I try to implement gdb-stubs for some kernel. And I can't make hardware breakpoint work on iMX6 hardware. I implement exception handlers and set up ARM debug module with next steps:
- check that debug module in normal power state and registers can be accessed;
- check that OS Lock not enabled;
- reset registers DBGVCR, DBGBCRx, DBGWCRx
- enable monitor mode;
When I set up hardware breakpoints using registers DBGBCRx, DBGBVRx they don't work. I checked this gdb-stub code on qemu and it works.
I found only a few iMX-specific options: CPU debug clocks in CCM module (enabled) and register IOMUXC_GPR10 (debug enabled)
Do I miss something in the iMX-specific configuration of debug module?