Re: Qemu-PPC problems (was [Qemu-devel] Just to add one single point)

[Rob Landley]

On Thursday 12 April 2007 11:49 am, Jason Wessel wrote:
> J. Mayer wrote:
> > On Wed, 2007-04-11 at 17:49 -0400, Rob Landley wrote: 
> >   
> >> qemu-system-ppc -M prep -nographic -kernel zImage-powerpc -append \
> >>   "console=/dev/ttyS0"
...
> While I am sure folks have the objective to be able to boot something 
> that is not modified, my objective was to modify the kernel to work with 
> qemu until that first objective is met.  If you use a 2.6.21rc candidate 
> you can use the attached patches to boot.  I provided a .config file as 
> well.  The frame buffer is definitely broken, but I had not really 
> looked into why because I was more interested in simply using the ppc 
> instruction sets.

Ok, using a qemu CVS snapshot from this morning, I built 2.6.20.6 for powerpc 
using the config you attached to the message I'm replying to (ran make 
oldconfig on it and hit "enter", and then removed CONFIG_LOCALVERSION_AUTO, 
then built with "make ARCH=ppc CROSS_COMPILE=powerpc-" using the cross 
compiler I pointed to earlier which is configured for powerpc-unknown-linux.)

Then ran the above qemu line, and qemu segfaulted trying to decompress the 
Linux kernel.  (Is qemu supposed to segfault?  I can reproduce this quite 
easily...)

Thinking this might be the "decompresses to >4 megs" problem (your config 
produces a HUGE krenel), I then applied your patches to the kernel (the 
second is already there in .6, the first needed one hunk fixed up by hand)...

Nope, still segfaults.

> Note I startup with the following and it works perfectly fine with my 
> modified kernels:
> qemu-system-ppc -nographic -kernel zImage.prep -s -M prep -append 
> "console=ttyS0 ip=dhcp root=/dev/nfs nfsroot=10.0.2.2:/export/ppc rw 
> netdev=9,0x300,eth0"
> 
> There is a new regression between Apr 9 and Apr 10 in the QEMU CVS HEAD 
> where tcp checksums are failing again.  :-(
> 
> If it would help, I can certainly provide some of my zImage files which 
> run with several different 2.6.x kernels.

This seems to be a qemu issue.  (It really shouldn't segfault, no matter what 
the code it's emulating does.)

What qemu version are you using to run this with?

Rob
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