Issues Debugging FreeRTOS with J-Link

[Artur Vieira]

Having some issues trying to debug a FreeRTOS project using JLink, using an STM32U5G9 (Riverdi 5" Display Board)

 

If I enable "serverRtos" in the launch configuration:

"configurations": [
 {
 "type": "jlinkgdbtarget",
 "request": "launch",
 "name": "STM32Cube: STM32 Launch JLink GDB Server",
 "origin": "snippet",
 "cwd": "${workspaceFolder}",
 "preBuild": "${command:st-stm32-ide-debug-launch.build}",
 "runEntry": "main",
 "serverSpeed": "12000",
 "serverRtos": {
 "enabled": true,
 "port": "60000",
 "driver": "freertos",
 "driverPort": "ARM_CM33_NTZ"
 },
 "preRunCommands": [
 "monitor exec SetRTTSearchRanges 0x200bb800 0x234800" 
 ],
 "imagesAndSymbols": [
 {
 "imageFileName": "${command:st-stm32-ide-debug-launch.get-projects-binary-from-context1}"
 }
 ]
 }
 ]

And then try to start a debug session, i get a disconnect error:

Reading 20 bytes @ address 0x200C2A5C
Read 4 bytes @ address 0x200C2A28 (Data = 0x200C2970)
Read 4 bytes @ address 0x200C2A58 (Data = 0x200BEA20)
Read 4 bytes @ address 0x200C2A6C (Data = 0x200C2A18)
Reading 16384 bytes @ address 0x200BEA20
RTOS proxy: Missing symbol: pxCurrentTimerList.
Lost connection to GDB Server
Read 4 bytes @ address 0x200C2A78 (Data = 0x00000018)
GDB closed TCP/IP connection (Socket 1028)
{"label":"","value":[{"label":"Driver","value":"freeRTOS"},{"label":"Kernel state","value":"Started"}]}
RTOS proxy: Proxy stopped.
RTOS proxy: C:\Users\artur\AppData\Local\stm32cube\bundles\rtos-proxy\0.17.0+st.3\bin\RtosProxy has exited with code 0Remote communication error. Target disconnected: error while reading: No error.
GDB response with no command: 14
Restoring target state and closing J-Link connection...
Shutting down...
cube has exited with code 0

 

It complains about not finding "pxCurrentTimerList" although it is present in the map file (I even created a rtos timer on purpose to make sure that there where timers in use).

 

Already using J-Link bundle pack 8.38.0+st.1 as recommended by https://community.st.com/t5/stm32cubeide-for-visual-studio/cannot-start-rtos-aware-debug-session-using-j-link/m-p/870735/highlight/true#M1827.

 

Also added the code suggestion indicated in https://community.st.com/t5/stm32cubeide-for-visual-studio/stm32cube-rtos-state-not-showing-all-queues-semaphores/m-p/865915/highlight/true#M1708 since initially was also complaining about missing "xQueueRegistrySize".

 

The processor I am using is a STM32U5G9, does the "serverRtos" has a limitation on the RAM range where it tries to fetch this kind of data? Something similar to an issue with Segger RTT that the auto-discovery of RTT Block is limited in range by default. This because at the moment I am reserving a big block of RAM starting at base address for the display buffer.

 

Thank You

 

 

[Florent V]

Hi @Artur Vieira,

Could you please add the following attribute to check if the error message becomes more detailed?

"verbose": true

And also, in a second test, disable the serverRtos to check if the issue persists.

Best Regards,
/Flo

[Artur Vieira]

---

Could you please add the following attribute to check if the error message becomes more detailed?

"verbose": true

 

---

@Florent V I have tried enabling "verbose", the error is more os less the same:

To client: {"seq":0,"type":"event","event":"output","body":{"category":"proxy","output":"RTOS proxy: Missing symbol: pxCurrentTimerList.\r\n"}}
RTOS proxy: Missing symbol: pxCurrentTimerList.
To client: {"seq":0,"type":"event","event":"output","body":{"category":"proxy","output":"RTOS proxy: Lost connection to GDB Server\r\n"}}

 In attachment the full log output.

The variable "pxCurrentTimerList" is defined at the following address according to "arm-none-eabi-nm.exe" parsing the elf file...

20020f08 B pxCurrentTimerList

And it's also visible in the "map" file:

 .bss.pxCurrentTimerList
 0x20020f08 0x4 cmake/stm32cubemx/CMakeFiles/RTOS2.dir/__/__/Middlewares/Third_Party/FreeRTOS/Source/timers.c.obj
 0x20020f08 pxCurrentTimerList

 

---

And also, in a second test, disable the serverRtos to check if the issue persists.

Yes, if I disable the serverRtos, the debug session starts normally, obviously without the RTOS information.

 

Thank You

[Florent V]

Hi @Artur Vieira,

Thank you for the log.
Indeed, the error is not more explicit.
So far, I have not been able to reproduce it on my side. 
Even though the variable seems well defined, I wonder if it might be the cause of the issue or at least producing a side effect.
Would it be possible to share the project or a lightweight version ?

Kind Regards,
/Flo