> where can I find more info on what Data Storage interrupt is and what may
> cause it

Canonically, from "The PowerPC Architecture: Insert Overdramatic
Subtitle That I Forget Here", which is the absolute reference for the
chip. You may or may not be able to find it at any given bookstore
with lots of computer books. (Lots of places don't seem to stock
non-PC hardware books though. Grumble.) You can also find other
PowerPC programming references which would probably tell you too.

Anyway, a DSI is a failed attempt to reference memory, which usually
means either a page fault (which the kernel should handle) or a bad
pointer dereference (which the kernel should convert into a SIGSEGV if
it came from userland).

-- Dan

PS - Oh, found it, it's "The PowerPC Architecture: A Specification for
a New Family of RISC Processors" (Second Edition, Morgan Kauffman
Publishers, ISBN 1-55860-316-6). I guess it's not that overdramatic...