149 lines
6.7 KiB
C
149 lines
6.7 KiB
C
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/*
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* FreeRTOS Kernel V10.0.0
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* Copyright (C) 2017 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. If you wish to use our Amazon
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* FreeRTOS name, please do so in a fair use way that does not cause confusion.
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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 ARM CM4F 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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/*
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* Start first task is a separate function so it can be tested in isolation.
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*/
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void vPortStartFirstTask( void ) __attribute__ (( naked ));
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/*
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* Exception handlers.
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*/
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void vPortSVCHandler( void ) __attribute__ (( naked ));
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void xPortPendSVHandler( void ) __attribute__ (( naked ));
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/*-----------------------------------------------------------*/
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void vPortStartFirstTask( void )
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{
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__asm volatile(
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#if defined(__SES_ARM)
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" ldr r0, =_vectors \n" /* Locate the stack using _vectors table. */
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#else
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" ldr r0, =__isr_vector \n" /* Locate the stack using __isr_vector table. */
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#endif
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" ldr r0, [r0] \n"
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" msr msp, r0 \n" /* Set the msp back to the start of the stack. */
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" cpsie i \n" /* Globally enable interrupts. */
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" cpsie f \n"
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" dsb \n"
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" isb \n"
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#ifdef SOFTDEVICE_PRESENT
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/* Block kernel interrupts only (PendSV) before calling SVC */
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" mov r0, %0 \n"
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" msr basepri, r0 \n"
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#endif
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" svc 0 \n" /* System call to start first task. */
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" \n"
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" .align 2 \n"
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#ifdef SOFTDEVICE_PRESENT
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::"i"(configKERNEL_INTERRUPT_PRIORITY << (8 - configPRIO_BITS))
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#endif
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);
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}
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/*-----------------------------------------------------------*/
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void vPortSVCHandler( void )
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{
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__asm volatile (
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" ldr r3, =pxCurrentTCB \n" /* Restore the context. */
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" ldr r1, [r3] \n" /* Use pxCurrentTCBConst to get the pxCurrentTCB address. */
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" ldr r0, [r1] \n" /* The first item in pxCurrentTCB is the task top of stack. */
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" ldmia r0!, {r4-r11, r14} \n" /* Pop the registers that are not automatically saved on exception entry and the critical nesting count. */
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" msr psp, r0 \n" /* Restore the task stack pointer. */
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" isb \n"
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" mov r0, #0 \n"
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" msr basepri, r0 \n"
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" bx r14 \n"
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" \n"
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" .align 2 \n"
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);
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}
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/*-----------------------------------------------------------*/
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void xPortPendSVHandler( void )
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{
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/* This is a naked function. */
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__asm volatile
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(
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" mrs r0, psp \n"
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" isb \n"
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" \n"
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" ldr r3, =pxCurrentTCB \n" /* Get the location of the current TCB. */
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" ldr r2, [r3] \n"
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" \n"
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" tst r14, #0x10 \n" /* Is the task using the FPU context? If so, push high vfp registers. */
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" it eq \n"
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" vstmdbeq r0!, {s16-s31} \n"
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" \n"
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" stmdb r0!, {r4-r11, r14} \n" /* Save the core registers. */
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" \n"
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" str r0, [r2] \n" /* Save the new top of stack into the first member of the TCB. */
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" \n"
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" stmdb sp!, {r3} \n"
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" mov r0, %0 \n"
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" msr basepri, r0 \n"
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" dsb \n"
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" isb \n"
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" bl vTaskSwitchContext \n"
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" mov r0, #0 \n"
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" msr basepri, r0 \n"
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" ldmia sp!, {r3} \n"
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" \n"
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" ldr r1, [r3] \n" /* The first item in pxCurrentTCB is the task top of stack. */
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" ldr r0, [r1] \n"
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" \n"
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" ldmia r0!, {r4-r11, r14} \n" /* Pop the core registers. */
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" \n"
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" tst r14, #0x10 \n" /* Is the task using the FPU context? If so, pop the high vfp registers too. */
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" it eq \n"
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" vldmiaeq r0!, {s16-s31} \n"
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" \n"
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" msr psp, r0 \n"
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" isb \n"
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" \n"
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" \n"
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" bx r14 \n"
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" \n"
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" .align 2 \n"
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::"i"(configMAX_SYSCALL_INTERRUPT_PRIORITY << (8 - configPRIO_BITS))
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);
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}
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