Re: [Qemu-devel] [6128] Use OpenBIOS for g3bw machine

["Blue Swirl" <blauwirbel@gmail.com>]

On 12/28/08, Aurelien Jarno <aurelien@aurel32.net> wrote:
> On Sun, Dec 28, 2008 at 03:08:47PM +0200, Blue Swirl wrote:
>  > On 12/28/08, Miklos Vajna <vmiklos@frugalware.org> wrote:
>  > > Hi,
>  > >
>  > >
>  > >  On Wed, Dec 24, 2008 at 08:23:52PM +0000, Blue Swirl <blauwirbel@gmail.com> wrote:
>  > >  > Revision: 6128
>  > >  >           http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6128
>  > >  > Author:   blueswir1
>  > >  > Date:     2008-12-24 20:23:51 +0000 (Wed, 24 Dec 2008)
>  > >  >
>  > >  > Log Message:
>  > >  > -----------
>  > >  > Use OpenBIOS for g3bw machine
>  > >  >
>  > >  > Modified Paths:
>  > >  > --------------
>  > >  >     trunk/hw/ppc_mac.h
>  > >  >     trunk/hw/ppc_oldworld.c
>  > >  >     trunk/qemu-doc.texi
>  > >  >
>  > >  > Modified: trunk/hw/ppc_mac.h
>  > >  > ===================================================================
>  > >  > --- trunk/hw/ppc_mac.h        2008-12-24 20:21:18 UTC (rev 6127)
>  > >  > +++ trunk/hw/ppc_mac.h        2008-12-24 20:23:51 UTC (rev 6128)
>  > >  > @@ -31,6 +31,8 @@
>  > >  >  #define BIOS_FILENAME "ppc_rom.bin"
>  > >  >  #define VGABIOS_FILENAME "video.x"
>  > >  >  #define NVRAM_SIZE        0x2000
>  > >  > +#define PROM_FILENAME    "openbios-ppc32"
>  > >  > +#define PROM_ADDR         0xfff00000
>  > >
>  > >
>  > > Is it by accident that the file 'openbios-ppc32' was not added to the
>  > >  repo?
>  >
>  > The development of OpenBIOS/PPC has been rapid, the added version
>  > would soon become obsolete. Currently OpenBIOS can boot yaboot from
>  > some install CD images but Linux hangs very early.
>  >
>
>
> By the way, I wonder if we will need a different BIOS for 32- and
>  64-bit, as a the first thing that a 64-bit kernel does is switching the
>  CPU to 64-bit mode. Also contrary to Sparc, a 32-bit code works
>  unchanged on a 64-bit CPU.

To be more precise: on Sparc64, 32-bit user code still works, the
problem is that the supervisor instructions are incompatible.
Moreover, Sun4[cdm] machine architectures are very different from
Sun4[uv].

>  If it is confirmed, we can probably rename openbios-ppc32 into
>  openbios-ppc.

Actually I tried something similar earlier today, one problem is that
g3bw machine claims it is incompatible with the bus model of PPC64.
The reset vectors are different but that can be handled with two entry
points.

As a side note, I also tried to make a cross compiler for
powerpc64-elf to try to compile OpenBIOS in 64 bit mode, but that is
not a supported configuration. Strange.