segger embedded studio data breakpoints expressions nRF52833

[Learner]

Hello,

I am trying to set a data breakpoint expression on a global array or global variable  but I don't seem to be able to.

Each time I set a data breakpoint I get a '?' next to the breakpoint. See attached picture.

uint8_t ble_ad[HB_BLE_AD_BUFF_SIZE_MAX].

I am using segger Embedded Studio v5.60 and nRF52833 SoC.

Thank you.

Kind regards

Mohamed

[Learner]

Good Morning Vidar,

Vidar Berg said:

The stack area allocated to each thread can be found in the map file.

I am attaching my map file please let me know where the stack area is.

/cfs-file/__key/communityserver-discussions-components-files/4/2437.zephyr.map

Vidar Berg said:

If you are unsure if it is enabled, you can check if CONFIG_MPU_STACK_GUARD=y

It is already enabled in my .config file and this is the error I am getting. There is no mention of stack overflow violation but I am suspecting there is. So, what else could be causing this fault ?

[00:19:08.163,787] \033[1;31m<err> os: ***** MPU FAULT *****\033[0m
[00:19:08.163,787] \033[1;31m<err> os: Instruction Access Violation\033[0m
[00:19:08.163,787] \033[1;31m<err> os: r0/a1: 0x00000000 r1/a2: 0x2000cfc0 r2/a3: 0x2000cfc0\033[0m
[00:19:08.163,787] \033[1;31m<err> os: r3/a4: 0x200042ff r12/ip: 0x000000e2 r14/lr: 0x00010cff\033[0m
[00:19:08.163,818] \033[1;31m<err> os: xpsr: 0x60000000\033[0m
[00:19:08.163,818] \033[1;31m<err> os: Faulting instruction address (r15/pc): 0xeb699002\033[0m
[00:19:08.163,818] \033[1;31m<err> os: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0\033[0m
[00:19:08.163,818] \033[1;31m<err> os: Current thread: 0x20001f40 (sysworkq)\033[0m
[00:19:09.107,147] \033[1;31m<err> os: Halting system\033[0m

I have enabled the STACK_ANALYZER and I am attaching the stack analyzer logs from boot up to the "MPU FAULT" crash. Note, where you see the three dots (...)  is where I removed my application logs (LOG_DBG/INF/WRN/ERR) for readability.

stack_analyzer_logs.txt

Thank you

Kind regards

Mohamed

[Vidar Berg]

Hi Mohamed,

The map file did not get uploaded. Anyway, the easiest way to try to rule out a stack overflow is often to try increasing the stack size, or have you tried that already? The sysworkq stack can be adjusted through the CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE symbol.

Kind regards,

Vidar

[Learner]

Good Morning Vidar,

Vidar Berg said:

The map file did not get uploaded.

Here it is again.

/cfs-file/__key/communityserver-discussions-components-files/4/1106.zephyr.map

Vidar Berg said:

Anyway, the easiest way to try to rule out a stack overflow is often to try increasing the stack size, or have you tried that already?

Did you have a look at the stack analyzer log file stack_analyzer_logs.txt I attached as a link in my previous message? there is nothing in the logs that suggest the stack is overflowing. Please have a look.

Kind regards

Mohamed

[Vidar Berg]

Hi Mohamed,

The system workqueue stack is here:

.noinit."WEST_TOPDIR/zephyr/kernel/system_work_q.c".0
0x2000d760 0x820 zephyr/kernel/libkernel.a(system_work_q.c.obj)

Learner said:

Did you have a look at the stack analyzer log file stack_analyzer_logs.txt I attached as a link in my previous message? there is nothing in the logs that suggest the stack is overflowing. Please have a

I did, and I am not saying a believe it is a stack overflow. My suggestion was in response to your comment here: 

Learner said:

There is no mention of stack overflow violation but I am suspecting there is.

Kind regards,

Vidar

[Learner]

Good Morning Vidar,

The root cause of the MPU FAULT I was getting is an index that went astray and caused a buffer overflow. I would have thought the tools would have reported a BUFFER OVERFLOW error instead.

So, although I managed to find the bug in my firmware I am still interested in your answer to my previous question,

Learner said:

please help me find where the stack starts and whether it builds up or down.

I would appreciate it if you could answer it or point me to a document that describes this.

Thank you for your support over the last 10 days or so.

Kind regards

Mohamed