[J-core] Debug jump log?

[Rich Felker]

On Thu, Feb 23, 2017 at 01:35:53PM -0600, Rob Landley wrote:
> What would it take to add a debug feature to j-core which recorded the
> address each jump came from into a ring buffer when we set a status
> flag? I.E "start debugging mode", then run until breakpoint, then dump
> the buffer to have all the "come from" addresses so we can reconstruct
> the path that got us here back into the runtime history?
> 
> Even if it was writing the data straight into DRAM (thus slowing
> execution down a lot) it would be a really useful feature for things
> like profiling the interrupt path. (Doing that would need a register to
> set the size/location of the buffer...)

Is there a reason you'd want this in the hardware rather than an
emulator?

Rich