hi Mike

I am compiling , running and debugging a program generated from the same source code on ARMv7 and ARMv8 processors. when a breakpoint is hit, I am using the traces  to reconstruct the execution flow.

I noticed that on stm32 the decoder emits the address of the breakpoint in an OCSD_GEN_TRC_ELEM_INSTR_RANGE twice (before and after the exception), whereas it emits it only once (after the exception).

I need to have different handling according to the situation.

what can I use to distinguish both cases and handle the traces properly:

- the ETM version (v3.x vs v4.x)

- the CPU architecture (Cortex A v7 vs cortex A v8)

- the ISA of executed program (A64 vs (A32 or T32 ))

- the exception number

below are the logs

on stm32MP1 (ARMv7, cortex A7)

[btrace] ETM trace_element: index= 12, channel= 0x10, OCSD_GEN_TRC_ELEM_INSTR_RANGE(exec range=0x103f4:[0x103f6] num_i(1) last_sz(2) (ISA=T32) E --- )
[btrace] ETM trace_element: index= 13, channel= 0x10, OCSD_GEN_TRC_ELEM_EXCEPTION(excep num (0x09) )
[btrace] ETM trace_element: index= 54, channel= 0x10, OCSD_GEN_TRC_ELEM_TRACE_ON( [begin or filter])
[btrace] ETM trace_element: index= 54, channel= 0x10, OCSD_GEN_TRC_ELEM_PE_CONTEXT((ISA=T32) N; 32-bit; )
[btrace] ETM trace_element: index= 60, channel= 0x10, OCSD_GEN_TRC_ELEM_INSTR_RANGE(exec range=0x103f4:[0x103f6] num_i(1) last_sz(2) (ISA=T32) E --- )

on qcom APQ8016e(ARMv8, Cortex A53)

[btrace] ETM trace_element: index= 38, channel= 0x12, OCSD_GEN_TRC_ELEM_INSTR_RANGE(exec range=0x4005b4:[0x4005b8] num_i(1) last_sz(4) (ISA=A64) E --- )
[btrace] ETM trace_element: index= 38, channel= 0x12, OCSD_GEN_TRC_ELEM_EXCEPTION(pref ret addr:0x4005b8; excep num (0x06) )
[btrace] ETM trace_element: index= 112, channel= 0x16, OCSD_GEN_TRC_ELEM_NO_SYNC( [init-decoder])
[btrace] ETM trace_element: index= 138, channel= 0x16, OCSD_GEN_TRC_ELEM_TRACE_ON( [begin or filter])
[btrace] ETM trace_element: index= 139, channel= 0x16, OCSD_GEN_TRC_ELEM_PE_CONTEXT((ISA=A64) EL0N; 64-bit; )
[btrace] ETM trace_element: index= 150, channel= 0x16, OCSD_GEN_TRC_ELEM_INSTR_RANGE(exec range=0x4005b8:[0x4005bc] num_i(1) last_sz(4) (ISA=A64) E BR  )

Kind Regards

Zied Guermazi