Re: Need Help for bringing m68k-based bdm target-patches form gdb-5.2.1 to gdb-5.3

[Andreas Schwab <schwab@suse.de>]

Josef Wolf <jw@raven.inka.de> writes:

> Ough? Does that mean that gdb should not be used to debug supervisor mode?

GDB was designed to debug user level programs, which have no way to
see supervisor-only registers.  So from GDB's point of view they don't
exist.  That does not mean that GDB on m68k can not be extended to
handle them, you just need a way to get their contents from the target
(no current m68k target provides that).

>> Theses numbers are basically arbitrary, AFAIK.
>
> But there are places like 

By arbitrary I mean not externally imposed.  The numbers are chosen
for convenience inside GDB, and exposed only to the target interface,
where they are suitably translated when communicating with the target.

> BTW: I still don't have a clue what this MULTI_ARCH stuff is all about and
>      how multi-arch targets are meant to be adopted.

MULTI_ARCH means that every target architecture hooks in through the
gdbarch structure at runtime, instead of hard coding the interface
characteristics at compile time.  Targets that set GDB_MULTI_ARCH to
GDB_MULTI_ARCH_PARTIAL are not quite there yet, but the basic support
is present.

Andreas.