一.前言
前面我们移植了FATFS文件系统，此时就可以方便地读取TF卡上的文件了。为了和开发板进行交互，我们继续实现通过xmodem导入导出文件的功能。xmodem的实现和shell的实现参考公众号文章。
https://mp.weixin.qq.com/s/QSYKxND3DTyQZ0JtnSqkzQ XMODEM协议介绍与高效高可移植非阻塞版本实现
https://mp.weixin.qq.com/s/XLmbJn0SKoDT1aLdxHDrbg一个超级精简高可移植的shell命令行C实现
二.Xmodem导入文件
shell_func.c中
添加fatfs头文件
#include "ff.h"
中申明实现函数
static void rxfilefunc(uint8_t* param);
g_shell_cmd_list_ast中添加一行
{ (uint8_t*)"rxfile", rxfilefunc, (uint8_t*)"rxfile name len"},
实现函数rxfilefunc
void rxfilefunc(uint8_t* param){char name[64];uint32_t len;int res = 0;if(2 == sscanf((const char*)param, "%*s %s %ld", name, &len)){xprintf("rxfile %s %ld\r\n",name,len);if(0 == rx_file_open(name)){xmodem_cfg_st cfg={.buffer = rxtx_buf,.crccheck = 1,.getms = getms,.io_read = io_read,.io_read_flush = io_read_flush,.io_write = io_write,.start_timeout = 60,.packet_timeout = 1000,.ack_timeout = 1000,.mem_write = rx_file_write,.addr = 0,.totallen = len,};xmodem_init_rx(&cfg);while((res = xmodem_rx()) == 0);rx_file_close(name);xprintf("res:%d\r\n",res);}else{xprintf("open:%s err\r\n",name);}}}
需要实现相关的接口
static uint8_t rxtx_buf[1029];static uint32_t getms(void){return os_boot_time32();}static uint32_t io_read(uint8_t* buffer, uint32_t len){return fifo_cdc_rx_read(buffer, len);}static void io_read_flush(void){uint8_t tmp;while(0 != fifo_cdc_rx_read(&tmp, 1));}static uint32_t io_write(uint8_t* buffer, uint32_t len){fifo_cdc_tx_write(buffer, len);return len;}
文件相关接口
static FIL rx_fil; /* File object */static int rx_file_open_flag = 0;static int rx_file_open(char* name){FRESULT res = f_open(&rx_fil, name, FA_CREATE_NEW | FA_WRITE);if (FR_OK == 0){rx_file_open_flag = 1;return 0;}else{xprintf("open %s err %d\r\n",name,res);return -1;}}static int rx_file_close(char* name){if(rx_file_open_flag != 0){rx_file_open_flag = 0;FRESULT res = f_close(&rx_fil);if(res != FR_OK){xprintf("close err %d\r\n",res);}return 0;}else{return -1;}}static uint32_t rx_file_write(uint32_t addr, uint8_t* buffer, uint32_t len){if(rx_file_open_flag != 0){UINT bw;FRESULT res = f_write(&rx_fil, buffer, len, &bw);if ((bw != len) || (res != FR_OK)){xprintf("write err %d %d\r\n",bw,res);}return bw;}else{return 0;}}
需要初始化时已经挂在文件系统
static FATFS fs; /* Filesystem object */if(0 == (r = sd_itf_init())){if(FR_OK != (res = f_mount (&fs, "0:", 1))){printf("mount err %d, mkfs\r\n",res);res = f_mkfs("0:",0,work,sizeof(work));if(res == 0){printf("mkfs ok\r\n");if(FR_OK == f_mount (&fs, "0:", 1)){printf("mount ok\r\n");}else{printf("mount err\r\n");}}else{printf("mkfs err %d\r\n",res);}}else{printf("mount ok\r\n");} }else{printf("sd init err:%d\r\n",r);}
测试输入help查看新添加的命令
输入
rxfile zhcy093.pdf 2573119回车
Crt中菜单栏
Transfer->Send Xmodem...
选择对应的文件，打开开始发送
开始传输
传输完成
用读卡器查看导入的文件
计算校验信息和原始文件一样
三. Xmodem导出文件
shell_func.c中
中申明实现函数
static void sxfilefunc(uint8_t* param);
g_shell_cmd_list_ast中添加一行
{ (uint8_t*)"sxfile", sxfilefunc, (uint8_t*)"sxfile name len"},
实现函数sxfilefunc
void sxfilefunc(uint8_t* param){char name[64];uint32_t len;int res = 0;if(2 == sscanf((const char*)param, "%*s %s %ld", name, &len)){xprintf("sxfile %s %ld\r\n",name,len);if(0 == tx_file_open(name)){xmodem_cfg_st cfg={.buffer = rxtx_buf,.plen = 1024,.getms = getms,.io_read = io_read,.io_read_flush = io_read_flush,.io_write = io_write,.start_timeout = 60,.packet_timeout = 1000,.ack_timeout = 5000,.mem_read = tx_file_read,.addr = 0,.totallen = len,};xmodem_init_tx(&cfg);while((res = xmodem_tx()) == 0);tx_file_close(name);xprintf("res:%d\r\n",res);}else{xprintf("open:%s err\r\n",name);}}}
文件读接口实现
static FIL tx_fil; /* File object */static int tx_file_open_flag = 0;static int tx_file_open(char* name){FRESULT res = f_open(&tx_fil, name, FA_READ);if (FR_OK == 0){tx_file_open_flag = 1;return 0;}else{xprintf("open %s err %d\r\n",name,res);return -1;}}static int tx_file_close(char* name){if(tx_file_open_flag != 0){tx_file_open_flag = 0;FRESULT res = f_close(&tx_fil);if(res != FR_OK){xprintf("close err %d\r\n",res);}return 0;}else{return -1;}}static uint32_t tx_file_read(uint32_t addr, uint8_t* buffer, uint32_t len){UINT br;FRESULT res = f_read(&tx_fil, buffer, len, &br);if(res != 0){xprintf("read err %d\r\n",res);}return br;}
测试输入help查看新添加的命令
输入
sxfile zhcy093.pdf 2573119 回车
Crt中菜单栏
Transfer->Receive Xmodem...
选择保存为文件zhcy093-1.pdf
传输中
传输完成
Xmodem协议最后不足包长需要填充0x1A，所以接收的文件中需要删除这部分，我们实现的xmodem会根据长度信息只保存指定长度没有这个问题。
删除这部分填充
检查校验信息，完全一致
四. 总结
得益于我们前面构造的shell和xmodem的轮子，可以很快的就实现文件传输的功能，这也是之前文章分享中要不断积累自己的轮子的原因。平常功能模块注意设计好框架接口，按照面向对象思想设计，考虑可移植性，这样就可以快速的移植使用。
