通过Lua小程序，我们可以方便方便的在线方式做串口固件烧录，也可以离线方式运行Lua小程序做烧录。

本次是说明是采用H7-TOOL串口方式连接我们V7板子做的操作说明。

【协议说明】

1、发送固件大小：符号‘*’ 来同步，然后发送固件大小，板子收到后，回复0x30表示擦除相应扇区大小成功，回复0x60表示擦除失败。

2、发送固件数据：符号‘$’ 来同步，然后发送固件数据，每次224字节大小，板子收到后，回复0x30表示数据编程成功，回复0x60表示擦除失败。如此反复，一直到发送完毕。

3、发送结束命令：符号‘#’ 表示传输结束，目标板可以加载到APP运行了。

【硬件接线】

H7-TOOL通过TTL串口接到V7板子的TTL串口上：



 

【准备工作】

当前上位机还没有做专门的串口脱机烧录一键下载界面，需要手动将Lua文件和app固件存到

1、H7-TOOL进入虚拟U盘

上电首界面长按S键 -> 系统设置 -> USB eMMC磁盘， 进入eMMC模拟U盘后，在如下路径新建文件夹串口脱机烧录

将如下两个文件存到新建的文件夹下

app.bin (50.03 KB)

uartfirmware.lua (3.04 KB)

2、将目标板程序下载到V7开发板

 基于V7的串口脱机烧录目标板程序.7z (2 MB)

【在线方式操作说明】

H7-TOOL可以采用USB，以太网或者WiFi方式连接上位机。

将前面lua小程序uartfirmware.lua的内容复制到如下窗口：

点击下面的执行按钮就可以看到动图更新了：

【离线方式操作说明】

操作TOOL显示屏，进入Lua小程序界面：

执行uartfirmware.lua小程序。

执行效果如下：

【Lua小程序简单说明】

注释非常详细：

-------------------------------------------------------
--   
--     H7-TOOL 串口脱机烧录Lua小程序实现
--
-------------------------------------------------------        
local str
local len
local bytes
local bin
local offset
local value
local count
local filesize
local byte0
local byte1
local byte2
local byte3
local filepath = "0:/H7-TOOL/Lua/串口脱机烧录/app.bin" -- 表示串口脱机烧录文件夹下存的文件
local filepath1 = "0:/H7-TOOL/Lua/串口脱机烧录"        -- 浏览串口脱机烧录文件下存的文件
 
 
-------------------------------------------------------
--   第1步：浏览串口脱机烧录文件夹下存的文件
-------------------------------------------------------
f_dir(filepath1)
print()
 
-------------------------------------------------------
--   第2步：设置串口波特率115200，奇偶校验位无，数据位8，停止位1
-------------------------------------------------------
uart_cfg(1, 115200, 0, 8, 1)
 
-------------------------------------------------------
--   第3步：发送固件大小，方便目标板擦除相应大小扇区
-------------------------------------------------------
-- 获取固件大小
filesize=f_size(filepath)    
print("============================================")
str= string.format("固件大小：%d",filesize)
print(str)
 
-- 将固件大小转换成四个字节
byte0 = ((filesize >> 0) & 0xFF)
byte1 = ((filesize >> 8) & 0xFF)
byte2 = ((filesize >> 16) & 0xFF)
byte3 = ((filesize >> 24) & 0xFF)
 
-- 发送固件大小给目标板
uart_send(1, "*")    --发送*号表示固件大小命令
uart_send(1, string.char(byte0))  --发送固件大小
uart_send(1, string.char(byte1))
uart_send(1, string.char(byte2))
uart_send(1, string.char(byte3))
print("执行扇区擦除.....")
 
-- 等待返回数据，返回0x30表示擦除成功
len, str = uart_recive(1, 1, 10000)
if(str == '\x30') then
  print("扇区擦除执行完毕")
else
  print("扇区擦除执行失败")
end
 
-------------------------------------------------------
--   第4步：发送固件大小
-------------------------------------------------------
offset = 0
-- 第1个参数是路径，第2个参数的偏移地址，第3个参数读取大小
-- 返回值bytes表示读取的字节数，bin表示都回的数据
bytes, bin = f_read(filepath, 0, 224)
offset = offset + bytes
 
-- 读取数据为0，表示传输完毕
while(bytes > 0)
do
    -- 发送$表示开始传输固件命令
    uart_send(1, "$")
    uart_send(1, string.char(bytes))
 
    -- 发送固件数据给目标板
    uart_send(1, bin)
     
    -- 等待目标板返回确认数据0x30
    len, str = uart_recive(1, 1, 20000)
    -- 返回0x30表示发送成功
    if(str == '\x30') then
      bytes, bin = f_read(filepath, offset, 224)  -- 继续读取数据
      offset = offset + bytes
      if(bytes ~= 0) then                         -- 读取不为0，打印发送的总字节数
         print("发送固件:", offset)
      end
    else
        print("固件传输失败")
    end
     
end
 
-------------------------------------------------------
--   第5步：发送传输结束命令
-------------------------------------------------------
uart_send(1, "#")
print("固件传输完成")
 
-------------------------------------------------------
--  end of file
-------------------------------------------------------

【目标板程序简单说明】

最关键的就是串口程序处理：

void DemoUartUpdate(void)
{
        uint8_t cmd;
        uint8_t ucStatus = 0; 
        uint32_t SectorCount = 0;
        uint32_t SectorRemain = 0;
        uint32_t i;
    uint32_t TotalSize = 0;
        uint8_t ucState;
         
         
        bsp_StartAutoTimer(0, 500);       
         
        while (1)
        {
               
                if (bsp_CheckTimer(0))        
                {            
                       
                        bsp_LedToggle(2);
                }
 
                if (comGetChar(COM1, &cmd))       
                {
                        switch (ucStatus)
                        {
                                case 0:
                                       
                                        if(cmd == '$')
                                        {
                                                RecCplt = 0;
                                                ucStatus = 1;        
                                        }
                                         
                                       
                                        if(cmd == '#')
                                        {
                                                RecCount = 0;
                                                RecCplt = 1;
                                                JumpToApp();
                                        }
                                         
                                       
                                        if(cmd == '*')
                                        {
                                                ucStatus = 3;
                                        }
                                        break;
                                         
                               
                                case 1:
                                        RecSize = cmd;
                                        ucStatus = 2;
                                        break;
                                            
                               
                                case 2:
                                        buf[RecCount0] = cmd;
                                        
                                       
                                        if(RecCount0 == (RecSize - 1))
                                        {
                                                ucStatus = 0;
                                                RecCount0 = 0;
                                                 
                                               
                                                ucState = bsp_WriteCpuFlash((uint32_t)(AppAddr + TotalSize),  (uint8_t *)buf, RecSize);
                                                TotalSize += RecSize;
                                                 
                                               
                                                if(ucState != 0)
                                                {
                                                       
                                                        comSendChar(COM1, 0x60);
                                                }
                                                 
                                               
                                                comSendChar(COM1, 0x30);
                                        }
                                        else
                                        {
                                                RecCount++;
                                                RecCount0++;
                                        }
                                        break;
                                         
                               
                                case 3:
                                        buf[RecCount0] = cmd;
                                        
                                        if(RecCount0 == 3)
                                        {
                                                ucStatus = 0;
                                                RecCount0 = 0;
                                                filesize = buf[0] + (buf[1] << 8) + (buf[2] << 16) + (buf[3] << 24);
                                                uwAppSize = filesize;
                                                SectorCount = filesize/(128*1024);
                                                SectorRemain = filesize%(128*1024);        
                                                 
                                                for(i = 0; i < SectorCount; i++)
                                                {
                                                        bsp_EraseCpuFlash((uint32_t)(AppAddr + i*128*1024));
                                                }
                                                 
                                                if(SectorRemain)
                                                {
                                                        bsp_EraseCpuFlash((uint32_t)(AppAddr + i*128*1024));
                                                }
                                                 
                                               
                                                comSendChar(COM1, 0x30);
                                        }
                                        else
                                        {
                                                RecCount0++;
                                        }
                                        break;
                        }
                }
        }
}

【参考资料】

之前更新过三期BootLoader的视频教程，可以作为参考学习：

单片机bootloader专题，启动，跳转配置和调试下载的各种用法
https://www.armbbs.cn/forum.php?mod=viewthread&tid=112792

基于NAND，eMMC，SD卡和U盘的BootLoader实战，带CRC完整性校验
https://www.armbbs.cn/forum.php?mod=viewthread&tid=113053

单片机BootLoader的AES加密实战，含上位机和下位机代码全开源
https://www.armbbs.cn/forum.php?mod=viewthread&tid=113361