359 lines
11 KiB
C
359 lines
11 KiB
C
/*
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* FreeRTOS Kernel V10.2.1
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* Copyright (C) 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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* http://www.FreeRTOS.org
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* http://aws.amazon.com/freertos
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*
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* 1 tab == 4 spaces!
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*/
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/*-----------------------------------------------------------
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* Implementation of functions defined in portable.h for the SH2A port.
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*----------------------------------------------------------*/
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/* Scheduler includes. */
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#include "FreeRTOS.h"
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#include "task.h"
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/* Library includes. */
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#include "string.h"
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/* Hardware specifics. */
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#include "iodefine.h"
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/*-----------------------------------------------------------*/
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/* Tasks should start with interrupts enabled and in Supervisor mode, therefore
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PSW is set with U and I set, and PM and IPL clear. */
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#define portINITIAL_PSW ( ( StackType_t ) 0x00030000 )
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#define portINITIAL_FPSW ( ( StackType_t ) 0x00000100 )
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/* These macros allow a critical section to be added around the call to
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xTaskIncrementTick(), which is only ever called from interrupts at the kernel
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priority - ie a known priority. Therefore these local macros are a slight
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optimisation compared to calling the global SET/CLEAR_INTERRUPT_MASK macros,
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which would require the old IPL to be read first and stored in a local variable. */
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#define portDISABLE_INTERRUPTS_FROM_KERNEL_ISR() __asm volatile ( "MVTIPL %0" ::"i"(configMAX_SYSCALL_INTERRUPT_PRIORITY) )
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#define portENABLE_INTERRUPTS_FROM_KERNEL_ISR() __asm volatile ( "MVTIPL %0" ::"i"(configKERNEL_INTERRUPT_PRIORITY) )
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/*-----------------------------------------------------------*/
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/*
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* Function to start the first task executing - written in asm code as direct
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* access to registers is required.
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*/
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static void prvStartFirstTask( void ) __attribute__((naked));
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/*
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* Software interrupt handler. Performs the actual context switch (saving and
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* restoring of registers). Written in asm code as direct register access is
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* required.
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*/
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void vSoftwareInterruptISR( void ) __attribute__((naked));
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/*
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* The tick interrupt handler.
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*/
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void vTickISR( void ) __attribute__((interrupt));
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/*-----------------------------------------------------------*/
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extern void *pxCurrentTCB;
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/*-----------------------------------------------------------*/
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/*
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* See header file for description.
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*/
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StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
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{
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/* R0 is not included as it is the stack pointer. */
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*pxTopOfStack = 0x00;
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pxTopOfStack--;
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*pxTopOfStack = portINITIAL_PSW;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) pxCode;
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/* When debugging it can be useful if every register is set to a known
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value. Otherwise code space can be saved by just setting the registers
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that need to be set. */
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#ifdef USE_FULL_REGISTER_INITIALISATION
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{
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pxTopOfStack--;
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*pxTopOfStack = 0xffffffff; /* r15. */
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pxTopOfStack--;
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*pxTopOfStack = 0xeeeeeeee;
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pxTopOfStack--;
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*pxTopOfStack = 0xdddddddd;
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pxTopOfStack--;
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*pxTopOfStack = 0xcccccccc;
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pxTopOfStack--;
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*pxTopOfStack = 0xbbbbbbbb;
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pxTopOfStack--;
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*pxTopOfStack = 0xaaaaaaaa;
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pxTopOfStack--;
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*pxTopOfStack = 0x99999999;
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pxTopOfStack--;
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*pxTopOfStack = 0x88888888;
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pxTopOfStack--;
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*pxTopOfStack = 0x77777777;
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pxTopOfStack--;
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*pxTopOfStack = 0x66666666;
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pxTopOfStack--;
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*pxTopOfStack = 0x55555555;
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pxTopOfStack--;
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*pxTopOfStack = 0x44444444;
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pxTopOfStack--;
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*pxTopOfStack = 0x33333333;
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pxTopOfStack--;
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*pxTopOfStack = 0x22222222;
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pxTopOfStack--;
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}
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#else
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{
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pxTopOfStack -= 15;
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}
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#endif
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*pxTopOfStack = ( StackType_t ) pvParameters; /* R1 */
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pxTopOfStack--;
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*pxTopOfStack = portINITIAL_FPSW;
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pxTopOfStack--;
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*pxTopOfStack = 0x12345678; /* Accumulator. */
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pxTopOfStack--;
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*pxTopOfStack = 0x87654321; /* Accumulator. */
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return pxTopOfStack;
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}
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/*-----------------------------------------------------------*/
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BaseType_t xPortStartScheduler( void )
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{
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extern void vApplicationSetupTimerInterrupt( void );
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/* Use pxCurrentTCB just so it does not get optimised away. */
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if( pxCurrentTCB != NULL )
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{
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/* Call an application function to set up the timer that will generate the
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tick interrupt. This way the application can decide which peripheral to
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use. A demo application is provided to show a suitable example. */
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vApplicationSetupTimerInterrupt();
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/* Enable the software interrupt. */
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_IEN( _ICU_SWINT ) = 1;
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/* Ensure the software interrupt is clear. */
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_IR( _ICU_SWINT ) = 0;
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/* Ensure the software interrupt is set to the kernel priority. */
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_IPR( _ICU_SWINT ) = configKERNEL_INTERRUPT_PRIORITY;
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/* Start the first task. */
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prvStartFirstTask();
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}
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/* Should not get here. */
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return pdFAIL;
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}
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/*-----------------------------------------------------------*/
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void vPortEndScheduler( void )
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{
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/* Not implemented in ports where there is nothing to return to.
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Artificially force an assert. */
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configASSERT( pxCurrentTCB == NULL );
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}
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/*-----------------------------------------------------------*/
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static void prvStartFirstTask( void )
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{
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__asm volatile
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(
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/* When starting the scheduler there is nothing that needs moving to the
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interrupt stack because the function is not called from an interrupt.
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Just ensure the current stack is the user stack. */
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"SETPSW U \n" \
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/* Obtain the location of the stack associated with which ever task
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pxCurrentTCB is currently pointing to. */
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"MOV.L #_pxCurrentTCB, R15 \n" \
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"MOV.L [R15], R15 \n" \
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"MOV.L [R15], R0 \n" \
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/* Restore the registers from the stack of the task pointed to by
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pxCurrentTCB. */
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"POP R15 \n" \
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/* Accumulator low 32 bits. */
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"MVTACLO R15 \n" \
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"POP R15 \n" \
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/* Accumulator high 32 bits. */
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"MVTACHI R15 \n" \
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"POP R15 \n" \
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/* Floating point status word. */
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"MVTC R15, FPSW \n" \
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/* R1 to R15 - R0 is not included as it is the SP. */
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"POPM R1-R15 \n" \
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/* This pops the remaining registers. */
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"RTE \n" \
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"NOP \n" \
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"NOP \n"
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);
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}
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/*-----------------------------------------------------------*/
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void vSoftwareInterruptISR( void )
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{
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__asm volatile
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(
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/* Re-enable interrupts. */
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"SETPSW I \n" \
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/* Move the data that was automatically pushed onto the interrupt stack when
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the interrupt occurred from the interrupt stack to the user stack.
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R15 is saved before it is clobbered. */
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"PUSH.L R15 \n" \
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/* Read the user stack pointer. */
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"MVFC USP, R15 \n" \
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/* Move the address down to the data being moved. */
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"SUB #12, R15 \n" \
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"MVTC R15, USP \n" \
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/* Copy the data across, R15, then PC, then PSW. */
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"MOV.L [ R0 ], [ R15 ] \n" \
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"MOV.L 4[ R0 ], 4[ R15 ] \n" \
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"MOV.L 8[ R0 ], 8[ R15 ] \n" \
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/* Move the interrupt stack pointer to its new correct position. */
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"ADD #12, R0 \n" \
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/* All the rest of the registers are saved directly to the user stack. */
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"SETPSW U \n" \
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/* Save the rest of the general registers (R15 has been saved already). */
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"PUSHM R1-R14 \n" \
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/* Save the FPSW and accumulator. */
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"MVFC FPSW, R15 \n" \
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"PUSH.L R15 \n" \
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"MVFACHI R15 \n" \
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"PUSH.L R15 \n" \
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/* Middle word. */
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"MVFACMI R15 \n" \
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/* Shifted left as it is restored to the low order word. */
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"SHLL #16, R15 \n" \
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"PUSH.L R15 \n" \
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/* Save the stack pointer to the TCB. */
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"MOV.L #_pxCurrentTCB, R15 \n" \
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"MOV.L [ R15 ], R15 \n" \
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"MOV.L R0, [ R15 ] \n" \
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/* Ensure the interrupt mask is set to the syscall priority while the kernel
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structures are being accessed. */
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"MVTIPL %0 \n" \
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/* Select the next task to run. */
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"BSR.A _vTaskSwitchContext \n" \
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/* Reset the interrupt mask as no more data structure access is required. */
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"MVTIPL %1 \n" \
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/* Load the stack pointer of the task that is now selected as the Running
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state task from its TCB. */
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"MOV.L #_pxCurrentTCB,R15 \n" \
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"MOV.L [ R15 ], R15 \n" \
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"MOV.L [ R15 ], R0 \n" \
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/* Restore the context of the new task. The PSW (Program Status Word) and
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PC will be popped by the RTE instruction. */
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"POP R15 \n" \
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"MVTACLO R15 \n" \
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"POP R15 \n" \
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"MVTACHI R15 \n" \
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"POP R15 \n" \
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"MVTC R15, FPSW \n" \
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"POPM R1-R15 \n" \
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"RTE \n" \
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"NOP \n" \
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"NOP "
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:: "i"(configMAX_SYSCALL_INTERRUPT_PRIORITY), "i"(configKERNEL_INTERRUPT_PRIORITY)
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);
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}
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/*-----------------------------------------------------------*/
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void vTickISR( void )
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{
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/* Re-enabled interrupts. */
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__asm volatile( "SETPSW I" );
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/* Increment the tick, and perform any processing the new tick value
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necessitates. Ensure IPL is at the max syscall value first. */
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portDISABLE_INTERRUPTS_FROM_KERNEL_ISR();
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{
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if( xTaskIncrementTick() != pdFALSE )
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{
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taskYIELD();
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}
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}
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portENABLE_INTERRUPTS_FROM_KERNEL_ISR();
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}
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/*-----------------------------------------------------------*/
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uint32_t ulPortGetIPL( void )
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{
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__asm volatile
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(
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"MVFC PSW, R1 \n" \
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"SHLR #24, R1 \n" \
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"RTS "
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);
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/* This will never get executed, but keeps the compiler from complaining. */
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return 0;
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}
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/*-----------------------------------------------------------*/
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void vPortSetIPL( uint32_t ulNewIPL )
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{
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__asm volatile
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(
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"PUSH R5 \n" \
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"MVFC PSW, R5 \n" \
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"SHLL #24, R1 \n" \
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"AND #-0F000001H, R5 \n" \
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"OR R1, R5 \n" \
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"MVTC R5, PSW \n" \
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"POP R5 \n" \
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"RTS "
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);
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}
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