将FreeRTOS实时操作系统内核移植到MM32F5270开发板上运行

FreeRTOS是一个在单片机上使用很广泛的实时操作系统内核，是一个轻量级的系统，功能包括：任务管理、时间管理、信号量、消息队列、内存管理、记录功能、软件定时器、协程等。

FreeRTOS操作系统是完全免费的操作系统，具有源码公开、可移植、可裁减、调度策略灵活的特点，可以方便地移植到各种单片机上运行。

MM32F5270功能比较多，芯片的性能也足够RTOS运行，一些比较大的项目，使用RTOS是事倍功半的。

首先，下载源码

这里使用的版本是FreeRTOS LTS 202012.04，这是一个长期支持版本，而且比较新，支持Armv8-M 架构。

由于MM32F5270芯片是Armv8-M 架构的，FreeRTOS也没有针对Arm China STAR-MC1的支持，从芯片的说明上，应该是没有TrustZone的。

所以，要使用的平台相关的文件，在FreeRTOS\FreeRTOS-Kernel\portable\ARMv8M中。

其中，portasm.c文件使用FreeRTOSv202012.04-LTS\FreeRTOS\FreeRTOS-Kernel\portable\ARMv8M\non_secure\portable\GCC\ARM_CM33_NTZ\non_secure中的相关文件。

工程目录下新建一个FreeRTOS的文件夹，把FreeRTOSv202012.04-LTS\FreeRTOS\FreeRTOS-Kernel中的文件复制到工程目录下。

在keil中添加相应的源文件，如下：

添加头文件路径：

默认是没有FreeRTOSConfig.h的，要手动进行添加。

/*
 * FreeRTOS Kernel V10.4.0
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * http://aws.amazon.com/freertos
 * http://www.FreeRTOS.org
 */

#ifndef FREERTOS_CONFIG_H
#define FREERTOS_CONFIG_H

#define configENABLE_FPU    0
#define configENABLE_MPU 0
#define configENABLE_TRUSTZONE 0

#define INCLUDE_vTaskDelayUntil                 1

#define configMAX_PRIORITIES                       ( 7 )
#define configUSE_PREEMPTION                       1
#define configMINIMAL_STACK_SIZE                   ( ( unsigned short ) 60 ) 
    #define configUSE_IDLE_HOOK                0
#ifndef configUSE_TICK_HOOK
    #define configUSE_TICK_HOOK            0
#endif
#define configUSE_16_BIT_TICKS                     0
#define configTICK_RATE_HZ                         ( 1000 )  
#define configCPU_CLOCK_HZ                 (120000000)                        
#define configMAX_SYSCALL_INTERRUPT_PRIORITY        191
#define configTOTAL_HEAP_SIZE                      ( ( size_t ) ( 2* 1024U ) )
#define INCLUDE_xTaskGetCurrentTaskHandle 1


#define xPortSysTickHandler SysTick_Handler
#define xPortPendSVHandler    PendSV_Handler
#define vPortSVCHandler SVC_Handler

#endif /* FREERTOS_CONFIG_H */

在main函数中，增加一个任务

bool led=false;
void vTaskLED(void * pvParameters)
{ 
    portTickType xLastWakeTime; 
    
    xLastWakeTime = xTaskGetTickCount(); 
    while(1)
    {
        led=!led;
        GPIO_WriteBit(BOARD_LED0_GPIO_PORT, BOARD_LED0_GPIO_PIN, led);
        xTaskDelayUntil( &xLastWakeTime, ( 250 / portTICK_RATE_MS ) ); 
  }
}

并在main函数中创建这个任务

int main(void)
{
    BOARD_Init();

    printf("\r\ngpio_basic example.\r\n");
    xTaskCreate(vTaskLED, "LED", 128, NULL, 3, NULL);
    vTaskStartScheduler();
    while (1)
    {
        if ( GPIO_ReadInDataBit(BOARD_KEY0_GPIO_PORT, BOARD_KEY0_GPIO_PIN) ) /* key is no pressed. */
        {
            GPIO_WriteBit(BOARD_LED0_GPIO_PORT, BOARD_LED0_GPIO_PIN, 1u); /* led off. */
            GPIO_WriteBit(BOARD_LED1_GPIO_PORT, BOARD_LED1_GPIO_PIN, 0u); /* led on. */
        }
        else /* key is pressed. */
        {
            GPIO_WriteBit(BOARD_LED0_GPIO_PORT, BOARD_LED0_GPIO_PIN, 0u); /* led on. */
            GPIO_WriteBit(BOARD_LED1_GPIO_PORT, BOARD_LED1_GPIO_PIN, 1u); /* led off. */
        }
    }
}

完成看，开始编译，编译没有错误。

原作者：ifconfig