Crash Log Parser Tool

This post-processing tool can be used to parse crash log generated by Mbed-OS when an exception happens.

Capturing crash log

When an exception happens Mbed-OS will print out the crash information to STDOUT. The crash information contains register context at the time exception and current threads in the system. The information printed out to STDOUT will be similar to below. Registers captured depends on specific Cortex-M core you are using. For example, if your target is using Cortex-M0, some registers like MMFSR, BFSR, UFSR may not be available and will not appear in the crash log.

++ MbedOS Fault Handler ++

FaultType: HardFault

Context: R0 : 0000AAA3 R1 : 20002070 R2 : 00009558 R3 : 00412A02 R4 : E000ED14 R5 : 00000000 R6 : 00000000 R7 : 00000000 R8 : 00000000 R9 : 00000000 R10 : 00000000 R11 : 00000000 R12 : 0000BCE5 SP : 20002070 LR : 00009E75 PC : 00009512 xPSR : 01000000 PSP : 20002008 MSP : 2002FFD8 CPUID: 410FC241 HFSR : 40000000 MMFSR: 00000000 BFSR : 00000000 UFSR : 00000100 DFSR : 00000008 AFSR : 00000000 SHCSR: 00000000

Thread Info: Current: State: 00000002 EntryFn: 0000ADF5 Stack Size: 00001000 Mem: 20001070 SP: 20002030 Next: State: 00000002 EntryFn: 0000ADF5 Stack Size: 00001000 Mem: 20001070 SP: 20002030 Wait Threads: State: 00000083 EntryFn: 0000AA1D Stack Size: 00000300 Mem: 20000548 SP: 200007D8 Delay Threads: Idle Thread: State: 00000001 EntryFn: 00009F59 Stack Size: 00000200 Mem: 20000348 SP: 20000508

-- MbedOS Fault Handler --

To generate more information copy and save this crash information to a text file and run the crash_log_parser.py tool as below. NOTE: Make sure you copy the section with text "MbedOS Fault Handler" as the this tool looks for that header.

Running the Crash Log Parser

crash_log_parser.py For example: crashlogparse.py crash.log C:\MyProject\BUILD\k64f\arm\mbed-os-hf-handler.elf C:\MyProject\BUILD\k64f\arm\mbed-os-hf-handler.map

An example output from running crash_log_parser is shown below.

Parsed Crash Info: Crash location = zero_div_test() [0000693E] Caller location = $Super$$main [00009E99] Stack Pointer at the time of crash = [20001CC0] Target/Fault Info: Processor Arch: ARM-V7M or above Processor Variant: C24 Forced exception, a fault with configurable priority has been escalated to HardFault Divide by zero error has occurred

Done parsing...