Bdm-osbdm is a project mainly written in C and SHELL, it's free.
BDM tools for OSBDM
The subdirectories contain:
m68k/ The ColdFire/CPU32 BDM driver and tools originally developed by W. Eric Norum and later enhanced by Chris Johns.
m683xx/ The CPU32 BDM driver enhanced by Pavel Pisa. This version offers better CPU32 support and some features not available in the m68k driver.
gdb/patches/ Patches to add BDM support to GDB.
gdb/scripts/ Example GDB command scripts that show how to initialize and run a Motorola 68360 system using standard GDB commands.
doc/ GDB BDM documentation.
schematics/ Sample schematics for building ColdFire/CPU32 BDM pods.