Evening 9fans,

While working on the Chromebook (nee exynos) port I ended up in a
situation where I needed to use a more sophisticated JTAG debugger to
find an issue. I ended up grabbing a RealView ICE since they are
relatively cheap on eBay (around 500.00USD) compared to other models
capable of debugging Cortex-A15 cores. Older firmware revisions of the
 RVI support the remote GDB protocol (in addition to the closed RDDI
protocol). I've written a simple 9P file server that translates
memory/register accesses to remote GDB targets. I haven't tried it
yet, but this should also work with OpenOCD as well.

At the moment this is little more than a toy, but it has been stable
enough for me to debug issues on the board reliably. I've added
support for ARM and i386 for now - adding additional register maps for
the other mach types is straightforward. If there is enough demand,
I'll write up a man page and submit a patch. The setup for this isn't
particularly obvious since it requires some messing about with RVI
firmware updates and downloading the right version of RVDS to setup
the board, so a wiki page is deserved as well.

For now, you can find the source in my contrib directory on sources:
/n/sources/contrib/stallion/src/gdbfs/

(Obligatory screenshot attached)

Cheers,

Steve