Re: [Qemu-devel] [PATCH] Choose emulated MIPS CPU at runtime

[Thiemo Seufer <ths@networkno.de>]

Stefan Weil wrote:
[snip]
> Perhaps some readers of the list have more information?
> >> I noticed this because some code using DI worked well with QEMU,
> >> but my AR7 based DSL router crashed...
> > Did it die with an RI exception? If not then it sounds more like
> > a missing ehb barrier. Qemu doesn't emulate pipeline hazards...
> The Linux code was ehb, then di. It crashed at the di statement.
> The kernel did not show the reason for the crash, and I have
> neither kgdb nor a hardware debugger for my router...

Do you have some linux console at the time of the crash? The Oops
dump should print out the cause register, this in turn should show
RI as the type of the last exception.

> >> AR7, it would be nice to switch between MIPS32R1 / MIPS32R2
> >> instruction sets.
> >
> > It would be nice to see a AR7 router emulation as a separate
> > machine type in Qemu. *hint* *hint* :-)
> I agree. The URL of the AR7 emulation code was published earlier on
> this list. It has grown to more than 100 KB, so I don't
> want to send it as a mail appendix to the list.
> May I send you a patch for integration? Are there any special
> requirements for this kind of patch to get acceptance?

Split it in smaller self-contained patches, and start with introducing
the new machine type before doing the drivers (so each piece can be at
least compile-tested separately).


Thiemo