remote kernel debugging with
Should a programmer be dissatisfied with the
OpenBSD kernel's internal debugger
ddb(4), and have appropriate hardware available, a kernel with
option KGDB may be built to effect remote debugging
with gdb(1) instead.
To prepare for debugging over serial line one would:
- Obtain a second system and a crossover serial cable.
- Connect the systems and test the cable.
- Build a kernel with
- Copy the resultant bsd.gdb to the control system, and boot the corresponding bsd on the target system.
- On the control system, run gdb on the kernel just copied.
- Issue the command "target remote /dev/<serial port>"
within gdb. The target system should enter
kgdbat this point.
- Debug as normal and detach when done, the target should resume normal operation.
gdb(1), ddb(4), options(4)
gdb info documents and online documentation.
The remote connection will introduce certain latencies a local debugger would not see.
Not available on all architectures.