]> git.sur5r.net Git - freertos/blobdiff - FreeRTOS/Source/portable/GCC/ARM_CM0/port.c
Update version number in preparation for maintenance release.
[freertos] / FreeRTOS / Source / portable / GCC / ARM_CM0 / port.c
index 6966c848efaf9d188fb29d6ad034676b2864299b..b70a49af20a58a2eccc145cb6f4b92c5ca034284 100644 (file)
@@ -1,59 +1,64 @@
 /*\r
-    FreeRTOS V7.5.2 - Copyright (C) 2013 Real Time Engineers Ltd.\r
+    FreeRTOS V9.0.1 - Copyright (C) 2017 Real Time Engineers Ltd.\r
+    All rights reserved\r
 \r
     VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.\r
 \r
-    ***************************************************************************\r
-     *                                                                       *\r
-     *    FreeRTOS provides completely free yet professionally developed,    *\r
-     *    robust, strictly quality controlled, supported, and cross          *\r
-     *    platform software that has become a de facto standard.             *\r
-     *                                                                       *\r
-     *    Help yourself get started quickly and support the FreeRTOS         *\r
-     *    project by purchasing a FreeRTOS tutorial book, reference          *\r
-     *    manual, or both from: http://www.FreeRTOS.org/Documentation        *\r
-     *                                                                       *\r
-     *    Thank you!                                                         *\r
-     *                                                                       *\r
-    ***************************************************************************\r
-\r
     This file is part of the FreeRTOS distribution.\r
 \r
     FreeRTOS is free software; you can redistribute it and/or modify it under\r
     the terms of the GNU General Public License (version 2) as published by the\r
-    Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.\r
+    Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception.\r
 \r
-    >>! NOTE: The modification to the GPL is included to allow you to distribute\r
-    >>! a combined work that includes FreeRTOS without being obliged to provide\r
-    >>! the source code for proprietary components outside of the FreeRTOS\r
-    >>! kernel.\r
+    ***************************************************************************\r
+    >>!   NOTE: The modification to the GPL is included to allow you to     !<<\r
+    >>!   distribute a combined work that includes FreeRTOS without being   !<<\r
+    >>!   obliged to provide the source code for proprietary components     !<<\r
+    >>!   outside of the FreeRTOS kernel.                                   !<<\r
+    ***************************************************************************\r
 \r
     FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY\r
     WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS\r
-    FOR A PARTICULAR PURPOSE.  Full license text is available from the following\r
+    FOR A PARTICULAR PURPOSE.  Full license text is available on the following\r
     link: http://www.freertos.org/a00114.html\r
 \r
-    1 tab == 4 spaces!\r
-\r
     ***************************************************************************\r
      *                                                                       *\r
-     *    Having a problem?  Start by reading the FAQ "My application does   *\r
-     *    not run, what could be wrong?"                                     *\r
+     *    FreeRTOS provides completely free yet professionally developed,    *\r
+     *    robust, strictly quality controlled, supported, and cross          *\r
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+     *    is the industry's de facto standard.                               *\r
      *                                                                       *\r
-     *    http://www.FreeRTOS.org/FAQHelp.html                               *\r
+     *    Help yourself get started quickly while simultaneously helping     *\r
+     *    to support the FreeRTOS project by purchasing a FreeRTOS           *\r
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+     *    http://www.FreeRTOS.org/Documentation                              *\r
      *                                                                       *\r
     ***************************************************************************\r
 \r
-    http://www.FreeRTOS.org - Documentation, books, training, latest versions,\r
-    license and Real Time Engineers Ltd. contact details.\r
+    http://www.FreeRTOS.org/FAQHelp.html - Having a problem?  Start by reading\r
+    the FAQ page "My application does not run, what could be wrong?".  Have you\r
+    defined configASSERT()?\r
+\r
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+    embedded software for free we request you assist our global community by\r
+    participating in the support forum.\r
+\r
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     including FreeRTOS+Trace - an indispensable productivity tool, a DOS\r
     compatible FAT file system, and our tiny thread aware UDP/IP stack.\r
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-    Integrity Systems to sell under the OpenRTOS brand.  Low cost OpenRTOS\r
-    licenses offer ticketed support, indemnification and middleware.\r
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+    Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.\r
+\r
+    http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High\r
+    Integrity Systems ltd. to sell under the OpenRTOS brand.  Low cost OpenRTOS\r
+    licenses offer ticketed support, indemnification and commercial middleware.\r
 \r
     http://www.SafeRTOS.com - High Integrity Systems also provide a safety\r
     engineered and independently SIL3 certified version for use in safety and\r
 #include "task.h"\r
 \r
 /* Constants required to manipulate the NVIC. */\r
-#define portNVIC_SYSTICK_CTRL          ( ( volatile unsigned long *) 0xe000e010 )\r
-#define portNVIC_SYSTICK_LOAD          ( ( volatile unsigned long *) 0xe000e014 )\r
-#define portNVIC_INT_CTRL                      ( ( volatile unsigned long *) 0xe000ed04 )\r
-#define portNVIC_SYSPRI2                       ( ( volatile unsigned long *) 0xe000ed20 )\r
+#define portNVIC_SYSTICK_CTRL                  ( ( volatile uint32_t * ) 0xe000e010 )\r
+#define portNVIC_SYSTICK_LOAD                  ( ( volatile uint32_t * ) 0xe000e014 )\r
+#define portNVIC_SYSTICK_CURRENT_VALUE ( ( volatile uint32_t * ) 0xe000e018 )\r
+#define portNVIC_INT_CTRL                      ( ( volatile uint32_t *) 0xe000ed04 )\r
+#define portNVIC_SYSPRI2                       ( ( volatile uint32_t *) 0xe000ed20 )\r
 #define portNVIC_SYSTICK_CLK           0x00000004\r
 #define portNVIC_SYSTICK_INT           0x00000002\r
 #define portNVIC_SYSTICK_ENABLE                0x00000001\r
 /* Constants required to set up the initial stack. */\r
 #define portINITIAL_XPSR                       ( 0x01000000 )\r
 \r
+/* Let the user override the pre-loading of the initial LR with the address of\r
+prvTaskExitError() in case it messes up unwinding of the stack in the\r
+debugger. */\r
+#ifdef configTASK_RETURN_ADDRESS\r
+       #define portTASK_RETURN_ADDRESS configTASK_RETURN_ADDRESS\r
+#else\r
+       #define portTASK_RETURN_ADDRESS prvTaskExitError\r
+#endif\r
+\r
 /* Each task maintains its own interrupt status in the critical nesting\r
 variable. */\r
-static unsigned portBASE_TYPE uxCriticalNesting = 0xaaaaaaaa;\r
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;\r
 \r
 /*\r
  * Setup the timer to generate the tick interrupts.\r
@@ -100,59 +115,59 @@ static void prvSetupTimerInterrupt( void );
  */\r
 void xPortPendSVHandler( void ) __attribute__ (( naked ));\r
 void xPortSysTickHandler( void );\r
-void vPortSVCHandler( void ) __attribute__ (( naked ));\r
+void vPortSVCHandler( void );\r
 \r
 /*\r
  * Start first task is a separate function so it can be tested in isolation.\r
  */\r
 static void vPortStartFirstTask( void ) __attribute__ (( naked ));\r
 \r
+/*\r
+ * Used to catch tasks that attempt to return from their implementing function.\r
+ */\r
+static void prvTaskExitError( void );\r
+\r
 /*-----------------------------------------------------------*/\r
 \r
 /*\r
  * See header file for description.\r
  */\r
-portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )\r
+StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )\r
 {\r
        /* Simulate the stack frame as it would be created by a context switch\r
        interrupt. */\r
        pxTopOfStack--; /* Offset added to account for the way the MCU uses the stack on entry/exit of interrupts. */\r
        *pxTopOfStack = portINITIAL_XPSR;       /* xPSR */\r
        pxTopOfStack--;\r
-       *pxTopOfStack = ( portSTACK_TYPE ) pxCode;      /* PC */\r
-       pxTopOfStack -= 6;      /* LR, R12, R3..R1 */\r
-       *pxTopOfStack = ( portSTACK_TYPE ) pvParameters;        /* R0 */\r
+       *pxTopOfStack = ( StackType_t ) pxCode; /* PC */\r
+       pxTopOfStack--;\r
+       *pxTopOfStack = ( StackType_t ) portTASK_RETURN_ADDRESS;        /* LR */\r
+       pxTopOfStack -= 5;      /* R12, R3, R2 and R1. */\r
+       *pxTopOfStack = ( StackType_t ) pvParameters;   /* R0 */\r
        pxTopOfStack -= 8; /* R11..R4. */\r
 \r
        return pxTopOfStack;\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
+static void prvTaskExitError( void )\r
+{\r
+       /* A function that implements a task must not exit or attempt to return to\r
+       its caller as there is nothing to return to.  If a task wants to exit it\r
+       should instead call vTaskDelete( NULL ).\r
+\r
+       Artificially force an assert() to be triggered if configASSERT() is\r
+       defined, then stop here so application writers can catch the error. */\r
+       configASSERT( uxCriticalNesting == ~0UL );\r
+       portDISABLE_INTERRUPTS();\r
+       for( ;; );\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
 void vPortSVCHandler( void )\r
 {\r
-       __asm volatile (\r
-                                       "       ldr     r3, pxCurrentTCBConst2          \n" /* Restore the context. */\r
-                                       "       ldr r1, [r3]                                    \n" /* Use pxCurrentTCBConst to get the pxCurrentTCB address. */\r
-                                       "       ldr r0, [r1]                                    \n" /* The first item in pxCurrentTCB is the task top of stack. */\r
-                                       "       add r0, r0, #16                                 \n" /* Move to the high registers. */\r
-                                       "       ldmia r0!, {r4-r7}                              \n" /* Pop the high registers. */\r
-                                       "       mov r8, r4                                              \n"\r
-                                       "       mov r9, r5                                              \n"\r
-                                       "       mov r10, r6                                             \n"\r
-                                       "       mov r11, r7                                             \n"\r
-                                       "                                                                       \n"\r
-                                       "       msr psp, r0                                             \n" /* Remember the new top of stack for the task. */\r
-                                       "                                                                       \n"\r
-                                       "       sub r0, r0, #32                                 \n" /* Go back for the low registers that are not automatically restored. */\r
-                                       "       ldmia r0!, {r4-r7}              \n" /* Pop low registers.  */\r
-                                       "       mov r1, r14                                             \n" /* OR R14 with 0x0d. */\r
-                                       "       movs r0, #0x0d                                  \n"\r
-                                       "       orr r1, r0                                              \n"\r
-                                       "       bx r1                                                   \n"\r
-                                       "                                                                       \n"\r
-                                       "       .align 2                                                \n"\r
-                                       "pxCurrentTCBConst2: .word pxCurrentTCB \n"\r
-                               );\r
+       /* This function is no longer used, but retained for backward\r
+       compatibility. */\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
@@ -162,9 +177,23 @@ void vPortStartFirstTask( void )
        table offset register that can be used to locate the initial stack value.\r
        Not all M0 parts have the application vector table at address 0. */\r
        __asm volatile(\r
-                                       " cpsie i                       \n" /* Globally enable interrupts. */\r
-                                       " svc 0                         \n" /* System call to start first task. */\r
-                                       " nop                           \n"\r
+       "       ldr     r2, pxCurrentTCBConst2  \n" /* Obtain location of pxCurrentTCB. */\r
+       "       ldr r3, [r2]                            \n"\r
+       "       ldr r0, [r3]                            \n" /* The first item in pxCurrentTCB is the task top of stack. */\r
+       "       add r0, #32                                     \n" /* Discard everything up to r0. */\r
+       "       msr psp, r0                                     \n" /* This is now the new top of stack to use in the task. */\r
+       "       movs r0, #2                                     \n" /* Switch to the psp stack. */\r
+       "       msr CONTROL, r0                         \n"\r
+       "       isb                                                     \n"\r
+       "       pop {r0-r5}                                     \n" /* Pop the registers that are saved automatically. */\r
+       "       mov lr, r5                                      \n" /* lr is now in r5. */\r
+       "       pop {r3}                                        \n" /* Return address is now in r3. */\r
+       "       pop {r2}                                        \n" /* Pop and discard XPSR. */\r
+       "       cpsie i                                         \n" /* The first task has its context and interrupts can be enabled. */\r
+       "       bx r3                                           \n" /* Finally, jump to the user defined task code. */\r
+       "                                                               \n"\r
+       "       .align 4                                        \n"\r
+       "pxCurrentTCBConst2: .word pxCurrentTCB   "\r
                                  );\r
 }\r
 /*-----------------------------------------------------------*/\r
@@ -172,7 +201,7 @@ void vPortStartFirstTask( void )
 /*\r
  * See header file for description.\r
  */\r
-portBASE_TYPE xPortStartScheduler( void )\r
+BaseType_t xPortStartScheduler( void )\r
 {\r
        /* Make PendSV, CallSV and SysTick the same priroity as the kernel. */\r
        *(portNVIC_SYSPRI2) |= portNVIC_PENDSV_PRI;\r
@@ -188,6 +217,12 @@ portBASE_TYPE xPortStartScheduler( void )
        /* Start the first task. */\r
        vPortStartFirstTask();\r
 \r
+       /* Should never get here as the tasks will now be executing!  Call the task\r
+       exit error function to prevent compiler warnings about a static function\r
+       not being called in the case that the application writer overrides this\r
+       functionality by defining configTASK_RETURN_ADDRESS. */\r
+       prvTaskExitError();\r
+\r
        /* Should not get here! */\r
        return 0;\r
 }\r
@@ -195,8 +230,9 @@ portBASE_TYPE xPortStartScheduler( void )
 \r
 void vPortEndScheduler( void )\r
 {\r
-  /* It is unlikely that the CM0 port will require this function as there\r
-    is nothing to return to.  */\r
+       /* Not implemented in ports where there is nothing to return to.\r
+       Artificially force an assert. */\r
+       configASSERT( uxCriticalNesting == 1000UL );\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
@@ -223,6 +259,7 @@ void vPortEnterCritical( void )
 \r
 void vPortExitCritical( void )\r
 {\r
+       configASSERT( uxCriticalNesting );\r
     uxCriticalNesting--;\r
     if( uxCriticalNesting == 0 )\r
     {\r
@@ -231,7 +268,7 @@ void vPortExitCritical( void )
 }\r
 /*-----------------------------------------------------------*/\r
 \r
-unsigned long ulSetInterruptMaskFromISR( void )\r
+uint32_t ulSetInterruptMaskFromISR( void )\r
 {\r
        __asm volatile(\r
                                        " mrs r0, PRIMASK       \n"\r
@@ -244,12 +281,15 @@ unsigned long ulSetInterruptMaskFromISR( void )
 }\r
 /*-----------------------------------------------------------*/\r
 \r
-void vClearInterruptMaskFromISR( unsigned long ulMask )\r
+void vClearInterruptMaskFromISR( uint32_t ulMask )\r
 {\r
        __asm volatile(\r
                                        " msr PRIMASK, r0       \n"\r
                                        " bx lr                           "\r
                                  );\r
+\r
+       /* Just to avoid compiler warning. */\r
+       ( void ) ulMask;\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
@@ -271,7 +311,7 @@ void xPortPendSVHandler( void )
        "       mov r5, r9                                                      \n"\r
        "       mov r6, r10                                                     \n"\r
        "       mov r7, r11                                                     \n"\r
-       "       stmia r0!, {r4-r7}                      \n"\r
+       "       stmia r0!, {r4-r7}                                      \n"\r
        "                                                                               \n"\r
        "       push {r3, r14}                                          \n"\r
        "       cpsid i                                                         \n"\r
@@ -291,11 +331,11 @@ void xPortPendSVHandler( void )
        "       msr psp, r0                                                     \n" /* Remember the new top of stack for the task. */\r
        "                                                                               \n"\r
        "       sub r0, r0, #32                                         \n" /* Go back for the low registers that are not automatically restored. */\r
-       "       ldmia r0!, {r4-r7}                      \n" /* Pop low registers.  */\r
+       "       ldmia r0!, {r4-r7}                                      \n" /* Pop low registers.  */\r
        "                                                                               \n"\r
        "       bx r3                                                           \n"\r
        "                                                                               \n"\r
-       "       .align 2                                                        \n"\r
+       "       .align 4                                                        \n"\r
        "pxCurrentTCBConst: .word pxCurrentTCB    "\r
        );\r
 }\r
@@ -303,7 +343,7 @@ void xPortPendSVHandler( void )
 \r
 void xPortSysTickHandler( void )\r
 {\r
-unsigned long ulPreviousMask;\r
+uint32_t ulPreviousMask;\r
 \r
        ulPreviousMask = portSET_INTERRUPT_MASK_FROM_ISR();\r
        {\r
@@ -324,6 +364,10 @@ unsigned long ulPreviousMask;
  */\r
 void prvSetupTimerInterrupt( void )\r
 {\r
+       /* Stop and reset the SysTick. */\r
+       *(portNVIC_SYSTICK_CTRL) = 0UL;\r
+       *(portNVIC_SYSTICK_CURRENT_VALUE) = 0UL;\r
+\r
        /* Configure SysTick to interrupt at the requested rate. */\r
        *(portNVIC_SYSTICK_LOAD) = ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;\r
        *(portNVIC_SYSTICK_CTRL) = portNVIC_SYSTICK_CLK | portNVIC_SYSTICK_INT | portNVIC_SYSTICK_ENABLE;\r