Re: Qemu

Hi Peter,

I think qemu on OpenBSD/macppc will not help you as this will be still 
using tcg IMHO. What you would need is something like Linux on PPC64 and 
running KVM there and then IMHO you will be able to run PPC code 
directly on CPU avoiding possible Qemu issues in PPC isns backend.

See following URLs about how to run Mac OS X for PPC on top of Qemu/KVM 
on POWER9/Linux box:
https://www.talospace.com/2018/08/making-your-talos-ii-into-power-mac.html

https://www.talospace.com/2018/08/making-your-talos-ii-into-power-mac_29.html

I have POWER8 + Linux + KVM box here which is kind of working well since 
in Qemu/KVM I'm running various Linuxes and FreeBSD 13-current. If you 
like to have something tested there, I'm open to it, either will do it 
myself or I'll give you account on the box.
Yet another possibility would be to ask RaptorCS since they promised 
several times bare-metal access to POWER9 box to OS porters.

Could you be also so kind and share information about how do you build 
OpenBSD for PPC64 and how do you boot whatever you get from the build. 
I'm especially curious if you build bsd.rd and somehow boot that and how 
exactly do you invoke Qemu and also what Qemu version exactly do you use 
for that.

Thanks,
Karel

On 5/25/19 2:07 AM, Peter J. Philipp wrote:
> Hi,
> 
> Last week I worked a bit on my powerpc64 port and I ran into some trouble.
> I'll try to formulate what that trouble was in another post (maybe) in the
> next few days but I just have this question:  How can I use Qemu better?
> I'm using the 970FX emulation with 1 cpu for now and I'm running into some
> LR register corruption, and at first glance it seems the asm is alright (in
> that it saves LR on the stack after a mflr, and pops the stack later and
> restores LR with mtlr.
> 
> Would it be beneficial to use Qemu on the macppc arch instead of the amd64
> arch or doesn't it matter?  One good thing with the amd64 arch is that I can
> take my work along on weekends to my parents house, where i have no access to
> the G5.  I'm not letting the G5 idle at 140 Watts.
> 
> The 6.5 macppc qemu is broken, so I'll have to take my G5 to -current perhaps
> to see if I can get qemu to compile.
> 
> Another thing with Qemu that I have problems with is the entire 'show registers' output in the monitor, it doesn't feel like it correctly displays right data.
> I have also used the x (examine) function in the monitor which is like the gdb
> memory examination.  Is there any other monitor commands that you might have
> experience with that are a really good debug tool?
> 
> Regards,
> -peter
>