导言
本章节做一个实验“校验一遍App缓存区的固件”,看看能不能通过CRC32校验。在OTA升级流程上,当bootloader程序接收完上位机下发的App固件到App下载缓存区后,bootloader程序要对App下载缓存区的固件进行CRC32校验。
- 校验通过的话,将App下载区的固件Copy到App区,Copy完成后,跳转至App运行即可完成OTA升级。
- 校验失败的话,bootloader程序将反馈“OTA升级失败”给上位机。然后,跳转至App运行。等待下一次OTA升级的请求。
项目地址:
github: https://github.com/q164129345/MCU_Develop/tree/main/bootloader07_stm32f103_check_crc32
gitee(国内): https://gitee.com/wallace89/MCU_Develop/tree/main/bootloader07_stm32f103_check_crc32
一、将App_crc.bin下载到App下载缓存区
项目当前还没有开发跟上位机的通讯,为了验证“对App下载缓存区的固件进行CRC32的校验“。可以先使用下载器(J-LINK或者ST-LINK)将固件下载到App缓存区。
1.1、J-Flash将App_crc.bin下载到App下载缓存区
1.2、Keil的debug模式,Viewer->Memory2核对固件内容
二、bootloader程序代码
2.1、soft_crc32.c
#include "soft_crc32.h"
#include <string.h>
#include <stdint.h>/*** @brief CRC32 查找表(多项式:0xEDB88320,反转算法)* @note * - 表中共256项,对应每一个可能的字节值;* - 用于快速查表计算,提高CRC32效率;* - 本表使用标准以太网CRC32多项式(即:IEEE 802.3)生成;* - 生成公式:多项式为 0x04C11DB7,反转为 0xEDB88320。*/
static const uint32_t crc32_tab[256] = {0x00000000u, 0x77073096u, 0xEE0E612Cu, 0x990951BAu, 0x076DC419u, 0x706AF48Fu,0xE963A535u, 0x9E6495A3u, 0x0EDB8832u, 0x79DCB8A4u, 0xE0D5E91Eu, 0x97D2D988u,0x09B64C2Bu, 0x7EB17CBDu, 0xE7B82D07u, 0x90BF1D91u, 0x1DB71064u, 0x6AB020F2u,0xF3B97148u, 0x84BE41DEu, 0x1ADAD47Du, 0x6DDDE4EBu, 0xF4D4B551u, 0x83D385C7u,0x136C9856u, 0x646BA8C0u, 0xFD62F97Au, 0x8A65C9ECu, 0x14015C4Fu, 0x63066CD9u,0xFA0F3D63u, 0x8D080DF5u, 0x3B6E20C8u, 0x4C69105Eu, 0xD56041E4u, 0xA2677172u,0x3C03E4D1u, 0x4B04D447u, 0xD20D85FDu, 0xA50AB56Bu, 0x35B5A8FAu, 0x42B2986Cu,0xDBBBC9D6u, 0xACBCF940u, 0x32D86CE3u, 0x45DF5C75u, 0xDCD60DCFu, 0xABD13D59u,0x26D930ACu, 0x51DE003Au, 0xC8D75180u, 0xBFD06116u, 0x21B4F4B5u, 0x56B3C423u,0xCFBA9599u, 0xB8BDA50Fu, 0x2802B89Eu, 0x5F058808u, 0xC60CD9B2u, 0xB10BE924u,0x2F6F7C87u, 0x58684C11u, 0xC1611DABu, 0xB6662D3Du, 0x76DC4190u, 0x01DB7106u,0x98D220BCu, 0xEFD5102Au, 0x71B18589u, 0x06B6B51Fu, 0x9FBFE4A5u, 0xE8B8D433u,0x7807C9A2u, 0x0F00F934u, 0x9609A88Eu, 0xE10E9818u, 0x7F6A0DBBu, 0x086D3D2Du,0x91646C97u, 0xE6635C01u, 0x6B6B51F4u, 0x1C6C6162u, 0x856530D8u, 0xF262004Eu,0x6C0695EDu, 0x1B01A57Bu, 0x8208F4C1u, 0xF50FC457u, 0x65B0D9C6u, 0x12B7E950u,0x8BBEB8EAu, 0xFCB9887Cu, 0x62DD1DDFu, 0x15DA2D49u, 0x8CD37CF3u, 0xFBD44C65u,0x4DB26158u, 0x3AB551CEu, 0xA3BC0074u, 0xD4BB30E2u, 0x4ADFA541u, 0x3DD895D7u,0xA4D1C46Du, 0xD3D6F4FBu, 0x4369E96Au, 0x346ED9FCu, 0xAD678846u, 0xDA60B8D0u,0x44042D73u, 0x33031DE5u, 0xAA0A4C5Fu, 0xDD0D7CC9u, 0x5005713Cu, 0x270241AAu,0xBE0B1010u, 0xC90C2086u, 0x5768B525u, 0x206F85B3u, 0xB966D409u, 0xCE61E49Fu,0x5EDEF90Eu, 0x29D9C998u, 0xB0D09822u, 0xC7D7A8B4u, 0x59B33D17u, 0x2EB40D81u,0xB7BD5C3Bu, 0xC0BA6CADu, 0xEDB88320u, 0x9ABFB3B6u, 0x03B6E20Cu, 0x74B1D29Au,0xEAD54739u, 0x9DD277AFu, 0x04DB2615u, 0x73DC1683u, 0xE3630B12u, 0x94643B84u,0x0D6D6A3Eu, 0x7A6A5AA8u, 0xE40ECF0Bu, 0x9309FF9Du, 0x0A00AE27u, 0x7D079EB1u,0xF00F9344u, 0x8708A3D2u, 0x1E01F268u, 0x6906C2FEu, 0xF762575Du, 0x806567CBu,0x196C3671u, 0x6E6B06E7u, 0xFED41B76u, 0x89D32BE0u, 0x10DA7A5Au, 0x67DD4ACCu,0xF9B9DF6Fu, 0x8EBEEFF9u, 0x17B7BE43u, 0x60B08ED5u, 0xD6D6A3E8u, 0xA1D1937Eu,0x38D8C2C4u, 0x4FDFF252u, 0xD1BB67F1u, 0xA6BC5767u, 0x3FB506DDu, 0x48B2364Bu,0xD80D2BDAu, 0xAF0A1B4Cu, 0x36034AF6u, 0x41047A60u, 0xDF60EFC3u, 0xA867DF55u,0x316E8EEFu, 0x4669BE79u, 0xCB61B38Cu, 0xBC66831Au, 0x256FD2A0u, 0x5268E236u,0xCC0C7795u, 0xBB0B4703u, 0x220216B9u, 0x5505262Fu, 0xC5BA3BBEu, 0xB2BD0B28u,0x2BB45A92u, 0x5CB36A04u, 0xC2D7FFA7u, 0xB5D0CF31u, 0x2CD99E8Bu, 0x5BDEAE1Du,0x9B64C2B0u, 0xEC63F226u, 0x756AA39Cu, 0x026D930Au, 0x9C0906A9u, 0xEB0E363Fu,0x72076785u, 0x05005713u, 0x95BF4A82u, 0xE2B87A14u, 0x7BB12BAEu, 0x0CB61B38u,0x92D28E9Bu, 0xE5D5BE0Du, 0x7CDCEFB7u, 0x0BDBDF21u, 0x86D3D2D4u, 0xF1D4E242u,0x68DDB3F8u, 0x1FDA836Eu, 0x81BE16CDu, 0xF6B9265Bu, 0x6FB077E1u, 0x18B74777u,0x88085AE6u, 0xFF0F6A70u, 0x66063BCAu, 0x11010B5Cu, 0x8F659EFFu, 0xF862AE69u,0x616BFFD3u, 0x166CCF45u, 0xA00AE278u, 0xD70DD2EEu, 0x4E048354u, 0x3903B3C2u,0xA7672661u, 0xD06016F7u, 0x4969474Du, 0x3E6E77DBu, 0xAED16A4Au, 0xD9D65ADCu,0x40DF0B66u, 0x37D83BF0u, 0xA9BCAE53u, 0xDEBB9EC5u, 0x47B2CF7Fu, 0x30B5FFE9u,0xBDBDF21Cu, 0xCABAC28Au, 0x53B39330u, 0x24B4A3A6u, 0xBAD03605u, 0xCDD70693u,0x54DE5729u, 0x23D967BFu, 0xB3667A2Eu, 0xC4614AB8u, 0x5D681B02u, 0x2A6F2B94u,0xB40BBE37u, 0xC30C8EA1u, 0x5A05DF1Bu, 0x2D02EF8Du
};/*** @brief CRC32 数据块更新函数(软件实现)* @param crc 当前CRC值(可为上一次中间结果)* @param buf 指向待处理数据缓冲区* @param len 数据长度(单位:字节)* @retval 更新后的CRC32值* @note * - 基于查表法实现,效率较高;* - 可用于分块计算、流式处理;* - 该函数不进行补码处理(XOR输出需外部完成)。*/
uint32_t CRC32_Update(uint32_t crc, const void *buf, uint32_t len)
{const uint8_t *p = (const uint8_t *)buf;while (len--)crc = crc32_tab[(crc ^ *p++) & 0xFFu] ^ (crc >> 8);return crc;
}/*** @brief 计算Flash中固件数据的CRC32值(软件方式)* @param flash_addr Flash起始地址(通常为固件起始地址)* @param total_len 固件总长度(注意!!不包含最后的CRC32校验码)* @retval 计算出的CRC32值(已完成反码)* @note * - 本函数用于Bootloader自检或烧录验证;* - 默认按块处理(每块256字节),支持未来DMA/多段扩展;* - 初始值为0xFFFFFFFF,最终异或输出结果。*/
uint32_t Calculate_Firmware_CRC32_SW(uint32_t flash_addr, uint32_t total_len)
{uint32_t crc = 0xFFFFFFFFu;const uint8_t *p = (const uint8_t *)flash_addr;/* 按 256 B 块处理,可边走边校验;此处简单循环 */while (total_len){uint32_t chunk = (total_len > 256u) ? 256u : total_len;crc = CRC32_Update(crc, p, chunk);p += chunk;total_len -= chunk;}return crc ^ 0xFFFFFFFFu;
}
2.2、soft_crc32.h
/*** @file soft_crc32.h* @brief 纯软件 CRC-32/ISO-HDLC 计算(RefIn/RefOut = 1)* @author Wallace* @date 2025-05-29* @version 1.0.0*/#ifndef __SOFT_CRC32_H
#define __SOFT_CRC32_H#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif/*** @brief 初始化 CRC 上下文* @return 初始值 0xFFFF?FFFF*/
static inline uint32_t CRC32_Init(void) { return 0xFFFFFFFFu; }/*** @brief 输入若干字节并更新 CRC*/
uint32_t CRC32_Update(uint32_t crc, const void *buf, uint32_t len);/*** @brief 计算完成后取反得到最终 CRC*/
static inline uint32_t CRC32_Final(uint32_t crc) { return crc ^ 0xFFFFFFFFu; }/*** @brief 便捷接口:一次性计算整个缓冲区*/
static inline uint32_t CRC32_Calc(const void *buf, uint32_t len)
{return CRC32_Final(CRC32_Update(CRC32_Init(), buf, len));
}/*** @brief 计算Flash中固件数据的CRC32值(软件方式)*/
uint32_t Calculate_Firmware_CRC32_SW(uint32_t flash_addr, uint32_t total_len);#ifdef __cplusplus
}
#endif
#endif /* __SOFT_CRC32_H */
2.3、main.c
三、测试代码
CRC32校验通过,App下载区的固件完整性没有问题。