RFC: Hardware watchpoint register support for mips-linux.

[Maciej W. Rozycki]

On Mon, 21 Apr 2008, David Daney wrote:

> Currently it only handles mips32 style watch registers.  I have no 
> documentation on the R4000 style registers.

 Specs for the R4000 and the R10000 (which uses the same model) are both
available online.  Search for "R4000 Microprocessor User's Manual"  
(substitute R10000 as necessary).

 The R4k-style watchpoint is trickier, as the registers hold a physical
address, so some additional handling is required for cases where the
virtual-to-physical mapping is changed (like when the area being watched
is paged in from the backing store).

  Maciej