Re: [Qemu-ppc] Regression in ppc-softmmu when running HelenOS

[Jakub Jermar]

Hi Mark,

On 03/12/2012 05:26 PM, Mark Cave-Ayland wrote:
> I haven't managed to get as far as I liked on this to date (mainly as
> there was another bug preventing VGA in git master from PPC working),
> but I did manage to at least get HelenOS to boot with the (incomplete)
> attached patch against git master. I don't believe this is necessarily
> the full solution since I find the booted image is quite console
> lethargic (and can lose/return incorrect keypresses).
> 
> The reason I hadn't updated the bug was because I still wasn't sure if
> this was part of the QEMU performance regression I noticed when
> comparing old/new versions of HelenOS or simply because the flag
> handling for calculating new_msr is still incomplete. Some searching
> revealed the  link http://www.systemcomputing.org/ppc/ppc4.htm which
> seems to indicate that the MSR modification upon entry to the interrupt
> routine could be different to the list of always-zeroed flags removed by
> the mask (which is what pointed me in this direction in the first place).
> 
> Anyway, I include the patch as discussion point - don't forget that you
> need to boot QEMU with the openbios-ppc image from 0.11 stable branch if
> you currently wish to test this.

(Cc: to helenos-devel@)

I tried your patch with the latest HelenOS mainline. The user experience
seems the same compared to what you get with Qemu 0.11.1, meaning that
in both cases the clock seems to go too fast (could be a HelenOS bug),
but otherwise the system boots and runs fine.

Jakub