Breakpoints not being hit

[nrbrook]

I'm compiling a custom application using the CMake scripts in the nRF mesh SDK. When I debug the application, even though the debugger is working – I can pause execution – breakpoints are not being hit. I wondered if it is perhaps because the breakpoints are not being set for the correct memory location, but I'm not sure how I could check that.

In addition, when I place a breakpoint, execution is immediately paused (SIGTRAP, but not where I placed the breakpoint), it would be good to know how to prevent this.

Here is the output from JLinkGDBServer when a breakpoint is set on the first line of main():

/usr/local/bin/JLinkGDBServer -device nrf52 -strict -timeout 0 -nogui -if swd -speed 1000 -endian little
SEGGER J-Link GDB Server V6.44h Command Line Version

JLinkARM.dll V6.44h (DLL compiled May  3 2019 17:40:32)

Command line: -device nrf52 -strict -timeout 0 -nogui -if swd -speed 1000 -endian little
-----GDB Server start settings-----
GDBInit file:                  none
GDB Server Listening port:     2331
SWO raw output listening port: 2332
Terminal I/O port:             2333
Accept remote connection:      yes
Generate logfile:              off
Verify download:               off
Init regs on start:            off
Silent mode:                   off
Single run mode:               off
Target connection timeout:     0 ms
------J-Link related settings------
J-Link Host interface:         USB
J-Link script:                 none
J-Link settings file:          none
------Target related settings------
Target device:                 nrf52
Target interface:              SWD
Target interface speed:        1000kHz
Target endian:                 little

Connecting to J-Link...
J-Link is connected.
Error during pretty printers setup: Undefined info command: "pretty-printer".  Try "help info".

Some features and performance optimizations will not be available.

Firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Jan  7 2019 14:07:15
Hardware: V1.00
S/N: 682644303
Checking target voltage...
Target voltage: 3.30 V
Listening on TCP/IP port 2331
Connecting to target...Connected to target
Waiting for GDB connection...Connected to 127.0.0.1
Reading all registers
Reading 64 bytes @ address 0x00027A80
Read 4 bytes @ address 0x00027BA8 (Data = 0x20004998)
Read 2 bytes @ address 0x00027B8A (Data = 0x4669)
Reading 64 bytes @ address 0x000262C0
Read 4 bytes @ address 0x000262F0 (Data = 0x00045E5C)
Read 2 bytes @ address 0x000262DA (Data = 0x4B05)
Read 4 bytes @ address 0x00029AC2 (Data = 0x3007F89D)
Read 4 bytes @ address 0x00029EA8 (Data = 0xE8BDB004)
Debugger connected to tcp:localhost:2331
Setting breakpoint @ address 0x000262DA, Size = 2, BPHandle = 0x0001
Setting breakpoint @ address 0x00027B8A, Size = 2, BPHandle = 0x0002
Starting target CPU...

Also related, the breakpoint in main is hit when another problem occurs: devzone.nordicsemi.com/.../sigtrap-on-sd_softdevice_enable

I'm wondering if breakpoints are not being hit because they are not being offset by the softdevice length? In the output above a breakpoint is set at 0x000262DA, but the flash start is 0x00026000 and the soft device hex is >400kb.

[Susheel Nuguru]

I find Ozone more convenient than using GDB, can you give it a try to see if it gives you more information on call stack when you get the SIGTRAP? 

[nrbrook]

Are there any instructions for using Ozone with Nordic nRF52832?

[Susheel Nuguru]

This thread shows you how to start Ozone debugger

[nrbrook]

Thanks, I'm having difficulty connecting though.

File.NewProjectWizard();
Project.SetDevice ("nRF52832_xxAA");
Project.SetHostIF ("USB", "");
Project.SetTargetIF ("JTAG");
Project.SetTIFSpeed ("1 MHz");
Project.AddSvdFile ("$(InstallDir)/Config/CPU/Cortex-M4F.svd");
File path resolved: "$(InstallDir)/Config/CPU/Cortex-M4F.svd" was found at "/Applications/SEGGER/Ozone/Ozone.app/Contents/MacOS/Config/CPU/Cortex-M4F.svd"
File.Open ("/Users/nick/Documents/Repos/AirTurnFirmwareV2/cmake-build-debug-arm-none-eabi/src/AirTurnFirmwareProject_BT200.elf");
File.Open: completed in 400 ms
Debug.Start();
Device "NRF52832_XXAA" selected.
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
Connection failed

I know it recognises the connected nrf52DK as it displays the license warning with the JLink serial number, and I can connect with JLinkExe.

Edit: Ahh, I was using JTAG instead of SWD.