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今天介绍下我新完成的为Microchip的32位单片机PIC32MZ2048ECH144开发的UART bootloader程序。整个工程分两部分，第一部分是单片机端用XC32编译的bootloader程序PhsBoot_v5.0，另一部分是PC端用C#编译的bootloader通讯程序PhsLoader_v5.0。两者之间采用固定的协定通信合作，如下。
<STX><CMD><ADDRL><ADDRH><ADDRU><ADDRM><LEN><DATA>...<DATA><ETX>
STX - Start of packet indicator
ETX - End of packet indicator
LEN - The length of true data
DATA - General data 16 bytes, only first LEN of datas are true
CMD - Base command
ADDR - Address up to 32 bits ( ADDRL , ADDRH , ADDRH, ADDRM)
具体有以下Base command:
RD-VER: 0x00 -- Read Version Information （最终版本未实现）
RD_MEM： 0x01 -- Read Program Memory （最终版本未实现）
ER_MEM: 0x03 -- Erase Program Memory
WR_MEM： 0x02 -- Write Program Memory
WR_CFG： 0x04 -- Write Configuration Registers （最终版本未实现）
PhsLoader_v5.0
PhsLoader_v5.0是PC端的程序，负责打开串口，加载应用程序hex文件，并按照上面介绍的协定进行组包然后发送出去。PhsLoader_v5.0是用C#开发的包含UI的程序，UI如下图。
PhsLoader_v5.0 的主要实现代码如下
private void btnLoad_Click(object sender, EventArgs e)
{
btnDownload.Enabled = false;
textBoxStatus.AppendText("\r\nLoading hex file ...\r\n");
OpenFileDialog openDialog = new OpenFileDialog();
openDialog.Filter = "Hex files (*.hex)|*.hex";
if (openDialog.ShowDialog() == DialogResult.OK)
{
textBoxFile.Text = openDialog.FileName;
string[] pathArray = textBoxFile.Text.Split('\\');
int pathDeep = pathArray.Count();
textBoxStatus.AppendText("Hex file: " + pathArray[pathDeep - 1] + "\r\n");
textBoxStatus.AppendText("Loading completed\r\n");
HexParse loaderParse = new HexParse();
textBoxStatus.AppendText("Parsing hex file ...\r\n");
if (loaderParse.IsHexFile(textBoxFile.Text))
{
btnDownload.Enabled = true;
loaderLines = loaderParse.HexLines;
textBoxStatus.AppendText("Parsing completed\r\n");
}
else
{
textBoxStatus.ForeColor = Color.Red;
textBoxStatus.AppendText("Parsing failed\r\n");
textBoxStatus.ForeColor = Color.Black;
}
}
else
{
textBoxStatus.ForeColor = Color.Red;
textBoxStatus.AppendText("Loading failed\r\n\r\n");
textBoxStatus.ForeColor = Color.Black;
}
} private void btnDownload_Click(object sender, EventArgs e)
{
btnDownload.Enabled = false; if (!this.connect())
{
btnDownload.Enabled = true;
return;
} try
{
loaderReader = new StreamReader(textBoxFile.Text); }
catch (Exception ex)
{
Debug.WriteLine("Error: " + ex.Message);
textBoxStatus.ForeColor = Color.Red;
textBoxStatus.AppendText("Read hex file unsuccessfully\r\n");
textBoxStatus.ForeColor = Color.Black;
loaderReader.Close();
loaderSerial.Close();
btnDownload.Enabled = true;
return;
} loaderFrame = new SerialFrame();
if (!erase())
{
textBoxStatus.ForeColor = Color.Red;
textBoxStatus.AppendText("Erase unsuccessfully\r\n");
textBoxStatus.ForeColor = Color.Black;
loaderReader.Close();
loaderSerial.Close();
btnDownload.Enabled = true;
return;
} pBarLoading.Refresh();
pBarLoading.Visible = true;
pBarLoading.Value = 0;
pBarLoading.Maximum = loaderLines;
pBarLoading.Step = 1; string recordLine;
loaderUpperAddr = 0;
bool isNextLineUserID = false;
bool isNextLineConfigBits = false;
textBoxStatus.AppendText("\r\nDownloading hex file ...\r\n");
try
{
while (loaderReader.Peek() >= 0)
{
pBarLoading.PerformStep();
recordLine = loaderReader.ReadLine();
//if (recordLine.Contains(USER_ID_TOKEN) == true)
//{
// isNextLineUserID = true;
// continue;
//}
//else if (recordLine.Contains(CONFIG_BITS_TOKEN) == true)
//{
// isNextLineConfigBits = true;
// continue;
//}
if (recordLine.Contains(EXTEND_TOKEN) == true)
{
if (recordLine.Contains(USER_ID_TOKEN) == true)
{
isNextLineUserID = true;
continue;
}
else if (recordLine.Contains(CONFIG_BITS_TOKEN) == true)
{
const int ADDR_U_START_INDEX = 9;
const int ADDR_U_LENGTH = 4;
string addrU = recordLine.Substring(ADDR_U_START_INDEX, ADDR_U_LENGTH);
loaderUpperAddr = Convert.ToInt32(addrU, 16) << 16;
isNextLineConfigBits = true;
continue;
}
else if (recordLine.Contains(DSPIC_CONFIG_BITS_TOKEN) == true)
{
const int ADDR_U_START_INDEX = 9;
const int ADDR_U_LENGTH = 4;
string addrU = recordLine.Substring(ADDR_U_START_INDEX, ADDR_U_LENGTH);
loaderUpperAddr = Convert.ToInt32(addrU, 16) << 16;
isNextLineConfigBits = true;
continue;
}
else if (recordLine.Contains(PIC32_CONFIG_BITS_TOKEN) == true)
{
const int ADDR_U_START_INDEX = 9;
const int ADDR_U_LENGTH = 4;
string addrU = recordLine.Substring(ADDR_U_START_INDEX, ADDR_U_LENGTH);
loaderUpperAddr = Convert.ToInt32(addrU, 16) << 16;
isNextLineConfigBits = true;
continue;
}
else
{
const int ADDR_U_START_INDEX = 9;
const int ADDR_U_LENGTH = 4;
string addrU = recordLine.Substring(ADDR_U_START_INDEX, ADDR_U_LENGTH);
loaderUpperAddr = Convert.ToInt32(addrU, 16) << 16;
continue;
}
}
else if (recordLine.Contains(END_OF_HEX_FILE_TOKEN) == true)
{
break;
}
if (isNextLineUserID)
{
isNextLineUserID = false;
// do nothing;
}
else if (isNextLineConfigBits)
{
//if (!DownloadConfigLine(recordLine))
//{
// Debug.WriteLine("Error found during configuration bits programming");
// loaderReader.Close();
// loaderSerial.Close();
// btnDownload.Enabled = true;
// return;
//}
DownloadConfigLine(recordLine);
isNextLineConfigBits = false;
}
else
{
if (!DownloadDataLine(recordLine))
{
Debug.WriteLine("Error found during data programming");
loaderReader.Close();
loaderSerial.Close();
btnDownload.Enabled = true;
return;
}
//DownloadDataLine(recordLine);
}
}
}
catch (Exception ex)
{
Debug.WriteLine("Error: " + ex.Message);
textBoxStatus.ForeColor = Color.Red;
textBoxStatus.AppendText("Downloading failed\r\n");
textBoxStatus.ForeColor = Color.Black;
loaderSerial.Close();
loaderReader.Close();
btnDownload.Enabled = true;
return;
}
textBoxStatus.AppendText("Downloading completed\r\n"); if (!run())
{
textBoxStatus.ForeColor = Color.Red;
textBoxStatus.AppendText("Jump to Application unsuccessfully\r\n");
textBoxStatus.ForeColor = Color.Black;
loaderReader.Close();
loaderSerial.Close();
btnDownload.Enabled = true;
return;
}
loaderSerial.Close();
loaderReader.Close();
btnDownload.Enabled = true;
}
PhsBoot_v5.0
PhsBoot_v5.0是PIC32单片机端程序，放置在程序存储器中，放置的位置和我上一款PIC32 bootloader（HyperBootloader_PIC32)一样。所以他们的linker script也使用一样的。PhsBoot_v5.0主要功能是接收PhsLoader_v5.0发送过来的数据包，按照通信协定进行解包，分离出其中的地址和数据，并将数据按照PIC32的烧写时序烧录到对应的地址中。PhsBoot_v5.0 是用XC32开发的，主要的实现代码如下。
if (lineReceived)
{
if ((frameBuffer[0] == STX) && (frameBuffer[BUFFER_MAX-1] == ETX))
{
switch (frameBuffer[CMD_INDEX])
{
case WR_MEM:
SourceAddr.byte.LB = frameBuffer[ADDRL_INDEX];
SourceAddr.byte.HB = frameBuffer[ADDRH_INDEX];
SourceAddr.byte.UB = frameBuffer[ADDRU_INDEX];
SourceAddr.byte.MB = frameBuffer[ADDRM_INDEX];
if ((SourceAddr.word.HW == 0x1fc0))
{
SendResponse();
break;
}
int ix;
for (ix=0;ix<frameBuffer[LEN_INDEX];)
{
pData.byte.LB = frameBuffer[LEN_INDEX+1+ix++];
pData.byte.HB = frameBuffer[LEN_INDEX+1+ix++];
pData.byte.UB = frameBuffer[LEN_INDEX+1+ix++];
pData.byte.MB = frameBuffer[LEN_INDEX+1+ix++];
NVMWriteWord(SourceAddr.Val, pData.Val);
SourceAddr.Val += 4;
}
//Uart_Putc(0x55); //for debug
SendResponse();
break;
case WR_CFG:
//WriteWordMem(CM_WORD_WRITE);
//Uart_Putc(0x00); // for debug
SendResponse();
break;
case ER_MEM:
//EraseMem();
for (EraseAddr.Val = ERASE_FLASH_BASE_ADDRESS; EraseAddr.Val < ERASE_FLASH_END_ADDRESS;)
{
NVMErasePage(EraseAddr.Val);
EraseAddr.Val += PAGE_SIZE;
}
//Uart_Putc(0xaa); // for debug
SendResponse();
break;
case RUN_APP:
//Uart_Putc(0xff); // for debug
SendResponse();
TRISCSET = 0x2000; // RC13 Input
LATCCLR = 0x6000; // Clear LATC
IPC28CLR = 0x1F00; // Clear IPC28
LATHCLR = (1<<0);
TRISHSET = (1<<0);
CoreT_DelayMs(10);
U1MODE = 0x0;
U1STA = 0x0;
(*((void(*)(void))USER_APP_RESET_ADDRESS))();
default:
break;
}
}
lineReceived = 0;
lineBytes = 0;
readBytes = 0;
}
如何使用PhsLoader_v5.0和PhsBoot_v5.0
1. 使用XC32编译PhsBoot_v5.0（编译前，需先修改linker script）。
2. 使用pickit3烧录PhsBoot_v5.0的Hex文件到目标板中。
3. 拔除pickit3烧录器
4. 连接目标板与PC的串口，打开PhsLoader_v5.0，选择COM端口，BAUD RATE。
5. 点击PhsLoader_v5.0用户界面上的“.."按钮加载需要烧录的应用程序Hex文件（编译前，需先修改linker script）
6. 重启目标板，等到LED1 灯亮了，立刻在PhsLoader_v4.0界面上点击Download按钮。如果超时未点击Download按钮，会自动跳转到上次烧录的应用程序中去。
7. 烧录完毕，再次重启目标板, 6秒后目标板开始正常运行应用程序。
之后每次更新应用程序，只需重复步骤 4 ~ 7 就可以了。注意，整个烧录过程未能实现Configuration Bits的烧写，所以需要保持应用程序的Configuration Bits和Bootloader的Configuration Bits一致。