Re: booting linux-3.3 or linux 3.4 on an SGI O2?

[Thomas Bogendoerfer <tsbogend@alpha.franken.de>]

On Sat, Jun 23, 2012 at 03:30:39PM -0400, Joshua Kinard wrote:
> On 06/05/2012 3:08 PM, David Daney wrote:
> > On 06/05/2012 12:00 PM, Jim Faulkner wrote:
> >> Hi all, I haven't been able to boot any kernels after linux 3.2 on my
> >> SGI O2.  I've tried linux-3.3.5 and linux-3.4.0, but neither would boot.
> >> Unfortunately I don't have further information such as a kernel panic,
> >> since I don't get any video output after the kernel is loaded.  I've
> >> attached my linux-3.4 .config.  Anybody know what patches I might need
> >> to get the latest kernels booting on this system?
> >>
> > 
> > I have had problems as well.
> > 
> > Someone should configure a serial console and early printk to see if they
> > can see what is happening.
> 
> Early printk on O2 systems probably has the same issues as on IP22/IP28
> where it's overwriting PROM memory somewhere.  The system will hang very
> early in the bootmem allocator if you kludge early printk to work on these
> systems:

O2 is easy since it's simply a 16550 as console port chip, so no PROM
is needed and no problems like on IP22/28.

> CPU revision is: 00002733 (RM7000)

I guess the problem is here, iirc there was another RM7000 error report
due to some cache code restructering or it's RM7000 O2 problem in general.
I don't own a RM7000 cpu module for O2 ...

On my R5k O2 3.4.3 runs without problems like early 3.5 did:

mips:~# uname -a
Linux mips.franken.de 3.4.3 #2 Sun Jun 24 14:12:05 CEST 2012 mips64 GNU/Linux
mips:~# cat /proc/cpuinfo 
system type		: SGI O2
processor		: 0
cpu model		: R5000 V2.1  FPU V1.0
BogoMIPS		: 179.45

Thomas.

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