***************************************************************************\r
*/\r
\r
-/*\r
- Changes between V4.0.0 and V4.0.1\r
-\r
- + Reduced the code used to setup the initial stack frame.\r
- + The kernel no longer has to install or handle the fault interrupt.\r
-*/\r
-\r
/*-----------------------------------------------------------\r
* Implementation of functions defined in portable.h for the ARM CM3 port.\r
*----------------------------------------------------------*/\r
#include "FreeRTOS.h"\r
#include "task.h"\r
\r
+#ifndef configKERNEL_INTERRUPT_PRIORITY\r
+ #define configKERNEL_INTERRUPT_PRIORITY 255\r
+#endif\r
+\r
/* Constants required to manipulate the NVIC. */\r
#define portNVIC_SYSTICK_CTRL ( ( volatile unsigned portLONG *) 0xe000e010 )\r
#define portNVIC_SYSTICK_LOAD ( ( volatile unsigned portLONG *) 0xe000e014 )\r
#define portNVIC_INT_CTRL ( ( volatile unsigned portLONG *) 0xe000ed04 )\r
#define portNVIC_SYSPRI2 ( ( volatile unsigned portLONG *) 0xe000ed20 )\r
-#define portNVIC_SYSPRI1 ( ( volatile unsigned portLONG *) 0xe000ed1c )\r
-#define portNVIC_HARD_FAULT_STATUS 0xe000ed2c\r
-#define portNVIC_FORCED_FAULT_BIT 0x40000000\r
#define portNVIC_SYSTICK_CLK 0x00000004\r
#define portNVIC_SYSTICK_INT 0x00000002\r
#define portNVIC_SYSTICK_ENABLE 0x00000001\r
#define portNVIC_PENDSVSET 0x10000000\r
-#define portNVIC_PENDSV_PRI 0x00ff0000\r
-#define portNVIC_SVCALL_PRI 0xff000000\r
-#define portNVIC_SYSTICK_PRI 0xff000000\r
+#define portNVIC_PENDSV_PRI ( ( ( unsigned portLONG ) configKERNEL_INTERRUPT_PRIORITY ) << 16 )\r
+#define portNVIC_SYSTICK_PRI ( ( ( unsigned portLONG ) configKERNEL_INTERRUPT_PRIORITY ) << 24 )\r
\r
/* Constants required to set up the initial stack. */\r
#define portINITIAL_XPSR ( 0x01000000 )\r
variable. */\r
unsigned portBASE_TYPE uxCriticalNesting = 0xaaaaaaaa;\r
\r
-/* Constant hardware definitions to assist asm code. */\r
-const unsigned long ulHardFaultStatus = portNVIC_HARD_FAULT_STATUS;\r
-const unsigned long ulNVICIntCtrl = ( unsigned long ) 0xe000ed04;\r
-const unsigned long ulForceFaultBit = portNVIC_FORCED_FAULT_BIT;\r
-const unsigned long ulPendSVBit = portNVIC_PENDSVSET;\r
-\r
/* \r
* Setup the timer to generate the tick interrupts.\r
*/\r
static void prvSetupTimerInterrupt( void );\r
\r
/*\r
- * Set the MSP/PSP to a known value.\r
+ * Exception handlers.\r
*/\r
-void prvSetMSP( unsigned long ulValue );\r
-void prvSetPSP( unsigned long ulValue );\r
+void xPortPendSVHandler( void );\r
+void xPortSysTickHandler( void );\r
+void vPortSVCHandler( void );\r
+\r
+/*\r
+ * Start first task is a separate function so it can be tested in isolation.\r
+ */\r
+void vPortStartFirstTask( unsigned long ulValue );\r
\r
/*-----------------------------------------------------------*/\r
\r
pxTopOfStack--;\r
*pxTopOfStack = ( portSTACK_TYPE ) pxCode; /* PC */\r
pxTopOfStack--;\r
- *pxTopOfStack = 0xfffffffd; /* LR */\r
+ *pxTopOfStack = 0; /* LR */\r
pxTopOfStack -= 5; /* R12, R3, R2 and R1. */\r
*pxTopOfStack = ( portSTACK_TYPE ) pvParameters; /* R0 */\r
pxTopOfStack -= 9; /* R11, R10, R9, R8, R7, R6, R5 and R4. */\r
}\r
/*-----------------------------------------------------------*/\r
\r
-__asm void prvSetPSP( unsigned long ulValue )\r
+__asm void vPortSVCHandler( void )\r
{\r
PRESERVE8\r
- msr psp, r0\r
- bx lr;\r
+\r
+ ldr r3, =pxCurrentTCB /* Restore the context. */\r
+ ldr r1, [r3] /* Use pxCurrentTCBConst to get the pxCurrentTCB address. */\r
+ ldr r0, [r1] /* The first item in pxCurrentTCB is the task top of stack. */\r
+ ldmia r0!, {r1, r4-r11} /* Pop the registers that are not automatically saved on exception entry and the critical nesting count. */\r
+ ldr r2, =uxCriticalNesting /* Restore the critical nesting count used by the task. */\r
+ str r1, [r2] \r
+ msr psp, r0 /* Restore the task stack pointer. */\r
+ orr r14, #0xd \r
+ bx r14 \r
}\r
/*-----------------------------------------------------------*/\r
\r
-__asm void prvSetMSP( unsigned long ulValue )\r
+__asm void vPortStartFirstTask( unsigned long ulValue )\r
{\r
PRESERVE8\r
- msr msp, r0\r
- bx lr;\r
+\r
+ msr msp, r0 /* Set the msp back to the start of the stack. */\r
+ svc 0 /* System call to start first task. */\r
}\r
/*-----------------------------------------------------------*/\r
\r
*/\r
portBASE_TYPE xPortStartScheduler( void )\r
{\r
- /* Start the timer that generates the tick ISR. Interrupts are disabled\r
- here already. */\r
- prvSetupTimerInterrupt();\r
-\r
- /* Make PendSV, CallSV and SysTick the lowest priority interrupts. */\r
+ /* Make PendSV, CallSV and SysTick the same priroity as the kernel. */\r
*(portNVIC_SYSPRI2) |= portNVIC_PENDSV_PRI;\r
*(portNVIC_SYSPRI2) |= portNVIC_SYSTICK_PRI;\r
- *(portNVIC_SYSPRI1) |= portNVIC_SVCALL_PRI;\r
\r
+ /* Start the timer that generates the tick ISR. Interrupts are disabled\r
+ here already. */\r
+ prvSetupTimerInterrupt();\r
+ \r
/* Start the first task. */\r
- prvSetPSP( 0 );\r
- prvSetMSP( *((unsigned portLONG *) 0 ) );\r
- *(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;\r
-\r
- /* Enable interrupts */\r
- portENABLE_INTERRUPTS();\r
+ vPortStartFirstTask( *((unsigned portLONG *) 0 ) );\r
\r
/* Should not get here! */\r
return 0;\r
void vPortYieldFromISR( void )\r
{\r
/* Set a PendSV to request a context switch. */\r
- *(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET; \r
- portENABLE_INTERRUPTS();\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-__asm void vPortDisableInterrupts( void )\r
-{\r
- PRESERVE8\r
- cpsid i;\r
- bx lr;\r
-}\r
-/*-----------------------------------------------------------*/\r
+ *(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;\r
\r
-__asm void vPortEnableInterrupts( void )\r
-{\r
- PRESERVE8\r
- cpsie i;\r
- bx lr;\r
+ /* This function is also called in response to a Yield(), so we want\r
+ the yield to occur immediately. */\r
+ portENABLE_INTERRUPTS();\r
}\r
/*-----------------------------------------------------------*/\r
\r
void vPortEnterCritical( void )\r
{\r
- vPortDisableInterrupts();\r
+ portDISABLE_INTERRUPTS();\r
uxCriticalNesting++;\r
}\r
/*-----------------------------------------------------------*/\r
uxCriticalNesting--;\r
if( uxCriticalNesting == 0 )\r
{\r
- vPortEnableInterrupts();\r
+ portENABLE_INTERRUPTS();\r
}\r
}\r
/*-----------------------------------------------------------*/\r
\r
PRESERVE8\r
\r
- /* Start first task if the stack has not yet been setup. */\r
- mrs r0, psp \r
- cbz r0, no_save \r
+ mrs r0, psp \r
\r
- /* Save the context into the TCB. */\r
- stmdb r0!, {r4-r11} \r
- sub r0, r0, #0x04 \r
- ldr r1, =uxCriticalNesting\r
- ldr r2, =pxCurrentTCB \r
+ ldr r3, =pxCurrentTCB /* Get the location of the current TCB. */\r
+ ldr r2, [r3] \r
+\r
+ ldr r1, =uxCriticalNesting /* Save the remaining registers and the critical nesting count onto the task stack. */\r
ldr r1, [r1] \r
- ldr r2, [r2] \r
- str r1, [r0] \r
- str r0, [r2] \r
+ stmdb r0!, {r1,r4-r11} \r
+ str r0, [r2] /* Save the new top of stack into the first member of the TCB. */\r
\r
-no_save;\r
- \r
- /* Find the task to execute. */\r
- push {r14}\r
- cpsid i\r
- bl vTaskSwitchContext\r
- cpsie i\r
- pop {r14} \r
-\r
- /* Restore the context. */\r
- ldr r1, =pxCurrentTCB\r
- ldr r1, [r1];\r
- ldr r0, [r1];\r
- ldmia r0!, {r1, r4-r11}\r
+ stmdb sp!, {r3, r14} \r
+ bl vTaskSwitchContext \r
+ ldmia sp!, {r3, r14} \r
+\r
+ ldr r1, [r3] \r
ldr r2, =uxCriticalNesting\r
- str r1, [r2]\r
- ldr r2, [r2]\r
- msr psp, r0\r
- orr r14, #0xd\r
+ ldr r0, [r1] /* The first item in pxCurrentTCB is the task top of stack. */\r
+ ldmia r0!, {r1, r4-r11} /* Pop the registers and the critical nesting count. */\r
+ str r1, [r2] /* Save the new critical nesting value into ulCriticalNesting. */ \r
+ msr psp, r0 \r
+ orr r14, #0xd \r
\r
- /* Exit with interrupts in the state required by the task. */\r
- cbnz r2, sv_disable_interrupts\r
- \r
+ cbnz r1, sv_disable_interrupts /* If the nesting count is greater than 0 we need to exit with interrupts masked. */\r
bx r14\r
\r
-sv_disable_interrupts;\r
- cpsid i\r
- bx r14\r
+sv_disable_interrupts\r
+ mov r1, #configKERNEL_INTERRUPT_PRIORITY\r
+ msr basepri, r1 \r
+ bx r14 \r
}\r
/*-----------------------------------------------------------*/\r
\r
-__asm void xPortSysTickHandler( void )\r
+void xPortSysTickHandler( void )\r
{\r
- extern vTaskIncrementTick\r
- PRESERVE8\r
-\r
- /* Call the scheduler tick function. */\r
- push {r14}\r
- cpsid i\r
- bl vTaskIncrementTick\r
- cpsie i\r
- pop {r14} \r
-\r
+ vTaskIncrementTick();\r
+ \r
/* If using preemption, also force a context switch. */\r
#if configUSE_PREEMPTION == 1\r
- extern vPortYieldFromISR\r
- push {r14}\r
- bl vPortYieldFromISR\r
- pop {r14}\r
+ *(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET; \r
#endif\r
-\r
- /* Exit with interrupts in the correct state. */\r
- ldr r2, =uxCriticalNesting\r
- ldr r2, [r2]\r
- cbnz r2, tick_disable_interrupts\r
-\r
- bx r14\r
-\r
-tick_disable_interrupts;\r
- cpsid i\r
- bx r14\r
}\r
/*-----------------------------------------------------------*/\r
\r
*(portNVIC_SYSTICK_LOAD) = configCPU_CLOCK_HZ / configTICK_RATE_HZ;\r
*(portNVIC_SYSTICK_CTRL) = portNVIC_SYSTICK_CLK | portNVIC_SYSTICK_INT | portNVIC_SYSTICK_ENABLE;\r
}\r
+/*-----------------------------------------------------------*/\r
\r
+__asm void vPortSetInterruptMask( void )\r
+{\r
+ PRESERVE8\r
\r
+ push { r0 }\r
+ mov r0, #configKERNEL_INTERRUPT_PRIORITY\r
+ msr basepri, r0\r
+ pop { r0 }\r
+}\r
+\r
+/*-----------------------------------------------------------*/\r
+\r
+__asm void vPortClearInterruptMask( void )\r
+{\r
+ PRESERVE8\r
+\r
+ push { r0 }\r
+ mov r0, #0\r
+ msr basepri, r0\r
+ pop { r0 }\r
+}\r
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