I'm currently playing with an old Sonicwall NSA3500. It's pretty locked but you have native access to the console and you can set via jumper the boot source, flash, dbgrom and eeprom. The eeprom is a SST 39VF040 PLCC32 which I take out and programm it with my RT809H.
The main problem is that I'm not able to find a bootloader for the Octeon CN58XX. I have one for CN5020 but that's not working...
It would be also interesting if someone has a configuration file for openocd. Autotap is not working.
Can you help me?