Goodmorning to all.
there are some days that I try to fix a bug in my code with FreeRTOS.
I use MPLAB X V1.90 FreeRTOS without timers . (I try with another FreeRTOS version with timer and core-modified that I found on web, but the problem s the same)
uP: PIC32MX340F032H
I use one ModBus task and one ADC task to aquire a measure with an external ADC (on SPI)
Clock:
pragma config FPLLMUL = MUL20, FPLLIDIV = DIV10, FPLLODIV = DIV_1, FWDTEN = OFF
pragma config FCKSM = CSDCMD, FPBDIV = DIV_2, OSCIOFNC = OFF, POSCMOD = HS, IESO = OFF
pragma config FSOSCEN = ON, FNOSC = PRIPLL, CP = OFF, BWP = ON
The code that I use to create the task and semaphore are:
void vCreateMBManageTask (void){ xTaskCreate( vMBProcess, "ModBusProcess", (configMINIMALSTACKSIZE)3, NULL, tskIDLEPRIORITY+2, NULL);}
void vCreateMBManageSemaphore (void){ vSemaphoreCreateBinary ( xBinaryMBManage );}
void vCreateADCManageTask (void){ xTaskCreate( vADCProcess, "ADCProcess", (configMINIMALSTACK_SIZE)3, NULL, tskIDLE_PRIORITY+1, NULL);}
void vCreateADCManageSemaphore (void){ vSemaphoreCreateBinary ( xBinaryADCManage );}
the MB process is the same:
static void vMBProcess ( void *pvParameters ){
static portTickType TaskMBManageTick = DELAY_MSEC(95);
static UCHAR *ucMBFrame;
static UCHAR ucRcvAddress;
static USHORT usLength;
static UCHAR ucFunctionCode;
static eMBException eException;
UCHAR i;
eMBEventType eEvent;
eMBErrorCode eStatus = MB_ENOERR;
xSemaphoreTake ( xBinaryMBManage, TaskMBManageTick );
for( ;; ) { if (xSemaphoreTake ( xBinaryMBManage, TaskMBManageTick ) == pdTRUE) {
.....
the FreeRTOS config is that:
#define configUSE_PREEMPTION 1
#define configUSE_IDLE_HOOK 0
#define configUSE_TICK_HOOK 0
#define configTICK_RATE_HZ ( ( portTickType ) 1000 )
#define configCPU_CLOCK_HZ ( ( unsigned long ) 25000000UL )
#define configPERIPHERAL_CLOCK_HZ ( ( unsigned long ) 25000000UL )
#define configMAX_PRIORITIES ( ( unsigned portBASE_TYPE ) 5 )
#define configMINIMAL_STACK_SIZE ( 380 )
#define configISR_STACK_SIZE ( 400 )
#define configTOTAL_HEAP_SIZE ( ( size_t ) 24000 )//( ( size_t ) 16000 )
#define configMAX_TASK_NAME_LEN ( 8 )
#define configUSE_TRACE_FACILITY 0
#define configUSE_16_BIT_TICKS 0
#define configIDLE_SHOULD_YIELD 1
#define configUSE_MUTEXES 1
#define configUSE_COUNTING_SEMAPHORES 1
//#define configCHECK_FOR_STACK_OVERFLOW 2
#define configCHECK_FOR_STACK_OVERFLOW 0
#define configQUEUE_REGISTRY_SIZE 0
/* Co-routine definitions. */
#define configUSE_CO_ROUTINES 0
#define configMAX_CO_ROUTINE_PRIORITIES ( 2 )
/* Set the following definitions to 1 to include the API function, or zeroto exclude the API function. */
#define INCLUDE_vTaskPrioritySet 1
#define INCLUDE_uxTaskPriorityGet 1
#define INCLUDE_vTaskDelete 1
#define INCLUDE_vTaskCleanUpResources 0
#define INCLUDE_vTaskSuspend 1
#define INCLUDE_vTaskDelayUntil 1
#define INCLUDE_vTaskDelay 1
#define INCLUDE_uxTaskGetStackHighWaterMark 1
/* The priority at which the tick interrupt runs. This should probably bekept at 1. */
#define configKERNEL_INTERRUPT_PRIORITY 0x01
/* The maximum interrupt priority from which FreeRTOS.org API functions canbe called. Only API functions that end in ...FromISR() can be used withininterrupts. */
#define configMAX_SYSCALL_INTERRUPT_PRIORITY 0x03
The serial port is initialized in thi way: (RB14 is the direction for RS-485, ulBaudRate is 57600 Baud)
PORTSetPinsDigitalOut( IOPORT_B, BIT_14);
PORTClearBits( IOPORT_B, BIT_14);
// Resto configurazione
UARTConfigure(UART2, UART_ENABLE_PINS_TX_RX_ONLY );
UARTSetFifoMode(UART2, UART_INTERRUPT_ON_TX_DONE | UART_INTERRUPT_ON_RX_NOT_EMPTY);
UARTSetLineControl(UART2, mode);
UARTSetDataRate(UART2, 25000000ul, ulBaudRate);
UARTEnable(UART2, UART_ENABLE_FLAGS(UART_PERIPHERAL | UART_RX | UART_TX));
INTClearFlag(INT_SOURCE_UART_RX(UART2));
INTClearFlag(INT_SOURCE_UART_TX(UART2));
INTSetVectorPriority(INT_VECTOR_UART(UART2), INT_PRIORITY_LEVEL_5);
INTSetVectorSubPriority(INT_VECTOR_UART(UART2), INT_SUB_PRIORITY_LEVEL_0);
// Configure UART2 RX Interrupt
INTEnable(INT_SOURCE_UART_RX(UART2), INT_ENABLED);
The UART interrupt: (I try with the wrapper with assembly code and this version, direct in the ISR )
//void __attribute__( (interrupt(ipl5), vector(_UART_2_VECTOR))) vMBInterruptWrapper( void );
void __ISR(_UART_2_VECTOR, ipl5) vMBInterruptHandler(void)[/code]
I debug the program and 2 or 3 times per second I send a packet ModBus with a dedicated C#-program.
My code responde to the packet until excpetion appears
What it happen is that, after some time, the code give exception with this value:
Expeption #7 (load/store exception)
EPC: 0x9D009528
At that program counter the code assemply is this:
175: pxItemToRemove->pxPrevious->pxNext = pxItemToRemove->pxNext;
9D009504 8FC20010 LW V0, 16(S8)
9D009508 8C420008 LW V0, 8(V0)
9D00950C 8FC30010 LW V1, 16(S8)
9D009510 8C630004 LW V1, 4(V1)
9D009514 AC430004 SW V1, 4(V0)
176:
177: /* The list item knows which list it is in. Obtain the list from the list178: item. */
179: pxList = ( xList * ) pxItemToRemove->pvContainer;
9D009518 8FC20010 LW V0, 16(S8)
9D00951C 8C420010 LW V0, 16(V0)
9D009520 AFC20000 SW V0, 0(S8)
180:
181: /* Make sure the index is left pointing to a valid item. */
182: if( pxList->pxIndex == pxItemToRemove )
9D009524 8FC20000 LW V0, 0(S8)
9D009528 8C430004 LW V1, 4(V0)
9D00952C 8FC20010 LW V0, 16(S8)
9D009530 14620005 BNE V1, V0, 0x9D009548
9D009534 00000000 NOP183: {
184: pxList->pxIndex = pxItemToRemove->pxPrevious;
9D009538 8FC20010 LW V0, 16(S8)
9D00953C 8C430008 LW V1, 8(V0)
9D009540 8FC20000 LW V0, 0(S8)
9D009544 AC430004 SW V1, 4(V0)
185: }
that is the C code corrisponding to the FreeRTOS internal code:
void vListRemove( xListItem *pxItemToRemove ){xList * pxList;
pxItemToRemove->pxNext->pxPrevious = pxItemToRemove->pxPrevious;
pxItemToRemove->pxPrevious->pxNext = pxItemToRemove->pxNext; /* The list item knows which list it is in. Obtain the list from the list item. */
pxList = ( xList * ) pxItemToRemove->pvContainer;
/* Make sure the index is left pointing to a valid item. */
if( pxList->pxIndex == pxItemToRemove ) { pxList->pxIndex = pxItemToRemove->pxPrevious; }
pxItemToRemove->pvContainer = NULL; ( pxList->uxNumberOfItems )--;
}
the timer for timeout modbus (timeout for PKT recived) is this:
void _ISR(TIMER2VECTOR, ipl5) Timer2Handler(void){
// every 100us (= 0.1msec)
if (TickTimeoutMBmsecX10>0){
TickTimeoutMBmsecX10--;
if(TickTimeoutMB_msecX10==0)
{vMBTimerInterruptHandler();}
}
timer defined here: (TIMER2PERIOD= 2500)
OpenTimer2(T2ON , TIMER2PERIOD);
INTEnable(INTT2, INTENABLED);
INTSetVectorPriority(INTTIMER2VECTOR, INTPRIORITYLEVEL5);
INTSetVectorSubPriority(INTTIMER2VECTOR, INTSUBPRIORITYLEVEL0);
and routine called during timer 2 ISR on timeout:
BOOL
xMBRTUTimerT35Expired( void )
{
BOOL xNeedPoll = FALSE;
portBASE_TYPE xHigherPriorityTaskWoken = pdTRUE;
switch ( eRcvState )
{
-……..
}
xSemaphoreGiveFromISR(xBinaryMBManage,&xHigherPriorityTaskWoken);
return xNeedPoll;
}
Conclusion:
I debug the program and 2 or 3 times per second I send a packet ModBus .
My code responde to the packet until excpetion appears
Expeption #7 (load/store exception)
EPC: 0x9D009528
Try:
I try to comment the task creation of the ADC process but there are no change on the behavior of the code.
If I try to modified the time of semaphoreGive to MB process the exception do not change but occurs before or after. If I use 1msec in few then one minute the exception appears If I use 95msec very much time. (I left uP all week end operate and yestorday eavening the exception occurs).
I can't expand time to infinity... There is something wrong that I can't find!
Help that I need! :
Some one have advice... please tell me! I do not know what else do....
If you want some other part of code or information please tell me and I will answer in a few than a hour!
Many thanks!
Massimiliano
I'm not following all this, but some questions:
First - you have configMAXSYSCALLINTERRUPT_PRIORITY set to 3, but then set the priority of tasks that use system calls to 5. This will definitely cause you a problem. Please read the documentation page for the PIC32 port (link further down in this post).
In your calls to xTaskCreate() you are setting the stack size to:
"(configMINIMALSTACKSIZE)3"
I'm not sure what that will do. configMINIMALSTACKSIZE is defined as ( 380 ), so the preprocessor will example the stack size parameter to "( ( 380 ) )3". Is that even valid C code?
Currently you have configCHECKFORSTACKOVERFLOW set to 0. Why is that? Given the strange code used to allocate the stack size your problem could be a stack overflow. What happens when you set configCHECKFORSTACKOVERFLOW to 2 and define the stack overflow hook function?
I would recommend defining configASSERT(), it might highlight a problem for you. http://www.freertos.org/a00110.html#configASSERT
The documentation page for the PIC32 tells you how to write interrupt service routines. It does not look like you are following the guidelines. See the "Interrupt Service Routines" section: http://www.freertos.org/portPIC32MIPS_MK4.html
Regards.
Before all: Thanks for your answer!
About your first answer (priority level):
You are right: but the max priority aviable of the task isn't defined by: "configMAXPRIORITIES" ? I defined configMAXPRIORITIES=5
I do not know that configMAXPRIORITIES must be < than configMAXSYSCALLINTERRUPTPRIORITY ... but if I'm wrong and this must be true I will change immediately those two define.
About your second answer ( (configMINIMALSTACKSIZE)3 )
You are right: I write (configMINIMALSTACKSIZE)3 but ,I do not understand why, the forum delete my ""!!! If I try to modify the post the "" is present but when I save the post the "" disappears!
About your third answer (stack overflow)
i use a FreeRTOS version where there isn't a stack overflow activated. Now I will active them and implements a stack overflow hook (where I can take this function? Meanwhile I search on the Microchip forum)
Now I read the two link, about assert and about ISR.
Many thanks