December 28, 2020

STM32H743 "horse pill" -- STLink V3

The Nucleo-144 has STLink V3 built in! A micro USB connector is provided and it seems that this is adequate to power the board.

STLink V3 is quite different from the V2 I am used to. My V2 probes support the 4 wire SWD connector and I use OpenOCD with them. The STLink V3 provides two (maybe more?) USB devices, one is a serial console (VCP), which is a nice idea. I can use one cable both for a serial console and to download firmware with no fiddling required on my part.

According to this post, OpenOCD supports the V3 as of 2018-10-09.

I am running "Open On-Chip Debugger 0.10.0" from the Fedora DNF repository. But my files in /usr/share/openocd/scripts/interface are not as he shows. I see:
ls -l stlink*
-rw-r--r-- 1 root root 156 Jan 22  2017 stlink-v1.cfg
-rw-r--r-- 1 root root 488 Jan 22  2017 stlink-v2-1.cfg
-rw-r--r-- 1 root root 484 Jan 22  2017 stlink-v2.cfg

Get the latest openocd files

The sources are kept on sf.net under git, so I do this:
git clone https://git.code.sf.net/p/openocd/code openocd-code

And this does contain the stlink.cfg file rather than the 3 separate files shown above.

So the problem is that the openocd maintainers are changing their source tree without bumping the version number. I have a source tree that claims to be 0.10.0 from back in January 2017 that does not have the stlink.cfg file for V3. Fedora apparently assumes (just as I would) that they have the current version and no changes are being made.

The question is whether I will need to do a full rebuild or simply download the rather simple unified stlink.cfg file.


Feedback? Questions? Drop me a line!

Tom's Computer Info / tom@mmto.org