Re: Possible remote.c patch for Z-packet breakpoints + Harvard + SID

[fche at redhat dot com (Frank Ch. Eigler)]

nsd wrote:

: [...]
: I see your point, though I think it's debatable.  For one thing, Z-packet
: breakpoints are tagged as "Z_PACKET_SOFTWARE_BP" in gdb/remote.c, so it
: looks like they're intended to be a generic protocol speedup rather than a
: hardware breakpoint mechanism.
: [...]

That's true - it makes me rethink my earlier point.

: I proposed a patch in January to call BREAKPOINT_FROM_PC() before rather
: than after remote.c stores hardware breakpoint addresses in outgoing
: packets, but it was decided that such a change should be at a higher
: level, e.g. in target_insert_breakpoint().
: 
: This problem can't be fixed in target_insert_breakpoint(), because the
: distinction between "hardware" (Z-packet) and software breakpoints is made
: in remote.c.
: [...]

If this gdb-side approach is not deemed acceptable to gdb folks, we
may be able to make complementary changes on the sid side without too
much littering.  

One possibility: map hardware breakpoints to mask/value-type sid
"triggerpoints" on the PC register instead of plain value-type ones;
parametrize the gdb-interface-component with the desired mask for a
target.  This sort of thing may be useful for PC-range breakpoints
too.


- FChE