Jlink connection problem

Technical Support
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1

Good morning

I’ve Verdin iMX8M Mini and Verdin Development Board.
I’m using Torizon Core with Evaluation Container as image.

I’m trying to connect to the M4 core using Jlink.
I get the following error

lucavaltellina@lucavaltellina-virtual-machine:/opt/SEGGER/JLink$ ./JLinkGDBServer -if JTAG -device MIMX8MM6_M4
SEGGER J-Link GDB Server V7.94b Command Line Version

JLinkARM.dll V7.94b (DLL compiled Dec 13 2023 17:05:24)

Command line: -if JTAG -device MIMX8MM6_M4
-----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: MIMX8MM6_M4
Target device parameters: none
Target interface: JTAG
Target interface speed: 4000kHz
Target endian: little

Connecting to J-Link…
J-Link is connected.
Firmware: J-Link Lite-Cortex-M V9 compiled Feb 2 2021 16:33:27
Hardware: V9.00
S/N: 519002676
Feature(s): GDB
Checking target voltage…
Target voltage: 1.81 V
Listening on TCP/IP port 2331
Connecting to target…
ERROR: Could not connect to target.
Target connection failed. GDBServer will be closed…Restoring target state and closing J-Link connection…
Shutting down…
Could not connect to target.

2

Hello @VLengineering,

Welcome to the Toradex Community :tada: Feel free to browse around!

We were able to reproduce this error when the jumpers X67A – X67F were connected on the verdin development board. You can see on our documentation that you need to remove these jumpers for debugging. See here: Cortex-M JTAG Debugging | Toradex Developer Center

Could you please confirm if you have removed those?

3

Hi Rudhi

Yes I removed the jumpers you are talking about.
However I made a step forward…
The connection to the m4 core did not occur because the core clock was OFF as I had not loaded any firmware.
But I wanted to be able to debug without any firmware loaded!
After an analysis of the imx8mini reference manual I saw that from u-boot I can activate the m4 core clock via the command
“mw 0x3039000C AA”.
This way the connection via jlink works.

Now obviously I have to implement the management of m4 fw loading at boot following your guide.

Thanks

1 Like
4

Hello @VLengineering,

Thanks for the update! Feel free to ask if you have more questions.