用c语言写一个bootloader上位机

由于问题不清晰，我不知道您所需的功能和具体要求。以下是一个简单的bootloader上位机，可以通过串口与bootloader通信，实现读/写Flash、跳转到应用程序等基本功能。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>

#define BUF_SIZE 1024

int serial_fd;

int open_serial(const char *dev_name, int baud_rate) {
    int fd = open(dev_name, O_RDWR | O_NOCTTY | O_NDELAY);
    if (fd < 0) {
        perror("open_serial");
        return -1;
    }

    struct termios options;
    tcgetattr(fd, &options);
    cfmakeraw(&options);

    options.c_cflag |= (CLOCAL | CREAD);
    options.c_cflag &= ~PARENB;
    options.c_cflag &= ~CSTOPB;
    options.c_cflag &= ~CSIZE;
    options.c_cflag |= CS8;

    cfsetispeed(&options, baud_rate);
    cfsetospeed(&options, baud_rate);

    options.c_cc[VTIME] = 0;
    options.c_cc[VMIN] = 1;

    tcsetattr(fd, TCSANOW, &options);

    return fd;
}

int send_cmd(const char *cmd) {
    return write(serial_fd, cmd, strlen(cmd));
}

int read_resp(char *buf, size_t size) {
    int n = read(serial_fd, buf, size - 1);
    if (n < 0) {
        perror("read_resp");
        return -1;
    }
    buf[n] = '\0';
    return n;
}

int send_recv(const char *cmd, char *buf, size_t size) {
    if (send_cmd(cmd) < 0) {
        return -1;
    }
    usleep(100000);
    return read_resp(buf, size);
}

int read_flash(int addr, char *buf, size_t size) {
    char cmd[BUF_SIZE];
    snprintf(cmd, BUF_SIZE, "R %08X %d\n", addr, size);
    return send_recv(cmd, buf, size);
}

int write_flash(int addr, const char *buf, size_t size) {
    char cmd[BUF_SIZE];
    snprintf(cmd, BUF_SIZE, "W %08X %d\n", addr, size);
    if (send_cmd(cmd) < 0) {
        return -1;
    }
    usleep(100000);
    if (write(serial_fd, buf, size) < 0) {
        perror("write_flash");
        return -1;
    }
    char resp[BUF_SIZE];
    if (read_resp(resp, BUF_SIZE) < 0) {
        return -1;
    }
    if (strcmp(resp, "OK\n") != 0) {
        return -1;
    }
    return size;
}

int jmp_app() {
    return send_cmd("J\n");
}

int main(int argc, char *argv[]) {
    if (argc != 3) {
        printf("Usage: %s dev_name baud_rate\n", argv[0]);
        return -1;
    }

    const char *dev_name = argv[1];
    int baud_rate = atoi(argv[2]);
    serial_fd = open_serial(dev_name, baud_rate);
    if (serial_fd < 0) {
        return -1;
    }

    char buf[BUF_SIZE];

    // 读取Flash
    int addr = 0x08000000;
    int size = 16;
    if (read_flash(addr, buf, size) < 0) {
        return -1;
    }
    for (int i = 0; i < size; i++) {
        printf("%02X ", (unsigned char)buf[i]);
    }
    printf("\n");

    // 写入Flash
    char data[] = {0x12, 0x34, 0x56, 0x78};
    size = sizeof(data);
    if (write_flash(addr, data, size) < 0) {
        return -1;
    }

    // 跳转到应用程序
    if (jmp_app() < 0) {
        return -1;
    }

    close(serial_fd);
    return 0;
}

该程序可以通过命令行参数指定串口设备名称和波特率，读取Flash、写入Flash和跳转到应用程序等操作分别对应read_flash()、write_flash()和jmp_app()函数。由于bootloader上位机的具体实现可能与硬件和操作系统相关，所以该程序可能需要进行修改才能在您的环境中正常运行。