RE: Having trouble using openocd with the nrf52 on OSX

Stian Røed Hafskjold — Mon, 20 Jul 2020 06:44:14 GMT

Thanks a lot!

RE: Having trouble using openocd with the nrf52 on OSX

tlongeri — Sun, 19 Jul 2020 19:14:08 GMT

I know this is an old question, but I had the same "invalid subcommand" problem when flashing so I figured I'd write something.

The short answer is the solution is to use the latest commit on the OpenOCD repo (as of writing this the latest release is v0.10.0 but it doesn't have full support for the nRF52). When you asked the question 2 years ago, ubicore's OpenOCD patch would've probably solved this issue.

The long answer is that nrf52.cfg is missing the "flash bank" command, which you need to run before running some subcommands like "write_image". If you look at nrf51.cfg, you will find these lines:

flash bank $_CHIPNAME.flash nrf51 0x00000000 0 1 1 $_TARGETNAME
flash bank $_CHIPNAME.uicr nrf51 0x10001000 0 1 1 $_TARGETNAME

Note that one of the parameters is "nrf51" - this is the name of the flash driver. Flash drivers can be found in the repo under src/flash/nor (at least in the latest OpenOCD versions), where you will find C source files that define "flash_driver" structures with a "name" member variable identifying the driver. Unfortunately, in version 0.10.0 and earlier there is no driver for the nRF52 (the "nrf51" driver might work with some limitations, I haven't tested it). The latest commit has the "nrf5" driver which works with the nRF52.

RE: Having trouble using openocd with the nrf52 on OSX

Maipei — Fri, 13 Jul 2018 13:44:10 GMT

So I never found a way to make the above work, but I found that calling openocd as a bare command worked just fine, after which I could jump into the connection with a telnet session and use gdb to do the debugging that I want to do.