打印
[STM32F1]

【转】STM32的Bootloader详解

[复制链接]
7235|1
手机看帖
扫描二维码
随时随地手机跟帖
跳转到指定楼层
楼主
说书先生|  楼主 | 2016-12-25 12:47 | 只看该作者 回帖奖励 |倒序浏览 |阅读模式

一、           实验目的和要求

1.     理解uboot等bootloader的一般功能和基本工作原理;

2.     掌握在STM32F上编写逻辑程序并下载运行的方法。


二、           实验器材

1.     STM32F103核心板一块;

2.     MicroUSB线一根;

3.     STLink板或USB串口板一块;

4.     交叉编译软件


三、           实验内容和原理

1.写一个自己的简易bootloader,能通过串口执行两条最简单的指令

a)       Peek addr以一个字为单位读取内存中addr位置的数据(addr是4字节对齐,十六进制的形式,长度为8位十六进制,例如0x00008000),并以十六进制的形式输出;

b)       Poke addr data以一个字为单位修改内存中addr位置的数据为data(addr是4字节对齐,十六进制的形式,长度为8位十六进制,data也是十六进制的形式,长度为8位十六进制)


四、           实验过程和数据记录

1.     下面是实物连接图.ST-LINK与STM32开发板的连接如下



2.     设置PA9为TX,PA10为RX,并且配置串口参数,波特率为9600,8n1





3.     设置后生成代码,设置为MDK-ARM V5项目,并且打开Keli MDK,修改其中main.c函数内容。

4.     实现的bootloader代码如下,主要实现其两个功能,分别为peek和poke功能。


沙发
说书先生|  楼主 | 2016-12-25 12:48 | 只看该作者
以下是修改之后main.c的代码
/**
  ******************************************************************************
  * File Name          : main.c
  * Description        : Main program body
  ******************************************************************************
  *
  * COPYRIGHT(c) 2016 STMicroelectronics
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *   1. Redistributions of source code must retain the above copyright notice,
  *      this list of conditions and the following disclaimer.
  *   2. Redistributions in binary form must reproduce the above copyright notice,
  *      this list of conditions and the following disclaimer in the documentation
  *      and/or other materials provided with the distribution.
  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
  *      without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  */
/* Includes ------------------------------------------------------------------*/
#include "stm32f1xx_hal.h"

/* USER CODE BEGIN Includes */
#include <string.h>

/* USER CODE END Includes */

/* Private variables ---------------------------------------------------------*/
UART_HandleTypeDef huart1;

/* USER CODE BEGIN PV */
/* Private variables ---------------------------------------------------------*/
int UserAppStarting = 0x08003000;

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART1_UART_Init(void);

/* USER CODE BEGIN PFP */
/* Private function prototypes -----------------------------------------------*/

/* USER CODE END PFP */

/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

int main(void)
{

  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration----------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* Configure the system clock */
  SystemClock_Config();

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_USART1_UART_Init();

  /* USER CODE BEGIN 2 */
       uint32_t test = 0x33333333;

       char uchar[10] = {0};
       uint32_t addr, data;

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
       printf("This is Bootloader!\r\n");
       printf("addr: 0x%08x\r\nval: 0x%08x\r\n", &test, test);
  while (1)
  {
  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */
              printf("Command(peek or poke):\r\n");
              scanf("%s", uchar);
              scanf("%x", &addr);

              if (strcmp(uchar, "peek") == 0)
              {
                     printf("Data at 0x%08x: 0x%08x\r\n", addr, *((uint32_t *)addr));
              }
              else if (strcmp(uchar, "poke") == 0)
              {
                     printf("Data is:\r\n");
                     scanf("%x", &data);
                     *((uint32_t *)addr) = data;
                     printf("Change in 0x%08x: 0x%08x\r\n", addr, data);
              }
  }
  /* USER CODE END 3 */

}

/** System Clock Configuration
*/
void SystemClock_Config(void)
{

  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = 16;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  HAL_RCC_OscConfig(&RCC_OscInitStruct);

  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0);

  HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);

  HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);

  /* SysTick_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
}

/* USART1 init function */
void MX_USART1_UART_Init(void)
{

  huart1.Instance = USART1;
  huart1.Init.BaudRate = 9600;
  huart1.Init.WordLength = UART_WORDLENGTH_8B;
  huart1.Init.StopBits = UART_STOPBITS_1;
  huart1.Init.Parity = UART_PARITY_NONE;
  huart1.Init.Mode = UART_MODE_TX_RX;
  huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart1.Init.OverSampling = UART_OVERSAMPLING_16;
  HAL_UART_Init(&huart1);

}

/** Pinout Configuration
*/
void MX_GPIO_Init(void)
{

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOA_CLK_ENABLE();

}

/* USER CODE BEGIN 4 */
int fputc(int ch, FILE *f)
{
  /* Place your implementation of fputc here */
  /* e.g. write a character to the USART1 and Loop until the end of transmission */
  HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);

  return ch;
}
int fgetc(FILE *f)
{
       uint8_t ch;
       HAL_UART_Receive(&huart1, (uint8_t *)&ch, 1, 0xFFFF);
       if (ch == 0x0d)
       {
              fputc(0x0d, f);
              fputc(0x0a, f);
       }
       else
       {
              fputc(ch, f);
       }

       return ch;
}

/* USER CODE END 4 */

#ifdef USE_FULL_ASSERT

/**
   * @brief Reports the name of the source file and the source line number
   * where the assert_param error has occurred.
   * @param file: pointer to the source file name
   * @param line: assert_param error line source number
   * @retval None
   */
void assert_failed(uint8_t* file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
    ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */

}

#endif

/**
  * @}
  */

/**
  * @}
*/

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

5.     实验操作结果如下:



首先使用peek查看地址为2000044c的数据,为0x33333333(初始设置值,在代码中可以看到),之后通过poke修改为0x11111111,再通过peek看是否修改成功。由图可知实验顺利输出修改后的值。

使用特权

评论回复
发新帖 我要提问
您需要登录后才可以回帖 登录 | 注册

本版积分规则

71

主题

191

帖子

0

粉丝