[linuxsh-dev] init problems on MMU-less SH-4

[Paul M. <le...@li...>]

Hi,

Running into a bit of weirdness, and was curious if anyone had seen this
before.

I'm presently running on an SH-4, with the MMU implicitly turned off
(and CONFIG_MMU unset). I've taken care of dealing with paging_init()
changes, tlb ops, etc. to deal with the lack of an MMU, and none of that
appears to be an issue. 

My current problem is that the minute init tries to start, I get endless
unaligned userspace access traps. If I implicitly flush the cache prior
to turning the MMU off, I don't have this problem, instead it runs into
a sort of livelock situation where init just hangs .. though I'm still
able to ping the target. Flushing the tlb prior to turning the MMU off
for added sanity doesn't seem to make a difference one way or the other.

Also, flushing the cache at context switch time (to work around
potential aliasing issues, SH is VIPT) doesn't seem to make a difference
here either. I haven't tried running uncached yet, though I doubt that's
an issue here.

Anyone seen this kind of behavior before? Suggestions?

Regards,

-- 
Paul Mundt <le...@li...>