Re: [Qemu-devel] [PATCH 00/24] Alpha system emulation, v2

[Richard Henderson <rth@twiddle.net>]

On 04/20/2011 02:06 AM, Tristan Gingold wrote:
> * sx164 is ev56 based, isn't it ?  It would be nice if cpu version specific code is clearly marked.

Yes, but most importantly it is the most evolved of the single hose systems.
QEMU is nowhere near ready to deal with multiple PCI host controllers, and
multiple ISA buses.

I actually planned on emulating an EV67 but using the SX164 HW.  I think the
Linux kernel will be that forgiving...

>   In particular (and IIRC), pal mode for ev6 is much closer to ev4 than to ev5.  Don't know about ev7.
>   It would be nice if we could easily support both ev5 and ev6.

Ah, see, here's where there may be some confusion...

I'm not implementing any of the real cpu ISRs.  I'm not using any of the real
PALcode.  I'm implementing my own QEMU-specific ISRs and and writing my own
PALcode, starting with MILO's PALcode but I've diverged significantly since.

I'm also cheating a bit and implementing a number of the simple CALL_PALs
inline in QEMU.  But that really started when I discovered how confused gdb
could get attempting to step across a transition to/from PALmode.

> * Yes, executive and supervisor are used only by VMS (well AFAIK).  I'd like to support it.

Well, if you'd like to help write the PALcode for VMS, sure.  It certainly
looks like a larger job than the Unix PALcode.

>   Did you try to also support the windows mmu mode ?

Nope.  I can't really imagine that being of interest to anyone.


r~