Cross debugger

GDB Cross building on FreeBSD

I recently had to build a gdb that worked on our development host, but understood arm binaries and core files. It turns out to be fairly easy to do this in the FreeBSD tree. I did this on RELENG_6, but the same techniques will work for RELENG_7 or -CURRENT.

The Cookbook

1. % setenv TARGET_ARCH arm
2. % cd /usr/src/gnu/usr.bin/binutils
3. % make depend all
4. % cd ../gdb
5. % make depend all
6. % cd gdb
   
7. # make install

These steps assume one is using csh-like shell. Commands prefixed by '%' can be run with anybody with write privs to the source tree. Commands prefixed by '#' need to be executed by root. These instructions will install a gdb-${TARGET_ARCH} in /usr/bin that can be used to look at core files, or connect to a gdbserver on the target platform. As of this writing, the arm gdbserver glue hasn't been written or committed to FreeBSD's CVS tree. The author will happily review patches and commit them if they are good enough.

Running the debugger

You can run the debugger just like you would other binaries.

1. gdb-arm binary binary.core

to get a where listing of where one went off the tracks in binary 'binary' or look at a forced core dump.

That's it! Pretty simple, all in all, to create the cross debugger.

The cross-gdb port

As has been pointed out in feedback, one can also use the devel/gdb-cross port to make this even easier. I've not used this method. Maybe I'll investigate and report in another posting.