GDB / AArch64 / MacOS

[Tom Tromey]

Andrew> Maybe I could start with the AArch64/BSD target, do you think? The
Andrew> differences would be the way that args are passed between functions
Andrew> and stack layouts, I guess.

There's two parts to a gdb port like this.

One is the "tdep" code.  This holds target- and arch-dependent
information.  This is where you'd put things like knowledge of the ABI.

There's also the "nat" code.  This is host dependent code that knows how
to do low-level debugging.  E.g., linux-nat handles calling ptrace.

The split is done so cross debugging can work -- the tdep code can be
built anywhere and be used for remote debugging.  These days the nat
code tends to be shared somewhat with gdbserver, though I don't think
that was ever ported to Darwin.

For a new Darwin port you will probably need both of these.

Tom