Re: [Qemu-devel] sparc64-softmmu Questions

[Blue Swirl]

On Wed, Oct 21, 2009 at 7:41 PM, Nick Couchman <address@hidden> wrote:
> I have a couple of questions regarding sparc64 softmmu support in Qemu:
> - Is this part of Qemu being actively developed?  Judging by the commits to 
> the git repo, it doesn't look like there's a whole lot of focus on 
> development of this right now?

It's more active architecture than many others, but of course x86 is the king.

> - Does anyone know what's left to be done for the sparc64 target to get it to 
> boot Solaris correctly?  Is there any sort of a bug repository for Qemu that 
> might list these things?  Or maybe someone has a list in their head?

There are several areas which need improvement. Sparc64 CPU emulation
seems to be mostly OK. Sun4u devices are a bit bogus and sun4v devices
do not exist yet. The Forth side of OpenBIOS is buggy, but we don't
have enough Forth experts.

> - As has already been mentioned on this list, Sun has released the Open Boot 
> PROM code (at least the sun4v version of it) under the BSD and GPL licenses.  
> What would it take to get Qemu to use the OBP code instead of OpenBIOS?  
> Looks like the OBP output isn't really an executable, and it seems like 
> sparc64-softmmu will only load Sparc ELF binaries for the BIOS.

The hypervisor code below OBP is targeting Sun's Legion simulator, not
ours or even native host.

For Solaris/Sparc64 emulation, there is more than one way:
- sparc64-softmmu/sun4u + OpenBIOS (default stack): problems described above
- sparc64-softmmu/sun4v + hypervisor + OBP: need to port the
hypervisor to QEMU, maybe fix/implement a few devices
- sparc64-solaris-user or sparc32plus-solaris-user (I sent a first cut
patch to list some time ago): the licenses are incompatible and the
user emulator would not be as useful as full system emulator.