Re: m68k exception handling

[Hans-Peter Nilsson <hp at bitrange dot com>]

On Mon, 28 Nov 2005, Jim Wilson wrote:
> The DWARF2 unwind info method has little or no overhead until a
> exception is thrown.  This is the preferred method for most targets.  In
> this scheme, we read the DWARF2 unwind info from the executable when an
> exception is throw, parse the unwind tables, and then follow the
> directions encoded in the unwind tables until we reach a catch handler.
>   This approach has obvious problems if you are using a disk-less
> OS-less target board.  This approach also generally requires some C
> library support, which is present in glibc, but may not be present in
> newlib.  You can find info on this approach here
>      http://gcc.gnu.org/ml/gcc/2004-03/msg01779.html

No, everything necessary support-wise is in gcc libraries, no
special stuff from newlib is needed.  Make sure to use the right
gcc-provided start-files, though: besides the usual crt0.o
(spelling varies), crti.o and crtn.o; gcc adds crtbegin.o and
crtend.o.

(You don't really read exception tables "manually"  from the
executable at exception time; it's linked in.  You don't do that
for the normal bunch of "hosted" systems either FWIW.  It may be
different for IA64.)

brgds, H-P