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authorPaul Selkirk <paul@psgd.org>2017-05-06 13:07:59 -0400
committerPaul Selkirk <paul@psgd.org>2017-05-06 13:07:59 -0400
commit4d69f1a0ef2ef3aa23b0ac9f1b9cbc84582136a7 (patch)
tree11fa3e8110ed726aca09ce8fb956fc547d2e9e7a
parent1815f1b2aa0a3ff0654f4eb65fdd0a5bdfe8c7b7 (diff)
Correct offset to get the PC.
A previous version of this code ran over the RTOS, where threads used the Process Stack, while the SysTick interrupt used the Main Stack. Now everything's on the main stack, so we need to account for 2 extra words that SysTick_Handler pushes on the stack at entry.
-rw-r--r--libraries/libprof/README.txt4
-rw-r--r--libraries/libprof/profil.c2
2 files changed, 3 insertions, 3 deletions
diff --git a/libraries/libprof/README.txt b/libraries/libprof/README.txt
index da138c2..9db27a6 100644
--- a/libraries/libprof/README.txt
+++ b/libraries/libprof/README.txt
@@ -53,8 +53,8 @@ In the OpenOCD console, enable semihosting:
In the CLI, type `profile start`, then start the unit test or whatever
will be exercising the hsm. Afterwards, in the CLI, type `profile stop`.
-After invoking `profile stop`, it takes almost 2 minutes to write gmon.out
-over OpenOCD to the host.
+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:
diff --git a/libraries/libprof/profil.c b/libraries/libprof/profil.c
index 07761dd..004af77 100644
--- a/libraries/libprof/profil.c
+++ b/libraries/libprof/profil.c
@@ -30,7 +30,7 @@ extern void set_SysTick_hook(void (*hook)(void));
/* sample the current program counter */
static void SysTick_hook(void) {
- size_t pc = (size_t)((uint32_t *)__get_MSP())[5];
+ size_t pc = (size_t)((uint32_t *)__get_MSP())[7];
if (pc >= prof.lowpc && pc < prof.highpc) {
size_t idx = PROFIDX (pc, prof.lowpc, prof.scale);
prof.counter[idx]++;