I'm using SABRE iMX7D board, with default Linux BSP and FreeRTOS BSP and examples, as provided by NXP.
When trying to connect to and debug on M4 core, or when just trying to connect to the A7 core (not do anything but connect.) with HW JTAG debugger, I've encountered problem doing so if Linux (default image as provided by NXP with the board) is booted:
- I get errors trying to connect to the core - both, either M4, or A7 (core 0, primary). Seems random, on some occasions it may connect, mostly fails, error of the sort ' cannot halt the core' or 'cannot connect to the core.'
The entire SoC (or A7) may get re-set / rebooted with some connect attempts and/or firmware uploads on M4 core.
- Nothing of the sort seems to happen if I try to debug / run M4 code with debugger when only u-boot has booted, pre-Linux.
Anyone else has had this issue? Is there a config problem with Linux kernel interfering with JTAG interface? Or some sharing problem between the M4 and A7?