Building a newer version of gdb for ppc405 on top of Hardhat Linux 2.0
Approximate directions - please send corrections to dank@kegel.com
See also http://www.kegel.com/linux/gdbserver.html

1)  The latest release of gdb, 5.3, has multithread support in gdbserver.
    Download the source from e.g.
        ftp://sources.redhat.com/pub/gdb/releases/gdb-5.3.tar.bz2
    Unpack it:
        tar -xjvf ../gdb-5.3.tar.bz2

2)  Configure and build a local version.
    I had to pass --enable-sim-hostendian=little to fix a build error in sim/ppc
    on my little-endian build machine, and --with-solib-absolute-prefix to
    match Hardhat's directory structure.  (I also had to create the patch that
    added that option; the patch is at http://sources.redhat.com/ml/gdb/2002-07/msg00155.html
    if you want to apply it.
    I thought that was accepted, but it doesn't seem to be in gdb-5.3.)
        mkdir ppc405
        cd ppc405
        /bin/sh ../gdb-5.3/configure --target=powerpc-linux \
            --enable-sim-hostendian=little \
            --with-solib-absolute-prefix=/opt/hardhat/devkit/ppc/405/target
        make
        # Grab the gdb that created (perhaps using "make install")...
        cd ..


3)  Configure and build gdbserver for the ppc405.
        mkdir cross-ppc405
        cd cross-ppc405
        export CC=/opt/hardhat/devkit/ppc/405/bin/ppc_405-gcc
        export CFLAGS="-mcpu=403 -D__PPC405__"
        export ac_cv_func_mmap_fixed_mapped=yes
        /bin/sh ../gdb-5.3/gdb/gdbserver/configure powerpc-linux
        make 
        # Grab the gdbserver that created (perhaps using "make install")...

4)  Transfer gdbserver to the target system, telnet there, and run your program with
       gdbserver foo:1234 programname
    This tells it to listen on port 1234 for a connection from gdb.
    (The 'foo:' is required but ignored.)

5)  On your development system, run gdb with
       gdb programname

    (Optional) If you want to step into shared libraries explicitly loaded
    by your program with dlopen at runtime, tell gdb where to find them with a command like
       set solib-search-path /home/dank/ppc405/staging/fsimg/usr/lib

    Tell gdb to connect to the remote gdbserver:
       target remote 10.0.1.1:1234    

    Then set a breakpoint, e.g.
       break main
    and continue execution:
       cont