for PC
> >  > targets?
> >
> >
> > Unfortunately the problem is still there, with the same error message.
>
> There were two additional problems, the offset was incorrect and the
> memory was written before it was mapped. This version seems to work.
>
> Any objections? May I commit this version?

OK for the kernel loading, but not for the BIOS loading : there is no 
reason all the BIOS is mapped at a particular physical address (because 
this address is selectable by specific chipset bits), so it must really 
be loaded at ram addresses, not at physical addresses.

IMHO, it still makes sense to allow loading of data at a particular ram 
address.

Regards,

Fabrice.