]> git.sur5r.net Git - freertos/blobdiff - Source/portable/GCC/ARM_CM3/port.c
Add an cpsie i before the SVC call that starts the scheduler. This is just in case...
[freertos] / Source / portable / GCC / ARM_CM3 / port.c
index 8c5ab7fcedcf3b128655b9901555ddeb79db9091..85d28c6ecd0029aab1574ebe27016d7634f00b45 100644 (file)
@@ -1,50 +1,54 @@
 /*\r
-       FreeRTOS.org V5.0.2 - Copyright (C) 2003-2008 Richard Barry.\r
+    FreeRTOS V6.1.0 - Copyright (C) 2010 Real Time Engineers Ltd.\r
 \r
-       This file is part of the FreeRTOS.org distribution.\r
-\r
-       FreeRTOS.org is free software; you can redistribute it and/or modify\r
-       it under the terms of the GNU General Public License as published by\r
-       the Free Software Foundation; either version 2 of the License, or\r
-       (at your option) any later version.\r
-\r
-       FreeRTOS.org is distributed in the hope that it will be useful,\r
-       but WITHOUT ANY WARRANTY; without even the implied warranty of\r
-       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
-       GNU General Public License for more details.\r
-\r
-       You should have received a copy of the GNU General Public License\r
-       along with FreeRTOS.org; if not, write to the Free Software\r
-       Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA\r
-\r
-       A special exception to the GPL can be applied should you wish to distribute\r
-       a combined work that includes FreeRTOS.org, without being obliged to provide\r
-       the source code for any proprietary components.  See the licensing section \r
-       of http://www.FreeRTOS.org for full details of how and when the exception\r
-       can be applied.\r
-\r
-    ***************************************************************************\r
     ***************************************************************************\r
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-    * See http://www.OpenRTOS.com for details of the services we provide to   *\r
-    * expedite your project.                                                  *\r
+    * If you are:                                                             *\r
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+    *                                                                         *\r
+    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *\r
+    *                  http://www.FreeRTOS.org/Documentation                  *\r
+    *                                                                         *\r
+    * A pdf reference manual is also available.  Both are usually delivered   *\r
+    * to your inbox within 20 minutes to two hours when purchased between 8am *\r
+    * and 8pm GMT (although please allow up to 24 hours in case of            *\r
+    * exceptional circumstances).  Thank you for your support!                *\r
     *                                                                         *\r
     ***************************************************************************\r
-    ***************************************************************************\r
-\r
-       Please ensure to read the configuration and relevant port sections of the\r
-       online documentation.\r
 \r
-       http://www.FreeRTOS.org - Documentation, latest information, license and \r
-       contact details.\r
-\r
-       http://www.SafeRTOS.com - A version that is certified for use in safety \r
-       critical systems.\r
-\r
-       http://www.OpenRTOS.com - Commercial support, development, porting, \r
-       licensing and training services.\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
+    ***NOTE*** The exception to the GPL is included to allow you to distribute\r
+    a combined work that includes FreeRTOS without being obliged to provide the\r
+    source code for proprietary components outside of the FreeRTOS kernel.\r
+    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT\r
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or\r
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for\r
+    more details. You should have received a copy of the GNU General Public \r
+    License and the FreeRTOS license exception along with FreeRTOS; if not it \r
+    can be viewed here: http://www.freertos.org/a00114.html and also obtained \r
+    by writing to Richard Barry, contact details for whom are available on the\r
+    FreeRTOS WEB site.\r
+\r
+    1 tab == 4 spaces!\r
+\r
+    http://www.FreeRTOS.org - Documentation, latest information, license and\r
+    contact details.\r
+\r
+    http://www.SafeRTOS.com - A version that is certified for use in safety\r
+    critical systems.\r
+\r
+    http://www.OpenRTOS.com - Commercial support, development, porting,\r
+    licensing and training services.\r
 */\r
 \r
 /*-----------------------------------------------------------\r
 #include "FreeRTOS.h"\r
 #include "task.h"\r
 \r
-/* For backward compatibility, ensure configKERNEL_INTERRUPT_PRIORITY is \r
-defined.  The value should also ensure backward compatibility.  \r
+/* For backward compatibility, ensure configKERNEL_INTERRUPT_PRIORITY is\r
+defined.  The value should also ensure backward compatibility.\r
 FreeRTOS.org versions prior to V4.4.0 did not include this definition. */\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_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_CLK           0x00000004\r
 #define portNVIC_SYSTICK_INT           0x00000002\r
 #define portNVIC_SYSTICK_ENABLE                0x00000001\r
 #define portNVIC_PENDSVSET                     0x10000000\r
-#define portNVIC_PENDSV_PRI                    ( ( ( unsigned portLONG ) configKERNEL_INTERRUPT_PRIORITY ) << 16 )\r
-#define portNVIC_SYSTICK_PRI           ( ( ( unsigned portLONG ) configKERNEL_INTERRUPT_PRIORITY ) << 24 )\r
+#define portNVIC_PENDSV_PRI                    ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16 )\r
+#define portNVIC_SYSTICK_PRI           ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24 )\r
 \r
 /* Constants required to set up the initial stack. */\r
 #define portINITIAL_XPSR                       ( 0x01000000 )\r
 \r
 /* The priority used by the kernel is assigned to a variable to make access\r
 from inline assembler easier. */\r
-const unsigned portLONG ulKernelPriority = configKERNEL_INTERRUPT_PRIORITY;\r
+const unsigned long ulKernelPriority = configKERNEL_INTERRUPT_PRIORITY;\r
 \r
 /* Each task maintains its own interrupt status in the critical nesting\r
 variable. */\r
-unsigned portBASE_TYPE uxCriticalNesting = 0xaaaaaaaa;\r
+static unsigned portBASE_TYPE uxCriticalNesting = 0xaaaaaaaa;\r
 \r
-/* \r
+/*\r
  * Setup the timer to generate the tick interrupts.\r
  */\r
 static void prvSetupTimerInterrupt( void );\r
@@ -100,17 +104,18 @@ void vPortSVCHandler( void ) __attribute__ (( naked ));
 /*\r
  * Start first task is a separate function so it can be tested in isolation.\r
  */\r
-void vPortStartFirstTask( unsigned long ulValue ) __attribute__ (( naked ));\r
+void vPortStartFirstTask( void ) __attribute__ (( naked ));\r
 \r
 /*-----------------------------------------------------------*/\r
 \r
-/* \r
- * See header file for description. \r
+/*\r
+ * See header file for description.\r
  */\r
 portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE 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
@@ -118,8 +123,7 @@ portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE
        *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
-       *pxTopOfStack = 0x00000000; /* uxCriticalNesting. */\r
+       pxTopOfStack -= 8;      /* R11, R10, R9, R8, R7, R6, R5 and R4. */\r
 \r
        return pxTopOfStack;\r
 }\r
@@ -127,41 +131,39 @@ portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE
 \r
 void vPortSVCHandler( void )\r
 {\r
-       asm volatile (\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
-                                       "       ldmia r0!, {r1, r4-r11}                 \n" /* Pop the registers that are not automatically saved on exception entry and the critical nesting count. */\r
-                                       "       ldr r2, uxCriticalNestingConst2 \n" /* Restore the critical nesting count used by the task. */\r
-                                       "       str r1, [r2]                                    \n"\r
+                                       "       ldmia r0!, {r4-r11}                             \n" /* Pop the registers that are not automatically saved on exception entry and the critical nesting count. */\r
                                        "       msr psp, r0                                             \n" /* Restore the task stack pointer. */\r
                                        "       mov r0, #0                                              \n"\r
-                                       "       msr     basepri, r0                                     \n"                     \r
+                                       "       msr     basepri, r0                                     \n"\r
                                        "       orr r14, #0xd                                   \n"\r
                                        "       bx r14                                                  \n"\r
                                        "                                                                       \n"\r
                                        "       .align 2                                                \n"\r
                                        "pxCurrentTCBConst2: .word pxCurrentTCB                         \n"\r
-                                       "uxCriticalNestingConst2: .word uxCriticalNesting       \n"\r
                                );\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
-void vPortStartFirstTask( unsigned long ulValue )\r
+void vPortStartFirstTask( void )\r
 {\r
-       /* ulValue is used from the asm code, but the compiler does not know\r
-       this so remove the warning. */\r
-       ( void ) ulValue;\r
-       \r
-       asm volatile( \r
-                                       "       msr msp, r0                                                             \n" /* Set the msp back to the start of the stack. */\r
-                                       "       svc 0                                                                   \n" /* System call to start first task. */\r
+       __asm volatile(\r
+                                       " ldr r0, =0xE000ED08   \n" /* Use the NVIC offset register to locate the stack. */\r
+                                       " ldr r0, [r0]                  \n"\r
+                                       " ldr r0, [r0]                  \n"\r
+                                       " msr msp, r0                   \n" /* Set the msp back to the start of the stack. */\r
+                                       " cpsie i                               \n"\r
+                                       " svc 0                                 \n" /* System call to start first task. */\r
+                                       " nop                                   \n"\r
                                );\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
-/* \r
- * See header file for description. \r
+/*\r
+ * See header file for description.\r
  */\r
 portBASE_TYPE xPortStartScheduler( void )\r
 {\r
@@ -172,9 +174,12 @@ portBASE_TYPE xPortStartScheduler( void )
        /* Start the timer that generates the tick ISR.  Interrupts are disabled\r
        here already. */\r
        prvSetupTimerInterrupt();\r
-       \r
+\r
+       /* Initialise the critical nesting count ready for the first task. */\r
+       uxCriticalNesting = 0;\r
+\r
        /* Start the first task. */\r
-       vPortStartFirstTask( *((unsigned portLONG *) 0 ) );\r
+       vPortStartFirstTask();\r
 \r
        /* Should not get here! */\r
        return 0;\r
@@ -191,11 +196,7 @@ void vPortEndScheduler( void )
 void vPortYieldFromISR( void )\r
 {\r
        /* Set a PendSV to request a context switch. */\r
-       *(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;\r
-\r
-       /* This function is also called in response to a Yield(), so we want\r
-       the yield to occur immediately. */\r
-       portENABLE_INTERRUPTS();\r
+       *(portNVIC_INT_CTRL) = portNVIC_PENDSVSET;\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
@@ -221,53 +222,50 @@ void xPortPendSVHandler( void )
        /* This is a naked function. */\r
 \r
        __asm volatile\r
-       ( \r
-       "       mrs r0, psp                                             \n" \r
-       "                                                                       \n"\r
-       "       ldr     r3, pxCurrentTCBConst           \n" /* Get the location of the current TCB. */\r
-       "       ldr     r2, [r3]                                        \n"     \r
-       "                                                                       \n"     \r
-       "       ldr r1, uxCriticalNestingConst  \n" /* Save the remaining registers and the critical nesting count onto the task stack. */\r
-       "       ldr r1, [r1]                                    \n"\r
-       "       stmdb r0!, {r1,r4-r11}                  \n"\r
-       "       str r0, [r2]                                    \n" /* Save the new top of stack into the first member of the TCB. */\r
-       "                                                                       \n"\r
-       "       stmdb sp!, {r3, r14}                    \n" \r
-       "       bl vTaskSwitchContext                   \n"\r
-       "       ldmia sp!, {r3, r14}                    \n"\r
-       "                                                                       \n"     /* Restore the context, including the critical nesting count. */\r
-       "       ldr r1, [r3]                                    \n" \r
-       "       ldr r2, uxCriticalNestingConst  \n"\r
-       "       ldr r0, [r1]                                    \n" /* The first item in pxCurrentTCB is the task top of stack. */\r
-       "       ldmia r0!, {r1, r4-r11}                 \n" /* Pop the registers and the critical nesting count. */\r
-       "       str r1, [r2]                                    \n" /* Save the new critical nesting value into ulCriticalNesting. */ \r
-       "       msr psp, r0                                             \n" \r
-       "       orr r14, #0xd                                   \n"\r
-       "                                                                       \n"     /* Exit with interrupts in the state required by the task. */   \r
-       "       cbnz r1, sv_disable_interrupts  \n" /* If the nesting count is greater than 0 we need to exit with interrupts masked. */\r
-       "       bx r14                                                  \n"\r
-       "                                                                       \n"\r
-       "sv_disable_interrupts:                         \n" \r
-       "       ldr r1, =ulKernelPriority               \n"\r
-       "       ldr r1, [r1]                                    \n"\r
-       "       msr     basepri, r1                                     \n"\r
-       "       bx r14                                                  \n"\r
-       "                                                                       \n"\r
-       "       .align 2                                                \n"\r
-       "pxCurrentTCBConst: .word pxCurrentTCB                          \n"\r
-       "uxCriticalNestingConst: .word uxCriticalNesting        \n"\r
+       (\r
+       "       mrs r0, psp                                                     \n"\r
+       "                                                                               \n"\r
+       "       ldr     r3, pxCurrentTCBConst                   \n" /* Get the location of the current TCB. */\r
+       "       ldr     r2, [r3]                                                \n"\r
+       "                                                                               \n"\r
+       "       stmdb r0!, {r4-r11}                                     \n" /* Save the remaining registers. */\r
+       "       str r0, [r2]                                            \n" /* Save the new top of stack into the first member of the TCB. */\r
+       "                                                                               \n"\r
+       "       stmdb sp!, {r3, r14}                            \n"\r
+       "       mov r0, %0                                                      \n"\r
+       "       msr basepri, r0                                         \n"\r
+       "       bl vTaskSwitchContext                           \n"\r
+       "       mov r0, #0                                                      \n"\r
+       "       msr basepri, r0                                         \n"\r
+       "       ldmia sp!, {r3, r14}                            \n"\r
+       "                                                                               \n"     /* Restore the context, including the critical nesting count. */\r
+       "       ldr r1, [r3]                                            \n"\r
+       "       ldr r0, [r1]                                            \n" /* The first item in pxCurrentTCB is the task top of stack. */\r
+       "       ldmia r0!, {r4-r11}                                     \n" /* Pop the registers. */\r
+       "       msr psp, r0                                                     \n"\r
+       "       bx r14                                                          \n"\r
+       "                                                                               \n"\r
+       "       .align 2                                                        \n"\r
+       "pxCurrentTCBConst: .word pxCurrentTCB  \n"\r
+       ::"i"(configMAX_SYSCALL_INTERRUPT_PRIORITY)\r
        );\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
 void xPortSysTickHandler( void )\r
 {\r
+unsigned long ulDummy;\r
+\r
        /* If using preemption, also force a context switch. */\r
        #if configUSE_PREEMPTION == 1\r
-               *(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;     \r
+               *(portNVIC_INT_CTRL) = portNVIC_PENDSVSET;\r
        #endif\r
 \r
-       vTaskIncrementTick();\r
+       ulDummy = portSET_INTERRUPT_MASK_FROM_ISR();\r
+       {\r
+               vTaskIncrementTick();\r
+       }\r
+       portCLEAR_INTERRUPT_MASK_FROM_ISR( ulDummy );\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r