哪位大佬知道update.img的头部信息如何修改

Chip Platform Rockchip
1 
//解析固件，获得固件头部信息
int analyticImage(const char *filepath, PRKIMAGE_HDR phdr) {
    long long ulFwSize;
    STRUCT_RKIMAGE_HEAD rkimage_head;
    unsigned char m_md5[32];

    int fd = open(filepath, O_RDONLY);
    if (fd < 0) {
        LOGE("Can't open %s\n", filepath);
        return -2;
    }

    //1. image 头部信息读取
    if (read(fd, &rkimage_head, sizeof(STRUCT_RKIMAGE_HEAD)) != sizeof(STRUCT_RKIMAGE_HEAD)) {
        LOGE("Can't read %s\n(%s)\n", filepath, strerror(errno));
        close(fd);
        return -2;
    }

    if ((rkimage_head.reserved[14]=='H')&&(rkimage_head.reserved[15]=='I')) {
        ulFwSize = *((DWORD *)(&rkimage_head.reserved[16]));
        ulFwSize <<= 32;
        ulFwSize += rkimage_head.dwFWOffset;
        ulFwSize += rkimage_head.dwFWSize;
    } else {
        ulFwSize = rkimage_head.dwFWOffset + rkimage_head.dwFWSize;
    }
    rkimage_head.dwFWSize = ulFwSize - rkimage_head.dwFWOffset;
    display_head(&rkimage_head);

    //2. 固件md5 校验
    long long fileSize;
    int nMd5DataSize;

    fileSize = lseek64(fd, 0L, SEEK_END);
    nMd5DataSize = fileSize - ulFwSize;
    if (nMd5DataSize >= 160) {
        LOGE("md5 : not support sign image.\n");
        //sign image
        //m_bSignFlag = true;
        //m_signMd5Size = nMd5DataSize-32;
        //fseeko64(m_pFile,ulFwSize,SEEK_SET);
        //fread(m_md5,1,32,m_pFile);
        //fread(m_signMd5,1,nMd5DataSize-32,m_pFile);
    } else {
        lseek64(fd, -32, SEEK_END);
        if ( read(fd, m_md5, 32) != 32) {
            LOGE("lseek failed.\n");
            return -2;
        }
    }

    //3. image 地址信息读取
    if (lseek64(fd, rkimage_head.dwFWOffset, SEEK_SET) == -1) {
        LOGE("lseek failed.\n");
        return -2;
    }

    if (read(fd, phdr, sizeof(RKIMAGE_HDR)) != sizeof(RKIMAGE_HDR)) {
        LOGE("Can't read %s\n(%s)\n", filepath, strerror(errno));
        close(fd);
        return -2;
    }

    if (phdr->tag != RKIMAGE_TAG) {
        LOGE("tag: %x\n", phdr->tag);
        LOGE("Invalid image\n");
        return -3;
    }

    if (rkimage_head.dwFWOffset) {
        adjustFileOffset(phdr, rkimage_head.dwFWOffset, rkimage_head.dwBootOffset, rkimage_head.dwBootSize);
    }

    display_hdr(phdr);

    close(fd);
    #if 1
    if (!compareMd5sum((char*)filepath, m_md5, 0, fileSize-32)) {
        LOGE("Md5Check update.img fwSize:%ld", fileSize-32);
        return -1;
    }
    #endif
    LOGI("analyticImage ok.\n");
    return 0;
}