hi all

I am announcing updates in the implementation of branch tracing using coresight etm in GDB. in this update, functions and instruction history are running successfully on single threaded applications. reverse debugging is basically working with the limitation that sometimes cspr register (register 25) is required but current implementation does not provide it.

the feature requires linux kernel v 4.19 or higher with manual etm sink setup. 5.9.1 or higher for automatic sink selection.

GDB gdb.btrace test suite was adapted to run on arm processors. here is the summary of the gdb.btrace test results executed on an STM32MP157 (ARM cortex A7) with Linux kernel 5.9.1

=== gdb Summary ===

# of expected passes        390 # of unexpected failures    119 # of unsupported tests        4

following tests are 100% successful:

- buffer-size

- enable

- instruction_history

- function_call_history

- data

- delta

- cpu

- gcore

- record_goto-step

- dlopen

- vdso

- segv

GDB source code is available on https://github.com/gzied/binutils-gdb/tree/gdb_arm_coresight

many thanks to GDB and linaro communities for their support

Kind Regards

Zied Guermazi