They seem to be fixed on Psions, although I'd like to keep this part generic,
because (1) you never know if there isn't some odd Psion model with a
different layout, and (2) we could then re-use things on the Geofox and
other 7110-based systems.
> Another question: how large VA space do you have and how large PA space the
> machine has?
The CPU has VA = PA = 4 GB, but RAM is confined to the upper 1 GB.
> If e.g. max PA range is 2GB, but VA is 4GB, then you could
> happily use 1:(1+off) mapping (or even 1:1), and map the kernel with a
> virtual mapping to some other VA (so that kernel's 2MB (or so) would have
> two mappings).
Hmm, that's a very interesting idea ! There's one issue with multiple
mappings, though: the cache works with virtual addresses, so if we
access the same page via two different addresses, our cache becomes
inconsistent. Can such a thing ever happen to kernel text, data, bss,
and friends ?
> If the above is not possible, then this should work just fine, although a
> tiny bit slower. That's what sparc32/sun4m does in most cases, so the little
> voice can stay back in your head, such scheme is tested and works.
Excellent. Things look much brighter now :)
Thanks a lot !
- Werner
-- _________________________________________________________________________ / Werner Almesberger, DI-ICA,EPFL,CH werner.almesberger@lrc.di.epfl.ch / /_IN_R_131__Tel_+41_21_693_6621__Fax_+41_21_693_6610_____________________/- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/