[OpenOCD-devel] NRF52840 approtect erase and unlock

[Pieter De G. <pie...@gm...>]

Hi,

The following commit adds nrf52_recover to erase and unlock nrf52 APPROTECT
https://sourceforge.net/p/openocd/code/ci/73a5f58adba73306b08b7bb22ff8a9511e79869f/

However this doesn't seem to work for my nrf52840.
There are multiple issues:

   - Several calls are done to *ocd_$dap* which isn't a valid command, just
   use *$dap*
   - *apreg 1 8* is read-only, but is written
   - *ERASEALLSTATUS* is compared to 1, while 0 is the value for ready

I used the datasheet
https://infocenter.nordicsemi.com/pdf/nRF52840_PS_v1.1.pdf to verify the
values.

I think http://openocd.zylin.com/#/c/5384/ is closer to a solution.

Changing all this, however, still doesn't allow me to unlock the controller
as it restarts with approtect still active. Any suggestions on how to
proceed and debug?

Thanks in advance,
With kind regards,
Pieter