Can't debug the system with jlink

[levijo]

I have tried to debug my nordic5340 with VS code and it fails to load the code, although I'm able to flash the code using vs code.

when trying to track the problem using the Jlink commander I get a message the jlink fails to connect as my device is secured.

It offers to unsecure the board but that doesn't work.

see below logs:

SEGGER J-Link Commander V8.12d (Compiled Jan 29 2025 13:07:00)
DLL version V8.12d, compiled Jan 29 2025 13:06:04

Connecting to J-Link via USB...O.K.
Firmware: J-Link V12 compiled Dec 4 2024 17:53:50
Hardware version: V12.00
J-Link uptime (since boot): 0d 00h 01m 55s
S/N: 52003290
License(s): GDB
USB speed mode: High speed (480 MBit/s)
VTref=1.812V

Type "connect" to establish a target connection, '?' for help
J-Link>connect
Please specify device / core. <Default>: CORTEX-M33
Type '?' for selection dialog
Device>?
Please specify target interface:
J) JTAG (Default)
S) SWD
T) cJTAG
TIF>JTAG
Device position in JTAG chain (IRPre,DRPre) <Default>: -1,-1 => Auto-detect
JTAGConf>
Specify target interface speed [kHz]. <Default>: 4000 kHz
Speed>4000
Device "NRF5340_XXAA_APP" selected.

Connecting to target via JTAG
ConfigTargetSettings() start
ConfigTargetSettings() end - Took 23us
InitTarget() start
Device will be unsecured now.
InitTarget() end - Took 11.2s
Connect failed. Resetting via Reset pin and trying again.
ConfigTargetSettings() start
ConfigTargetSettings() end - Took 8us
InitTarget() start
Device will be unsecured now.
InitTarget() end - Took 2.31s
Error occurred: Could not connect to the target device.
For troubleshooting steps visit: wiki.segger.com/J-Link_Troubleshooting
J-Link>

[Elfving]

Hi again Joshua,

Does recovering or "erasing all" help? Do you have all the switches on the board on the board in the default position?

Regards,

Elfving

[levijo]

Hi Elfving,

This debug is working in the evaluation board; its our board, which is based on nRF5340 MCU that I can't connect with a debugger. Flashing with the VS code is working well but it seems like some security locks not allowing to connect with the J-link.

[levijo]

also recovering helps when the device program fails, but the connection to the j-link for debugging always fails

[levijo]

sometimes the debug console shows the following logs, which implies that the jlink debug server was able to connect but vs code doesn't show anything on the IDE:

JLinkGDBServerCL: SEGGER J-Link GDB Server V8.12d Command Line Version
JLinkGDBServerCL: 
JLinkGDBServerCL: JLinkARM.dll V8.12d (DLL compiled Jan 29 2025 13:06:04)
JLinkGDBServerCL: 
JLinkGDBServerCL: -----GDB Server start settings-----
JLinkGDBServerCL: GDBInit file:                  none
JLinkGDBServerCL: GDB Server Listening port:     57568
JLinkGDBServerCL: SWO raw output listening port: 2332
JLinkGDBServerCL: Terminal I/O port:             2333
JLinkGDBServerCL: Accept remote connection:      localhost only
JLinkGDBServerCL: Generate logfile:              off
JLinkGDBServerCL: Verify download:               off
JLinkGDBServerCL: Init regs on start:            off
JLinkGDBServerCL: Silent mode:                   on
JLinkGDBServerCL: Single run mode:               on
JLinkGDBServerCL: Target connection timeout:     0 ms
JLinkGDBServerCL: ------J-Link related settings------
JLinkGDBServerCL: J-Link Host interface:         USB
JLinkGDBServerCL: J-Link script:                 none
JLinkGDBServerCL: J-Link settings file:          none
JLinkGDBServerCL: ------Target related settings------
JLinkGDBServerCL: Target device:                 nrf5340_xxaa_app
JLinkGDBServerCL: Target device parameters:      none
JLinkGDBServerCL: Target interface:              SWD
JLinkGDBServerCL: Target interface speed:        12000kHz
JLinkGDBServerCL: Target endian:                 little
JLinkGDBServerCL: 
=thread-group-added,id="i1"
=cmd-param-changed,param="pagination",value="off"
arch_cpu_atomic_idle (key=32) at C:/Repos/Genio2.2/genio-worskpace/zephyr/arch/arm/core/cortex_m/cpu_idle.c:131
131		SLEEP_IF_ALLOWED(__WFE);

[Elfving]

Looks like approtect being enabled is the issue.

You can disable that to debug it, though how you do it depends a bit on the NCS version. And you'll have to do it for both the netcore and appcore for the nRF5340. What NCS version are you using?

Regards,

Elfving

[levijo]

I'm using version 2.7.0

[levijo]

It also seems to me as an autoprotect issue, but in the other hand it is working well with the DK, using the same auto protection configurations

[Elfving]

I believe there are a few different ways of disabling it, and easy to miss something you need to enable it, but essentially you need to configure it to be off in both the netcore and appcore. 

What you essentially need to do is to make sure that ENABLE_APPROTECT_USER_HANDLING (and ENABLE_SECURE_APPROTECT_USER_HANDLING for the appcore) are set in the project. And then call nrf53_handle_approtect() early on it the initialization of the code. Do all of this for both the appcore and netcore code if you have custom applications running on both; if just the BLE stack is running on the netcore then just doing the appcore should be okay.

If that doesn't work, check if CONFIG_NRF_APPROTECT_USE_UICR is set.

Regards,

Elfving