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"
> >>     
> >
> > You cannot append anything to the command line this way, with the PPC
> > firmware...
> > You can append options when using yaboot, not with the -kernel option.
> > Then, you should use the CONFIG_CMDLINE kernel option to add the option
> > you absolutely need to boot.
> >   
> If you do not modify the prep loader, then it is impossible to pass 
> arguments or load a kernel that expands to > 4meg.  With respect to  
> using an unmodified prep loader, you have to build the boot arguments 
> you want into the kernel itself with the .config file options.

Any chance of pushing that loader patch back upstream?  (At least into -mm?)

> 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.

Applying said .config to 2.6.20.6 and running make oldconfig 
was...  "interesting".  Ah!  You're using ARCH=ppc to build the kernel and 
I've been using ARCH=powerpc.  I totally do not understand the difference 
between them, but I can adjust to that if it's a condition of making things 
work...  (Switch _off_ CONFIG_LOCALVERSION_AUTO "Hang the build indefinitely 
waiting for git to do who knows what"...)

Hey, I got a zImage.prep!

> > 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.
> 
> 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"

Uncompressing Linux... Segmentation fault.  But hey, it's progress.  (It got 
that far!  This is a first for me.)

This is using a 2-week old qemu cvs snapshot and not using the 2.6.21-rc you 
mentioned, and I haven't applied your patches yet, so I'll try all that next.  
But I got it to say "Uncompressing Linux..."!  This is progress!)

Thank you.

Rob
-- 
Penguicon 5.0 Apr 20-22, Linux Expo/SF Convention.  Bruce Schneier, Christine 
Peterson, Steve Jackson, Randy Milholland, Elizabeth Bear, Charlie Stross...