can't create/run new task in demo

biker126 wrote on Friday, September 14, 2007:

hi everyone

i’ve successfully installed the “ethernet demo” for eclipse / gcc and the LPC2368. however, when i m trying to implement my own simple task (it does nothing but incrementing and resetting a counter variable) openOCD crashes a few seconds after flashing with:

Error:   armv4_5.c:186 armv4_5_mode_to_number(): invalid mode value encountered
Error:   arm7_9_common.c:1075 arm7_9_debug_entry(): cpsr contains invalid mode value - communication failure
Error:   target.c:1157 handle_target(): couldn’t poll target, exiting

so i can’t even start a GDB session to debug the program…

could anyone give me some beginners tips on what i have to focus when implementing my own code for freeRTOS?

davedoors wrote on Friday, September 14, 2007:

I presume you can successfully run the demo as it is in the download without any modification?

main() creates a lot of standard demo tasks.  In some of the demos these tasks use up all the available RTOS heap.  The size of the heap being set by parameter configTOTAL_HEAP_SIZE within FreeRTOSConfig.h.  If you run out of memory then try starting the scheduler the call to vTaskStartScheduler() will simply return and you will run off the bottom of main().

Try preventing some of the standard demo tasks from being created so you have RAM left over to create your own task.  Also try placing a null loop (while(1)) after vTaskStartScheduler() within main() so you can see if the function returns.

biker126 wrote on Saturday, September 15, 2007:

i think you are probably right (with the "not enough memory") as in some cases (when i can debug the demo) the program indeed ends up in and asm-endless-loop which is reached as far as i know by the "return 0" in main() (after the startscheduler() ).

could it also have something to do with a wrong memory map/linker script file?