crash_dump on ppc4xx ?

[vgoyal at in.ibm.com (Vivek Goyal)]

On Sat, Jan 06, 2007 at 10:14:37AM -0800, Randy Dunlap wrote:
> Hi,
> 
> Does CRASH_DUMP work on ppc4xx boards?  or are there any
> plans to do that?
> 

ppc4xx is 32bit RISC processor and AFAIK, currently crash dump
works only for ppc64. 

At least I am not aware of anybody working on it.

> I'm asking because of collisions in the sysrq key space.
> Crashdump uses sysrq-C (if CONFIG_KEXEC=y; should that
> actually be if CONFIG_CRASH_DUMP=y ?).
> 

No. The crashing kernel might not have CONFIG_CRASH_DUMP enabled. This
is common when a separate custom kernel is being built to capture the
dump. CONFIG_CRASH_DUMP needs to be enabled only if a kernel is 
used for dump capture purposes.

Hence, sysrc-C needs to remain under CONFIG_KEXEC.

> There is an IBM EMAC net driver that also uses sysrq-C,
> but it is for PPC 4xx platforms only.
> 
> So are these sufficiently mutually exclusive?  at least
> for now?
> 

I think so that these are mutually exclusive, at least for now.

Thanks
Vivek