Re: breakpoint extension for remote protocol

[Jim Blandy <jimb@cygnus.com>]

For the record, Zdenek Radouch pointed out a while back on the
internal GDB mailing list a distinction that I liked:

There are actually three "architectures" that we care about:
  - the architecture of the processor itself
  - the ABI and calling conventions (controlled by the compiler/linker
    environment)
  - the target board architecture (excluding the CPU)

At present, we kind of smoosh them all together, which causes
confusion when someone else needs to wade into our code and
disentangle our assumptions.  We support multiple ABI's for the MIPS
and PPC (at least), and (I think???) you have to select the one you
want at configuration time (--target=powerpc-eabi, for example).  So
we are already drifting away from "generic" embedded toolchains, which
I agree is bad.

When we estimate new GDB ports, we should include time to actually
segregate those three things nicely, so that GDB could have a "set
abi" and "set board" command.  Otherwise, if GDB is really to know all
that stuff (as Stan has said it should), it's going to be a total mess.