+/*\r
+ FreeRTOS V7.4.2 - Copyright (C) 2013 Real Time Engineers Ltd.\r
+\r
+ FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT\r
+ http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.\r
+\r
+ ***************************************************************************\r
+ * *\r
+ * FreeRTOS tutorial books are available in pdf and paperback. *\r
+ * Complete, revised, and edited pdf reference manuals are also *\r
+ * available. *\r
+ * *\r
+ * Purchasing FreeRTOS documentation will not only help you, by *\r
+ * ensuring you get running as quickly as possible and with an *\r
+ * in-depth knowledge of how to use FreeRTOS, it will also help *\r
+ * the FreeRTOS project to continue with its mission of providing *\r
+ * professional grade, cross platform, de facto standard solutions *\r
+ * for microcontrollers - completely free of charge! *\r
+ * *\r
+ * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *\r
+ * *\r
+ * Thank you for using FreeRTOS, and thank you for your support! *\r
+ * *\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
+\r
+ >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to\r
+ distribute a combined work that includes FreeRTOS without being obliged to\r
+ provide the source code for proprietary components outside of the FreeRTOS\r
+ kernel.\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. See the GNU General Public License for more\r
+ details. You should have received a copy of the GNU General Public License\r
+ and the FreeRTOS license exception along with FreeRTOS; if not it can be\r
+ viewed here: http://www.freertos.org/a00114.html and also obtained by\r
+ writing to Real Time Engineers Ltd., contact details for whom are available\r
+ on the FreeRTOS WEB site.\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
+ * *\r
+ * http://www.FreeRTOS.org/FAQHelp.html *\r
+ * *\r
+ ***************************************************************************\r
+\r
+\r
+ http://www.FreeRTOS.org - Documentation, books, training, latest versions,\r
+ license and Real Time Engineers Ltd. contact details.\r
+\r
+ http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,\r
+ including FreeRTOS+Trace - an indispensable productivity tool, and our new\r
+ fully thread aware and reentrant UDP/IP stack.\r
+\r
+ http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High\r
+ Integrity Systems, who sell the code with commercial support,\r
+ indemnification and middleware, under the OpenRTOS brand.\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
+ mission critical applications that require provable dependability.\r
+*/\r
+\r
+/* Standard includes. */\r
+#include <stdlib.h>\r
+\r
+/* Scheduler includes. */\r
+#include "FreeRTOS.h"\r
+#include "task.h"\r
+\r
+#ifndef configINTERRUPT_CONTROLLER_BASE_ADDRESS\r
+ #error configINTERRUPT_CONTROLLER_BASE_ADDRESS must be defined. See http://www.freertos.org/Using-FreeRTOS-on-Cortex-A-Embedded-Processors.html\r
+#endif\r
+\r
+#ifndef configINTERRUPT_CONTROLLER_CPU_INTERFACE_OFFSET\r
+ #error configINTERRUPT_CONTROLLER_CPU_INTERFACE_OFFSET must be defined. See http://www.freertos.org/Using-FreeRTOS-on-Cortex-A-Embedded-Processors.html\r
+#endif\r
+\r
+#ifndef configUNIQUE_INTERRUPT_PRIORITIES\r
+ #error configUNIQUE_INTERRUPT_PRIORITIES must be defined. See http://www.freertos.org/Using-FreeRTOS-on-Cortex-A-Embedded-Processors.html\r
+#endif\r
+\r
+#ifndef configSETUP_TICK_INTERRUPT\r
+ #error configSETUP_TICK_INTERRUPT() must be defined. See http://www.freertos.org/Using-FreeRTOS-on-Cortex-A-Embedded-Processors.html\r
+#endif /* configSETUP_TICK_INTERRUPT */\r
+\r
+#ifndef configMAX_API_CALL_INTERRUPT_PRIORITY\r
+ #error configMAX_API_CALL_INTERRUPT_PRIORITY must be defined. See http://www.freertos.org/Using-FreeRTOS-on-Cortex-A-Embedded-Processors.html\r
+#endif\r
+\r
+#if configMAX_API_CALL_INTERRUPT_PRIORITY == 0\r
+ #error configMAX_API_CALL_INTERRUPT_PRIORITY must not be set to 0\r
+#endif\r
+\r
+#if configMAX_API_CALL_INTERRUPT_PRIORITY > configUNIQUE_INTERRUPT_PRIORITIES\r
+ #error configMAX_API_CALL_INTERRUPT_PRIORITY must be less than or equal to configUNIQUE_INTERRUPT_PRIORITIES as the lower the numeric priority value the higher the logical interrupt priority\r
+#endif\r
+\r
+#if configUSE_PORT_OPTIMISED_TASK_SELECTION == 1\r
+ /* Check the configuration. */\r
+ #if( configMAX_PRIORITIES > 32 )\r
+ #error configUSE_PORT_OPTIMISED_TASK_SELECTION can only be set to 1 when configMAX_PRIORITIES is less than or equal to 32. It is very rare that a system requires more than 10 to 15 difference priorities as tasks that share a priority will time slice.\r
+ #endif\r
+#endif /* configUSE_PORT_OPTIMISED_TASK_SELECTION */\r
+\r
+/* In case security extensions are implemented. */\r
+#if configMAX_API_CALL_INTERRUPT_PRIORITY <= ( configUNIQUE_INTERRUPT_PRIORITIES / 2 )\r
+ #error configMAX_API_CALL_INTERRUPT_PRIORITY must be greater than ( configUNIQUE_INTERRUPT_PRIORITIES / 2 )\r
+#endif\r
+\r
+/* The number of bits to shift for an interrupt priority is dependent on the\r
+number of bits implemented by the interrupt controller. */\r
+#if configUNIQUE_INTERRUPT_PRIORITIES == 16\r
+ #define portPRIORITY_SHIFT 4\r
+#elif configUNIQUE_INTERRUPT_PRIORITIES == 32\r
+ #define portPRIORITY_SHIFT 3\r
+#elif configUNIQUE_INTERRUPT_PRIORITIES == 64\r
+ #define portPRIORITY_SHIFT 2\r
+#elif configUNIQUE_INTERRUPT_PRIORITIES == 128\r
+ #define portPRIORITY_SHIFT 1\r
+#elif configUNIQUE_INTERRUPT_PRIORITIES == 256\r
+ #define portPRIORITY_SHIFT 0\r
+#else\r
+ #error Invalid configUNIQUE_INTERRUPT_PRIORITIES setting. configUNIQUE_INTERRUPT_PRIORITIES must be set to the number of unique priorities implemented by the target hardware\r
+#endif\r
+\r
+/* A critical section is exited when the critical section nesting count reaches\r
+this value. */\r
+#define portNO_CRITICAL_NESTING ( ( unsigned long ) 0 )\r
+\r
+/* In all GICs 255 can be written to the priority mask register to unmask all\r
+(but the lowest) interrupt priority. */\r
+#define portUNMASK_VALUE ( 0xFF )\r
+\r
+/* Tasks are not created with a floating point context, but can be given a\r
+floating point context after they have been created. A variable is stored as\r
+part of the tasks context that holds portNO_FLOATING_POINT_CONTEXT if the task\r
+does not have an FPU context, or any other value if the task does have an FPU\r
+context. */\r
+#define portNO_FLOATING_POINT_CONTEXT ( ( portSTACK_TYPE ) 0 )\r
+\r
+/* Interrupt controller access addresses. */\r
+#define portICCPMR_PRIORITY_MASK_OFFSET ( 0x04 )\r
+#define portICCIAR_INTERRUPT_ACKNOWLEDGE_OFFSET ( 0x0C )\r
+#define portICCEOIR_END_OF_INTERRUPT_OFFSET ( 0x10 )\r
+#define portINTERRUPT_CONTROLLER_CPU_INTERFACE_ADDRESS ( configINTERRUPT_CONTROLLER_BASE_ADDRESS + configINTERRUPT_CONTROLLER_CPU_INTERFACE_OFFSET )\r
+#define portICCPMR_PRIORITY_MASK_REGISTER ( *( ( volatile unsigned long * ) ( portINTERRUPT_CONTROLLER_CPU_INTERFACE_ADDRESS + portICCPMR_PRIORITY_MASK_OFFSET ) ) )\r
+#define portICCIAR_INTERRUPT_ACKNOWLEDGE_REGISTER_ADDRESS ( portINTERRUPT_CONTROLLER_CPU_INTERFACE_ADDRESS + portICCIAR_INTERRUPT_ACKNOWLEDGE_OFFSET )\r
+#define portICCEOIR_END_OF_INTERRUPT_REGISTER_ADDRESS ( portINTERRUPT_CONTROLLER_CPU_INTERFACE_ADDRESS + portICCEOIR_END_OF_INTERRUPT_OFFSET )\r
+#define portICCPMR_PRIORITY_MASK_REGISTER_ADDRESS ( portINTERRUPT_CONTROLLER_CPU_INTERFACE_ADDRESS + portICCPMR_PRIORITY_MASK_OFFSET )\r
+\r
+/* Constants required to setup the initial task context. */\r
+#define portINITIAL_SPSR ( ( portSTACK_TYPE ) 0x1f ) /* System mode, ARM mode, interrupts enabled. */\r
+#define portTHUMB_MODE_BIT ( ( portSTACK_TYPE ) 0x20 )\r
+#define portINTERRUPT_ENABLE_BIT ( 0x80UL )\r
+#define portTHUMB_MODE_ADDRESS ( 0x01UL )\r
+\r
+/* Masks all bits in the APSR other than the mode bits. */\r
+#define portAPSR_MODE_BITS_MASK ( 0x1F )\r
+\r
+/* The value of the mode bits in the APSR when the CPU is executing in user\r
+mode. */\r
+#define portAPSR_USER_MODE ( 0x10 )\r
+\r
+/* Macro to unmask all interrupt priorities. */\r
+#define portCLEAR_INTERRUPT_MASK() \\r
+{ \\r
+ __disable_irq(); \\r
+ portICCPMR_PRIORITY_MASK_REGISTER = portUNMASK_VALUE; \\r
+ __asm( "DSB \n" \\r
+ "ISB \n" ); \\r
+ __enable_irq(); \\r
+}\r
+\r
+/*-----------------------------------------------------------*/\r
+\r
+/*\r
+ * Starts the first task executing. This function is necessarily written in\r
+ * assembly code so is implemented in portASM.s.\r
+ */\r
+extern void vPortRestoreTaskContext( void );\r
+\r
+/*-----------------------------------------------------------*/\r
+\r
+/* A variable is used to keep track of the critical section nesting. This\r
+variable has to be stored as part of the task context and must be initialised to\r
+a non zero value to ensure interrupts don't inadvertently become unmasked before\r
+the scheduler starts. As it is stored as part of the task context it will\r
+automatically be set to 0 when the first task is started. */\r
+volatile unsigned long ulCriticalNesting = 9999UL;\r
+\r
+/* The value to be written to the interrupt controllers priority mask register\r
+to mask interrupts that can use the FreeRTOS API without masking higher priority\r
+interrupts. */\r
+const unsigned long ulPortAPIPriorityMask = ( configMAX_API_CALL_INTERRUPT_PRIORITY << portPRIORITY_SHIFT );\r
+\r
+/* Used to pass constants into the ASM code. The address at which variables are\r
+placed is the constant value so indirect loads in the asm code are not\r
+required. */\r
+unsigned long ulICCIAR __attribute__( ( at( portICCIAR_INTERRUPT_ACKNOWLEDGE_REGISTER_ADDRESS ) ) );\r
+unsigned long ulICCEOIR __attribute__( ( at( portICCEOIR_END_OF_INTERRUPT_REGISTER_ADDRESS ) ) );\r
+unsigned long ulICCPMR __attribute__( ( at( portICCPMR_PRIORITY_MASK_REGISTER_ADDRESS ) ) );\r
+unsigned long ulAsmAPIPriorityMask __attribute__( ( at( configMAX_API_CALL_INTERRUPT_PRIORITY << portPRIORITY_SHIFT ) ) );\r
+\r
+/* Saved as part of the task context. If ulPortTaskHasFPUContext is non-zero then\r
+a floating point context must be saved and restored for the task. */\r
+unsigned long ulPortTaskHasFPUContext = pdFALSE;\r
+\r
+/* Set to 1 to pend a context switch from an ISR. */\r
+unsigned long ulPortYieldRequired = pdFALSE;\r
+\r
+/* Counts the interrupt nesting depth. A context switch is only performed if\r
+if the nesting depth is 0. */\r
+unsigned long ulPortInterruptNesting = 0UL;\r
+\r
+/*-----------------------------------------------------------*/\r
+\r
+/*\r
+ * See header file for description.\r
+ */\r
+portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )\r
+{\r
+ /* Setup the initial stack of the task. The stack is set exactly as\r
+ expected by the portRESTORE_CONTEXT() macro.\r
+\r
+ The fist real value on the stack is the status register, which is set for\r
+ system mode, with interrupts enabled. A few NULLs are added first to ensure\r
+ GDB does not try decoding a non-existent return address. */\r
+ *pxTopOfStack = NULL;\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = NULL;\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = NULL;\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) portINITIAL_SPSR;\r
+\r
+ if( ( ( unsigned long ) pxCode & portTHUMB_MODE_ADDRESS ) != 0x00UL )\r
+ {\r
+ /* The task will start in THUMB mode. */\r
+ *pxTopOfStack |= portTHUMB_MODE_BIT;\r
+ }\r
+\r
+ pxTopOfStack--;\r
+\r
+ /* Next the return address, which in this case is the start of the task. */\r
+ *pxTopOfStack = ( portSTACK_TYPE ) pxCode;\r
+ pxTopOfStack--;\r
+\r
+ /* Next all the registers other than the stack pointer. */\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0xaaaaaaaa; /* R14 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x12121212; /* R12 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x11111111; /* R11 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x10101010; /* R10 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x09090909; /* R9 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x08080808; /* R8 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x07070707; /* R7 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x06060606; /* R6 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x05050505; /* R5 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x04040404; /* R4 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x03030303; /* R3 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x02020202; /* R2 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) 0x01010101; /* R1 */\r
+ pxTopOfStack--;\r
+ *pxTopOfStack = ( portSTACK_TYPE ) pvParameters; /* R0 */\r
+ pxTopOfStack--;\r
+\r
+ /* The task will start with a critical nesting count of 0 as interrupts are\r
+ enabled. */\r
+ *pxTopOfStack = portNO_CRITICAL_NESTING;\r
+ pxTopOfStack--;\r
+\r
+ /* The task will start without a floating point context. A task that uses\r
+ the floating point hardware must call vPortTaskUsesFPU() before executing\r
+ any floating point instructions. */\r
+ *pxTopOfStack = portNO_FLOATING_POINT_CONTEXT;\r
+\r
+ return pxTopOfStack;\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+portBASE_TYPE xPortStartScheduler( void )\r
+{\r
+unsigned long ulAPSR;\r
+\r
+ /* Only continue if the CPU is not in User mode. The CPU must be in a\r
+ Privileged mode for the scheduler to start. */\r
+ __asm( "MRS ulAPSR, APSR" );\r
+ ulAPSR &= portAPSR_MODE_BITS_MASK;\r
+ configASSERT( ulAPSR != portAPSR_USER_MODE );\r
+\r
+ if( ulAPSR != portAPSR_USER_MODE )\r
+ {\r
+ /* Start the timer that generates the tick ISR. */\r
+ configSETUP_TICK_INTERRUPT();\r
+\r
+ __enable_irq();\r
+ vPortRestoreTaskContext();\r
+ }\r
+\r
+ /* Will only get here if xTaskStartScheduler() was called with the CPU in\r
+ a non-privileged mode. */\r
+ return 0;\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+void vPortEndScheduler( void )\r
+{\r
+ /* It is unlikely that the ARM port will require this function as there\r
+ is nothing to return to. */\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+void vPortEnterCritical( void )\r
+{\r
+ /* Disable interrupts as per portDISABLE_INTERRUPTS(); */\r
+ ulPortSetInterruptMask();\r
+\r
+ /* Now interrupts are disabled ulCriticalNesting can be accessed\r
+ directly. Increment ulCriticalNesting to keep a count of how many times\r
+ portENTER_CRITICAL() has been called. */\r
+ ulCriticalNesting++;\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+void vPortExitCritical( void )\r
+{\r
+ if( ulCriticalNesting > portNO_CRITICAL_NESTING )\r
+ {\r
+ /* Decrement the nesting count as the critical section is being\r
+ exited. */\r
+ ulCriticalNesting--;\r
+\r
+ /* If the nesting level has reached zero then all interrupt\r
+ priorities must be re-enabled. */\r
+ if( ulCriticalNesting == portNO_CRITICAL_NESTING )\r
+ {\r
+ /* Critical nesting has reached zero so all interrupt priorities\r
+ should be unmasked. */\r
+ portCLEAR_INTERRUPT_MASK();\r
+ }\r
+ }\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+void FreeRTOS_Tick_Handler( void )\r
+{\r
+ /* Set interrupt mask before altering scheduler structures. The tick\r
+ handler runs at the lowest priority, so interrupts cannot already be masked,\r
+ so there is no need to save and restore the current mask value. */\r
+ __disable_irq();\r
+ portICCPMR_PRIORITY_MASK_REGISTER = ulPortAPIPriorityMask;\r
+ __asm( "DSB \n"\r
+ "ISB \n" );\r
+ __enable_irq();\r
+\r
+ /* Increment the RTOS tick. */\r
+ if( xTaskIncrementTick() != pdFALSE )\r
+ {\r
+ ulPortYieldRequired = pdTRUE;\r
+ }\r
+\r
+ /* Ensure all interrupt priorities are active again. */\r
+ portCLEAR_INTERRUPT_MASK();\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+void vPortTaskUsesFPU( void )\r
+{\r
+unsigned long ulInitialFPSCR = 0;\r
+\r
+ /* A task is registering the fact that it needs an FPU context. Set the\r
+ FPU flag (which is saved as part of the task context). */\r
+ ulPortTaskHasFPUContext = pdTRUE;\r
+\r
+ /* Initialise the floating point status register. */\r
+ __asm( "FMXR FPSCR, ulInitialFPSCR" );\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+void vPortClearInterruptMask( unsigned long ulNewMaskValue )\r
+{\r
+ if( ulNewMaskValue == pdFALSE )\r
+ {\r
+ portCLEAR_INTERRUPT_MASK();\r
+ }\r
+}\r
+/*-----------------------------------------------------------*/\r
+\r
+unsigned long ulPortSetInterruptMask( void )\r
+{\r
+unsigned long ulReturn;\r
+\r
+ __disable_irq();\r
+ if( portICCPMR_PRIORITY_MASK_REGISTER == ulPortAPIPriorityMask )\r
+ {\r
+ /* Interrupts were already masked. */\r
+ ulReturn = pdTRUE;\r
+ }\r
+ else\r
+ {\r
+ ulReturn = pdFALSE;\r
+ portICCPMR_PRIORITY_MASK_REGISTER = ulPortAPIPriorityMask;\r
+ __asm( "DSB \n"\r
+ "ISB \n" );\r
+ }\r
+ __enable_irq();\r
+\r
+ return ulReturn;\r
+}\r
+\r
+\r