path: root/libraries/libprof/README.md

   
Profiling the Cryptech Alpha
Origin
This code was copied from https://github.com/ErichStyger/mcuoneclipse.git,
directory Examples/KDS/FRDM-K64F120M/FRDM-K64F_Profiling/Profiling, commit
9b7eedddd8b24968128582aedc63be95b61f782c, dated Mon Jan 9 16:56:17 2017 +0100.
References
I recommend reading both of these to understand how the profiling code works.


Tutorial: Using GNU Profiling (gprof) with ARM Cortex-M


Semihosting with ARM, GCC, and OpenOCD


How to build
From the top level, run
$ make DO_PROFILING=1 hsm


By default, all code is profiled, except the profiling code itself,
because that would cause fatal recursion.
How to run
You need to start OpenOCD on the host, and enable semihosting, at least
before you try to use it as a remote file system.
I recommend executing the following in the projects/hsm directory, so that
gmon.out ends up in the same directory as hsm.elf.
Start the debugger:
$ ../../bin/debug hsm


In another window, connect to OpenOCD:
$ telnet localhost 4444


In the OpenOCD console, enable semihosting:
> arm semihosting enable
> exit


Then connect to the Cryptech management console:
$ cryptech_console


In the Cryptech console, type profile start, then start the unit test or
whatever will be exercising the hsm. Afterwards, in the console, type
profile stop.
After invoking profile stop, it can take several minutes to write
gmon.out over OpenOCD to the host.
In the projects/hsm directory, run gprof to analyse the gmon.out file:
$ gprof hsm.elf >gprof.txt