On 29 Sep 2020 09:46, Andrew Burgess wrote:
> * William Tambe via Gdb <gdb@sourceware.org> [2020-09-28 21:29:26 -0500]:
> > Is it possible to support gdb command hbreak with target sim ?
> 
> There's currently no support for hardware breakpoints in the simulator
> target, instead only software breakpoints are supported where GDB
> takes responsibility for reading and backing up the old memory
> contents before writing in a software breakpoint instruction.
> 
> This doesn't mean that hardware breakpoint support couldn't be added.

this is a bit inaccurate.  i guess "hardware breakpoints" are a bit
confusing when talking about simulators.  and depending on who you
talk to, they might call them "watchpoints" rather than "breakpoints".

there is a sim-watch module that some sim's support.  looks like:
  avr bfin frv iq2000 m32r mips mn10300 moxie v850

so if you're using one of those, it'd be something like:
  $ gdb <prog>
  (gdb) target sim --watch-pc-int 0x1234
  (gdb) load
  (gdb) run

that said, it appears to have a few bugs.  i'm not sure how well it's
tested :).  g'luck!
-mike