Quality RTOS & Embedded Software

 Real time embedded FreeRTOS RSS feed 
Real time embedded FreeRTOS mailing list 
Quick Start Supported MCUs PDF Books Trace Tools Ecosystem TCP & FAT Training




Loading

PIC32 Application using queue crashes

Posted by Kevin on November 1, 2012
Hi everybody,

I am facing a problem with PIC32 port when I try to use queues. I got a simple application, only one task, one queue. There are correctly initialised (task and queue handles aren't null), vTaskStartScheduler() is called, then my task tries to receive a message from the queue with xQueueReceive().

I get stuck in vListInsert(), but :

1. My stack task doesn't overflow (I use method 2 for stack checking and vApplicationStackOverflowHook() is never called)

2. I don't think I have trouble with interrupts priorities : Kernell priority is 1, max interrupt priority is set to 4. Plus, I don't have used any other interrupts than those used for the kernell.

3. When xQueueReceived() is called, the scheduler is running (xSchedulerRunning = 1 and uxSchedulerSuspended = 0) but in vListInsert(), scheduler is suspended (is that ok ?). Actually it is suspended when calling vTaskSuspendAll in xQueueGenericReceive().

4. Queue has been initialised, no pending message.

Then, a bus exception is thrown (DBE). I have the same problem if I create a second task that put a message into the queue.

If it could help, I am using XC32 v1.11. I can reproduce the problem with MPLAB Sim and when I am debugging with a Digilent Cerebot MX7ck board with built-in licensed debugger.

RE: PIC32 Application using queue crashes

Posted by Dave on November 1, 2012
As your application is so small, please post the code. Make sure to enclose it with the Codify Text tags (button just above the text entry box in the forum).

RE: PIC32 Application using queue crashes

Posted by Kevin on November 2, 2012
- Main():

int main(void) 
{
vSetupHardware();

Create_Ressources_OSTracing();

vTaskStartScheduler();

return 0;
}


- Create_Ressources_OSTracing():

ErrorCode_t Create_Ressources_OSTracing (void)
{
ErrorCode_t ErrorCode = {0};
#ifdef OS_TRACE
// 1. Create Task
if((ErrorCode.Code&ERRCODEMASK) == CODE_000_NO_ERROR)
{
if(xTaskCreate(_OS_Trace_TaskHandler,
"RTOS Trace Task",
STACKSIZE_OS_TRACE,
NULL,
PRIORITY_OS_TRACE,
&TASK_OSTracing) != pdPASS)
{
ErrorCode.Code = LAYER_Service | TASKID_OSTrace | CODE_002_MEMORY_ALLOCATION_ERROR;
}
}

// 2. Create Message to Send Queue
if((ErrorCode.Code&ERRCODEMASK) == CODE_000_NO_ERROR)
{
Q_OSTracing = xQueueCreate(MAX_MSG_Q_OS_TRACE, sizeof(OS_TRACE_Msg_t));
if(Q_OSTracing == NULL)
{
ErrorCode.Code = LAYER_Service | TASKID_OSTrace | CODE_002_MEMORY_ALLOCATION_ERROR;
}
else
{
#if __DEBUG
vQueueAddToRegistry(Q_OSTracing, "OS Tracing Queue");
#endif
}
}
#endif
return ErrorCode;
}


- The task - _OS_Trace_TaskHandler():

void _OS_Trace_TaskHandler (void * pvTaskParam)
{
OS_TRACE_Msg_tTraceMsg;
OS_TRACE_Time_tTraceTime;

vTaskDelayMs(2000);

while(1)
{
if(xQueueReceive(&Q_OSTracing, &TraceMsg, portMAX_DELAY) == pdPASS)
{
if(TraceMsg.DateFlag)
{
_OS_Trace_GetTime(&TraceTime);
_OS_Trace_FormatTime(&TraceTime, &TraceMsg);
}

_OS_Trace_LogTrace(&TraceMsg);
}
}
}


vTaskDelayMs() is a macro that calls vTaskDelay and converts parameter in ms to ticks with portTICK_RATE_MS.

RE: PIC32 Application using queue crashes

Posted by Richard on November 2, 2012
I'm curious why you test

if((ErrorCode.Code&ERRCODEMASK) == CODE_000_NO_ERROR)


when ErrorCode is a local variable and just been initialised so can't hold any value other than 0, but that is probably not relevant.

What is probably relevant is the following call:

if(xQueueReceive(&Q_OSTracing, &TraceMsg, portMAX_DELAY) == pdPASS)


You don't show the definition of Q_OSTracing, but I suspect you don't need the '&' in front of it.

If you declare it as:

xQueueHandle Q_OSTracing;


...and it the queue has been created, then you can read from it using:

xQueueReceive(Q_OSTracing, &TraceMsg, portMAX_DELAY);


As you are using portMAX_DELAY, you only need to test the return value if INCLUDE_vTaskSuspend is not set to 1 in FreeRTOSConfig.h. That is because if INCLUDE_vTaskSuspend is set to one portMAX_DELAY will act as an indefinite wait.

Regards.

RE: PIC32 Application using queue crashes

Posted by Kevin on November 2, 2012
“when ErrorCode is a local variable and just been initialised so can't hold any value other than 0, but that is probably not relevant.”


Yes it is, actually it's more a "way" that I try to respect, I agree this test isn't usefull ;)

“What is probably relevant is the following call: [...] You don't show the definition of Q_OSTracing, but I suspect you don't need the '&' in front of it. If you declare it as:
xQueueHandle Q_OSTracing;”


Exact ! I'm more familiar with EmbOS from Segger, in which queue type is a structure, not a handle, which is actually just a void pointer ... I made the same mistake when I wanted to put a message into the queue :

if(xQueueIsQueueFullFromISR(Q_OSTracing) != pdFALSE)
{
xQueueSend(&Q_OSTracing, &TraceMsg, MS_TO_TICK(50));
}


That's why I got troubles in sending messages too.

“As you are using portMAX_DELAY, you only need to test the return value if INCLUDE_vTaskSuspend is not set to 1 in FreeRTOSConfig.h. That is because if INCLUDE_vTaskSuspend is set to one portMAX_DELAY will act as an indefinite wait.”


Yes, my task is suspended. I will let the test because this task maybe be used with different configuration of FreeRTOS, it is some kind of generic method to trace OS and application events for a few different FreeRTOS based softwares.

Anyway, thank you for your help !


[ Back to the top ]    [ About FreeRTOS ]    [ Sitemap ]    [ ]




Copyright (C) 2004-2010 Richard Barry. Copyright (C) 2010-2016 Real Time Engineers Ltd.
Any and all data, files, source code, html content and documentation included in the FreeRTOSTM distribution or available on this site are the exclusive property of Real Time Engineers Ltd.. See the files license.txt (included in the distribution) and this copyright notice for more information. FreeRTOSTM and FreeRTOS.orgTM are trade marks of Real Time Engineers Ltd.

Latest News:

FreeRTOS V9.0.0 is now available for download.


Free TCP/IP and file system demos for the RTOS


Sponsored Links

⇓ Now With No Code Size Limit! ⇓
⇑ Free Download Without Registering ⇑


FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

Renesas Electronics Gold Alliance RTOS Partner.jpg

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers

Atmel RTOS partner supporting ARM Cortex-M3 and AVR32 microcontrollers

STMicro RTOS partner supporting ARM7, ARM Cortex-M3, ARM Cortex-M4 and ARM Cortex-M0

Xilinx Microblaze and Zynq partner

Silicon Labs low power RTOS partner

Altera RTOS partner for Nios II and Cortex-A9 SoC

Freescale Alliance RTOS Member supporting ARM and ColdFire microcontrollers

Infineon ARM Cortex-M microcontrollers

Texas Instruments MCU Developer Network RTOS partner for ARM and MSP430 microcontrollers

Cypress RTOS partner supporting ARM Cortex-M3

Fujitsu RTOS partner supporting ARM Cortex-M3 and FM3

Microsemi (previously Actel) RTOS partner supporting ARM Cortex-M3

Atollic Partner

IAR Partner

Keil ARM Partner

Embedded Artists