[OpenOCD-devel] Fork for basic support of xPC56/PowerPC E200

[Antoine C. <aca...@fr...>]

Hi all,

After an announcement a few month ago (https://sourceforge.net/p/openocd/mailman/message/36182151/), I am glad to present a basic working implementation for xPC56 chips support:
https://github.com/calandoa/openocd

Currently, the following operations can be done on a SPC560D-DIS board with a FT232H:
- read/write RAM via Nexus2 or scan chain
- read/write flash
- halt/step/resume
- dump some registers
- add/remove HW breakpoints

This is only working via telnet, I did not tried gdb yet. The code is also full of bugs and only working in very simple cases.

Regarding a possible merge to master, there is a few problems. These chips use nested JTAG TAPs which does match at all the way OpenOCD describe them. I just hardcoded everything in the chip driver here but that is not very elegant. I also needed to modify common code in driver/interface/ftdi because xPC56 TAP requires to go through PAUSE-DR (or not) to reset the CPU TAP to the high level one.

The current code is also full of dirty debug stuff, I did not even tried to clean it yet or to conform to coding style. Also, I did not always understood OpenOCD internals, so some parts are probably clumsy.

My work obligations do not let me much time to invest on this project so cleanup/improvement/support would be quite difficult. From the discussion we had a few months ago I do not think there is a lot of demand for open source tools on these chips, so more investment might not be worth. However I hope this work can still be useful to other peoples.

Antoine