diff options
Diffstat (limited to 'app/platform/stm32f0-gcc/freertos/port.c')
| -rw-r--r-- | app/platform/stm32f0-gcc/freertos/port.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/app/platform/stm32f0-gcc/freertos/port.c b/app/platform/stm32f0-gcc/freertos/port.c new file mode 100644 index 0000000..423ae1e --- /dev/null +++ b/app/platform/stm32f0-gcc/freertos/port.c @@ -0,0 +1,368 @@ +/*
+ FreeRTOS V8.2.1 - Copyright (C) 2015 Real Time Engineers Ltd.
+ All rights reserved
+
+ VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
+
+ This file is part of the FreeRTOS distribution.
+
+ FreeRTOS is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License (version 2) as published by the
+ Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
+
+ ***************************************************************************
+ >>! NOTE: The modification to the GPL is included to allow you to !<<
+ >>! distribute a combined work that includes FreeRTOS without being !<<
+ >>! obliged to provide the source code for proprietary components !<<
+ >>! outside of the FreeRTOS kernel. !<<
+ ***************************************************************************
+
+ FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ FOR A PARTICULAR PURPOSE. Full license text is available on the following
+ link: http://www.freertos.org/a00114.html
+
+ ***************************************************************************
+ * *
+ * FreeRTOS provides completely free yet professionally developed, *
+ * robust, strictly quality controlled, supported, and cross *
+ * platform software that is more than just the market leader, it *
+ * is the industry's de facto standard. *
+ * *
+ * Help yourself get started quickly while simultaneously helping *
+ * to support the FreeRTOS project by purchasing a FreeRTOS *
+ * tutorial book, reference manual, or both: *
+ * http://www.FreeRTOS.org/Documentation *
+ * *
+ ***************************************************************************
+
+ http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading
+ the FAQ page "My application does not run, what could be wrong?". Have you
+ defined configASSERT()?
+
+ http://www.FreeRTOS.org/support - In return for receiving this top quality
+ embedded software for free we request you assist our global community by
+ participating in the support forum.
+
+ http://www.FreeRTOS.org/training - Investing in training allows your team to
+ be as productive as possible as early as possible. Now you can receive
+ FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
+ Ltd, and the world's leading authority on the world's leading RTOS.
+
+ http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
+ including FreeRTOS+Trace - an indispensable productivity tool, a DOS
+ compatible FAT file system, and our tiny thread aware UDP/IP stack.
+
+ http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
+ Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.
+
+ http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
+ Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS
+ licenses offer ticketed support, indemnification and commercial middleware.
+
+ http://www.SafeRTOS.com - High Integrity Systems also provide a safety
+ engineered and independently SIL3 certified version for use in safety and
+ mission critical applications that require provable dependability.
+
+ 1 tab == 4 spaces!
+*/
+
+/*-----------------------------------------------------------
+ * Implementation of functions defined in portable.h for the ARM CM0 port.
+ *----------------------------------------------------------*/
+
+/* Scheduler includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+/* Constants required to manipulate the NVIC. */
+#define portNVIC_SYSTICK_CTRL ( ( volatile uint32_t *) 0xe000e010 )
+#define portNVIC_SYSTICK_LOAD ( ( volatile uint32_t *) 0xe000e014 )
+#define portNVIC_INT_CTRL ( ( volatile uint32_t *) 0xe000ed04 )
+#define portNVIC_SYSPRI2 ( ( volatile uint32_t *) 0xe000ed20 )
+#define portNVIC_SYSTICK_CLK 0x00000004
+#define portNVIC_SYSTICK_INT 0x00000002
+#define portNVIC_SYSTICK_ENABLE 0x00000001
+#define portNVIC_PENDSVSET 0x10000000
+#define portMIN_INTERRUPT_PRIORITY ( 255UL )
+#define portNVIC_PENDSV_PRI ( portMIN_INTERRUPT_PRIORITY << 16UL )
+#define portNVIC_SYSTICK_PRI ( portMIN_INTERRUPT_PRIORITY << 24UL )
+
+/* Constants required to set up the initial stack. */
+#define portINITIAL_XPSR ( 0x01000000 )
+
+/* Let the user override the pre-loading of the initial LR with the address of
+prvTaskExitError() in case is messes up unwinding of the stack in the
+debugger. */
+#ifdef configTASK_RETURN_ADDRESS
+ #define portTASK_RETURN_ADDRESS configTASK_RETURN_ADDRESS
+#else
+ #define portTASK_RETURN_ADDRESS prvTaskExitError
+#endif
+
+/* Each task maintains its own interrupt status in the critical nesting
+variable. */
+static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;
+
+/*
+ * Setup the timer to generate the tick interrupts.
+ */
+static void prvSetupTimerInterrupt( void );
+
+/*
+ * Exception handlers.
+ */
+void PENDSV_handler( void ) __attribute__ (( naked ));
+void SYSTICK_handler( void );
+void SVCALL_handler( void );
+
+/*
+ * Start first task is a separate function so it can be tested in isolation.
+ */
+static void vPortStartFirstTask( void ) __attribute__ (( naked ));
+
+/*
+ * Used to catch tasks that attempt to return from their implementing function.
+ */
+static void prvTaskExitError( void );
+
+/*-----------------------------------------------------------*/
+
+/*
+ * See header file for description.
+ */
+StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
+{
+ /* Simulate the stack frame as it would be created by a context switch
+ interrupt. */
+ pxTopOfStack--; /* Offset added to account for the way the MCU uses the stack on entry/exit of interrupts. */
+ *pxTopOfStack = portINITIAL_XPSR; /* xPSR */
+ pxTopOfStack--;
+ *pxTopOfStack = ( StackType_t ) pxCode; /* PC */
+ pxTopOfStack--;
+ *pxTopOfStack = ( StackType_t ) portTASK_RETURN_ADDRESS; /* LR */
+ pxTopOfStack -= 5; /* R12, R3, R2 and R1. */
+ *pxTopOfStack = ( StackType_t ) pvParameters; /* R0 */
+ pxTopOfStack -= 8; /* R11..R4. */
+
+ return pxTopOfStack;
+}
+/*-----------------------------------------------------------*/
+
+static void prvTaskExitError( void )
+{
+ /* A function that implements a task must not exit or attempt to return to
+ its caller as there is nothing to return to. If a task wants to exit it
+ should instead call vTaskDelete( NULL ).
+
+ Artificially force an assert() to be triggered if configASSERT() is
+ defined, then stop here so application writers can catch the error. */
+ configASSERT( uxCriticalNesting == ~0UL );
+ portDISABLE_INTERRUPTS();
+ for( ;; );
+}
+/*-----------------------------------------------------------*/
+
+void SVCALL_handler( void )
+{
+ /* This function is no longer used, but retained for backward
+ compatibility. */
+}
+/*-----------------------------------------------------------*/
+
+void vPortStartFirstTask( void )
+{
+ /* The MSP stack is not reset as, unlike on M3/4 parts, there is no vector
+ table offset register that can be used to locate the initial stack value.
+ Not all M0 parts have the application vector table at address 0. */
+ __asm volatile(
+ " ldr r2, pxCurrentTCBConst2 \n" /* Obtain location of pxCurrentTCB. */
+ " ldr r3, [r2] \n"
+ " ldr r0, [r3] \n" /* The first item in pxCurrentTCB is the task top of stack. */
+ " add r0, #32 \n" /* Discard everything up to r0. */
+ " msr psp, r0 \n" /* This is now the new top of stack to use in the task. */
+ " movs r0, #2 \n" /* Switch to the psp stack. */
+ " msr CONTROL, r0 \n"
+ " pop {r0-r5} \n" /* Pop the registers that are saved automatically. */
+ " mov lr, r5 \n" /* lr is now in r5. */
+ " cpsie i \n" /* The first task has its context and interrupts can be enabled. */
+ " pop {pc} \n" /* Finally, pop the PC to jump to the user defined task code. */
+ " \n"
+ " .align 2 \n"
+ "pxCurrentTCBConst2: .word pxCurrentTCB "
+ );
+}
+/*-----------------------------------------------------------*/
+
+/*
+ * See header file for description.
+ */
+BaseType_t xPortStartScheduler( void )
+{
+ /* Make PendSV, CallSV and SysTick the same priroity as the kernel. */
+ *(portNVIC_SYSPRI2) |= portNVIC_PENDSV_PRI;
+ *(portNVIC_SYSPRI2) |= portNVIC_SYSTICK_PRI;
+
+ /* Start the timer that generates the tick ISR. Interrupts are disabled
+ here already. */
+ prvSetupTimerInterrupt();
+
+ /* Initialise the critical nesting count ready for the first task. */
+ uxCriticalNesting = 0;
+
+ /* Start the first task. */
+ vPortStartFirstTask();
+
+ /* Should never get here as the tasks will now be executing! Call the task
+ exit error function to prevent compiler warnings about a static function
+ not being called in the case that the application writer overrides this
+ functionality by defining configTASK_RETURN_ADDRESS. */
+ prvTaskExitError();
+
+ /* Should not get here! */
+ return 0;
+}
+/*-----------------------------------------------------------*/
+
+void vPortEndScheduler( void )
+{
+ /* Not implemented in ports where there is nothing to return to.
+ Artificially force an assert. */
+ configASSERT( uxCriticalNesting == 1000UL );
+}
+/*-----------------------------------------------------------*/
+
+void vPortYield( void )
+{
+ /* Set a PendSV to request a context switch. */
+ *( portNVIC_INT_CTRL ) = portNVIC_PENDSVSET;
+
+ /* Barriers are normally not required but do ensure the code is completely
+ within the specified behaviour for the architecture. */
+ __asm volatile( "dsb" );
+ __asm volatile( "isb" );
+}
+/*-----------------------------------------------------------*/
+
+void vPortEnterCritical( void )
+{
+ portDISABLE_INTERRUPTS();
+ uxCriticalNesting++;
+ __asm volatile( "dsb" );
+ __asm volatile( "isb" );
+}
+/*-----------------------------------------------------------*/
+
+void vPortExitCritical( void )
+{
+ configASSERT( uxCriticalNesting );
+ uxCriticalNesting--;
+ if( uxCriticalNesting == 0 )
+ {
+ portENABLE_INTERRUPTS();
+ }
+}
+/*-----------------------------------------------------------*/
+
+uint32_t ulSetInterruptMaskFromISR( void )
+{
+ __asm volatile(
+ " mrs r0, PRIMASK \n"
+ " cpsid i \n"
+ " bx lr "
+ );
+
+ /* To avoid compiler warnings. This line will never be reached. */
+ return 0;
+}
+/*-----------------------------------------------------------*/
+
+void vClearInterruptMaskFromISR( uint32_t ulMask )
+{
+ __asm volatile(
+ " msr PRIMASK, r0 \n"
+ " bx lr "
+ );
+
+ /* Just to avoid compiler warning. */
+ ( void ) ulMask;
+}
+/*-----------------------------------------------------------*/
+
+void PENDSV_handler( void )
+{
+ /* This is a naked function. */
+
+ __asm volatile
+ (
+ " mrs r0, psp \n"
+ " \n"
+ " ldr r3, pxCurrentTCBConst \n" /* Get the location of the current TCB. */
+ " ldr r2, [r3] \n"
+ " \n"
+ " sub r0, r0, #32 \n" /* Make space for the remaining low registers. */
+ " str r0, [r2] \n" /* Save the new top of stack. */
+ " stmia r0!, {r4-r7} \n" /* Store the low registers that are not saved automatically. */
+ " mov r4, r8 \n" /* Store the high registers. */
+ " mov r5, r9 \n"
+ " mov r6, r10 \n"
+ " mov r7, r11 \n"
+ " stmia r0!, {r4-r7} \n"
+ " \n"
+ " push {r3, r14} \n"
+ " cpsid i \n"
+ " bl vTaskSwitchContext \n"
+ " cpsie i \n"
+ " pop {r2, r3} \n" /* lr goes in r3. r2 now holds tcb pointer. */
+ " \n"
+ " ldr r1, [r2] \n"
+ " ldr r0, [r1] \n" /* The first item in pxCurrentTCB is the task top of stack. */
+ " add r0, r0, #16 \n" /* Move to the high registers. */
+ " ldmia r0!, {r4-r7} \n" /* Pop the high registers. */
+ " mov r8, r4 \n"
+ " mov r9, r5 \n"
+ " mov r10, r6 \n"
+ " mov r11, r7 \n"
+ " \n"
+ " msr psp, r0 \n" /* Remember the new top of stack for the task. */
+ " \n"
+ " sub r0, r0, #32 \n" /* Go back for the low registers that are not automatically restored. */
+ " ldmia r0!, {r4-r7} \n" /* Pop low registers. */
+ " \n"
+ " bx r3 \n"
+ " \n"
+ " .align 2 \n"
+ "pxCurrentTCBConst: .word pxCurrentTCB "
+ );
+}
+/*-----------------------------------------------------------*/
+
+void SYSTICK_handler( void )
+{
+uint32_t ulPreviousMask;
+
+ ulPreviousMask = portSET_INTERRUPT_MASK_FROM_ISR();
+ {
+ /* Increment the RTOS tick. */
+ if( xTaskIncrementTick() != pdFALSE )
+ {
+ /* Pend a context switch. */
+ *(portNVIC_INT_CTRL) = portNVIC_PENDSVSET;
+ }
+ }
+ portCLEAR_INTERRUPT_MASK_FROM_ISR( ulPreviousMask );
+}
+/*-----------------------------------------------------------*/
+
+/*
+ * Setup the systick timer to generate the tick interrupts at the required
+ * frequency.
+ */
+void prvSetupTimerInterrupt( void )
+{
+ /* Configure SysTick to interrupt at the requested rate. */
+ *(portNVIC_SYSTICK_LOAD) = ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;
+ *(portNVIC_SYSTICK_CTRL) = portNVIC_SYSTICK_CLK | portNVIC_SYSTICK_INT | portNVIC_SYSTICK_ENABLE;
+}
+/*-----------------------------------------------------------*/
+
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