参照模板自己写了一遍，期间出现很多问题。比如定义全局uart0设备指针后未初始化，导致RT_ASSERT(device != RT_NULL)执行，使设备注册时死机。
初始化函数没写对，也导致了程序崩溃。
// uart.h// 2015.12.18 by Huangtao#ifndef __UART_H__#define __UART_H__#include#include #include #include #define RT_SERIAL_EVENT_RX_IND 0x01 /* Rx indication */#define RT_SERIAL_EVENT_TX_DONE 0x02 /* Tx complete */#define RT_SERIAL_EVENT_RX_DMADONE 0x03 /* Rx DMA transfer done */#define RT_SERIAL_EVENT_TX_DMADONE 0x04 /* Tx DMA transfer done */#define RT_SERIAL_EVENT_RX_TIMEOUT 0x05 /* Rx timeout */#define UART_RX_BUFFER_SIZE 64typedef struct uartport{ volatile rt_uint32_t ulcon; volatile rt_uint32_t ucon; volatile rt_uint32_t ufcon; volatile rt_uint32_t umcon; volatile rt_uint32_t ustat; volatile rt_uint32_t urxb; volatile rt_uint32_t ufstat; volatile rt_uint32_t umstat; volatile rt_uint32_t utxh; volatile rt_uint32_t urxh; volatile rt_uint32_t ubrd;}uartport;// 中断接收时的ringbuffer缓冲区定义struct uart_int_rx{ rt_uint8_t rx_buffer[UART_RX_BUFFER_SIZE]; rt_uint32_t read_index, save_index;};// 串口设备struct uart_device{ uartport* uart_device; struct uart_int_rx* int_rx;};extern rt_err_t rt_hw_uart_register(rt_device_t device, const char* name, rt_uint32_t flag, struct uart_device *uart);extern void rt_hw_uart_isr(rt_device_t device);extern void rt_hw_uart_init(void);#endif
// uart.c// uart驱动// 2015.12.18 by Huangtao#include "uart.h"#define baudrate 115200 extern rt_uint32_t PCLK;// 设置好uart0的实际物理地址#define MYUART0 ((struct uartport *)&U0BASE)struct uart_int_rx uart0_int_rx;struct uart_device myUart0 ={ MYUART0, &uart0_int_rx};// 全局uart0设备struct rt_device myuart0_dev;rt_device_t myUart0_device = &myuart0_dev;// 初始化static rt_err_t uart_init(rt_device_t dev){ struct uart_device* uart; // 获得真实的UART设备对象 uart = (struct uart_device*)dev->user_data; // 判断设备是否已经激活了 if (!(dev->flag & RT_DEVICE_FLAG_ACTIVATED)) { // 如果是中断接收模式，初始化接收的缓冲区 if (dev->flag & RT_DEVICE_FLAG_INT_RX) { rt_memset(uart->int_rx->rx_buffer, 0, sizeof(uart->int_rx->rx_buffer)); uart->int_rx->read_index = 0; uart->int_rx->save_index = 0; } // 设置设备为激活状态 dev->flag |= RT_DEVICE_FLAG_ACTIVATED; } return RT_EOK;}// 打开设备static rt_err_t uart_open(rt_device_t dev, rt_uint16_t oflag){ RT_ASSERT(dev != RT_NULL); return RT_EOK;}// 关闭设备static rt_err_t uart_close(rt_device_t dev){ RT_ASSERT(device != RT_NULL); return RT_EOK;}// 从设备中读取数据static rt_size_t uart_read(rt_device_t dev, rt_off_t pos, void* buffer, rt_size_t size){ rt_base_t level; rt_uint8_t* ptr; struct uart_device* uart; struct uart_int_rx* int_rx; ptr = buffer; uart = (struct uart_device*)dev->user_data; int_rx = uart->int_rx; if (ptr == RT_NULL) { return RT_ENOMEM; } if (dev->flag & RT_DEVICE_FLAG_INT_RX) { // 中断模式接收，中断模式接收在中断服务例程中已预先收取到缓冲区中， // 所以这里只需要从缓冲区中复制出数据 while (size) { level = rt_hw_interrupt_disable(); if (int_rx->read_index != int_rx->save_index) { *ptr++ = int_rx->rx_buffer[int_rx->read_index]; size--; int_rx->read_index ++; if (int_rx->read_index >= UART_RX_BUFFER_SIZE) int_rx->read_index = 0; rt_hw_interrupt_enable(level); } else { rt_hw_interrupt_enable(level); break; } } } else { // 轮询模式，直接从串口设备中读取数据 while ((rt_uint32_t)ptr - (rt_uint32_t)buffer < size) { while (uart->uart_device->ustat & RT_SERIAL_EVENT_RX_IND) { *ptr = uart->uart_device->urxh & 0xff; ptr ++; } } } // 返回读取到的字节数 return (rt_uint32_t)ptr - (rt_uint32_t)buffer;}// 向设备中写入数据static rt_size_t uart_write(rt_device_t dev, rt_off_t pos, const void* buffer, rt_size_t size){ rt_uint8_t* ptr; struct uart_device* uart; ptr = (rt_uint8_t*)buffer; uart = (struct uart_device*)dev->user_data; if (ptr == RT_NULL) { return RT_ENOMEM; } if ((dev->flag & RT_DEVICE_FLAG_INT_TX)) { } else { // 直接写入 while (size) { if (*ptr == '\n' && (dev->flag & RT_DEVICE_FLAG_STREAM)) { while (!(uart->uart_device->ustat & RT_SERIAL_EVENT_TX_DONE)); uart->uart_device->utxh = '\r'; } //wait Tx empty while(!(uart->uart_device->ustat & RT_SERIAL_EVENT_TX_DONE)); uart->uart_device->utxh = (*ptr & 0xFF); ++ptr; --size; } } // 返回写入成功的字节数 return (rt_uint32_t)ptr - (rt_uint32_t)buffer;}// 设备控制操作// 还未实现static rt_err_t uart_control(rt_device_t dev, rt_uint8_t cmd, void *args){ RT_ASSERT(dev != RT_NULL); switch (cmd) { case RT_DEVICE_CTRL_SUSPEND: // 挂起设备 dev->flag |= RT_DEVICE_FLAG_SUSPENDED; break; case RT_DEVICE_CTRL_RESUME: // 唤醒设备 dev->flag &= ~RT_DEVICE_FLAG_SUSPENDED; break; } return RT_EOK;}// 向系统中注册串口设备rt_err_t rt_hw_uart_register(rt_device_t device, const char* name, rt_uint32_t flag, struct uart_device *uart){ RT_ASSERT(device != RT_NULL); device->type = RT_Device_Class_Char; device->rx_indicate = RT_NULL; device->tx_complete = RT_NULL; // 设置设备驱动公共接口函数 device->init = uart_init; device->open = uart_open; device->close = uart_close; device->read = uart_read; device->write = uart_write; device->control = uart_control; device->user_data = uart; // 注册设备 rt_device_register(device, name, RT_DEVICE_FLAG_RDWR | flag); return RT_EOK;}// ISR for serial interruptvoid rt_hw_uart_isr(rt_device_t device){ rt_base_t level; struct uart_device* uart; struct uart_int_rx* int_rx; uart = (struct uart_device*)device->user_data; int_rx = uart->int_rx; RT_ASSERT(device->flag & RT_DEVICE_FLAG_INT_RX); while (uart->uart_device->ustat & RT_SERIAL_EVENT_RX_IND) { level = rt_hw_interrupt_disable(); int_rx->rx_buffer[int_rx->save_index] = (uart->uart_device->urxh & 0xff); int_rx->save_index ++; if(int_rx->save_index >= UART_RX_BUFFER_SIZE) int_rx->save_index = 0; // if the next position is read index, discard this 'read char' if(int_rx->save_index == int_rx->read_index) { int_rx->read_index ++; if(int_rx->read_index >= UART_RX_BUFFER_SIZE) int_rx->read_index = 0; } rt_hw_interrupt_enable(level); } // 接收回调函数 if(device->rx_indicate != RT_NULL) { rt_size_t rx_length; level = rt_hw_interrupt_disable(); // get rx length rx_length = int_rx->read_index > int_rx->save_index ? UART_RX_BUFFER_SIZE - int_rx->read_index + int_rx->save_index : int_rx->save_index - int_rx->read_index; rt_hw_interrupt_enable(level); device->rx_indicate(device, rx_length); }}// This function will handle serial (参考board.c)static void rt_uart_handler(int vector, int event){ INTSUBMSK |= (BIT_SUB_RXD0); rt_hw_uart_isr(myUart0_device); SUBSRCPND |= BIT_SUB_RXD0; // Unmask sub interrupt (RXD0) INTSUBMSK &=~(BIT_SUB_RXD0);}void rt_hw_uart_init(void){ // TX0 GPH2 // RX0 GPH3 int i; // UART0 port configure GPHCON |= 0xAA; // PULLUP is disable GPHUP |= 0xF; // uart FIFO控制寄存器 Disable[0]=0 myUart0.uart_device->ufcon = 0x0; // uart 模式控制寄存器 myUart0.uart_device->umcon = 0x0; // uart line控制寄存器 8 bit, 1 stop myUart0.uart_device->ulcon = 0x3; // uart控制寄存器 // 中断或轮询模式发送[3:2]=01，中断或轮询模式接收[1:0]=01 myUart0.uart_device->ucon = 0x245; // Set uart0 bps myUart0.uart_device->ubrd = (rt_int32_t)(PCLK / (baudrate * 16)) - 1; // output PCLK to UART0/1, PWMTIMER CLKCON |= 0x0D00; for (i = 0; i < 100; i++); // install uart0 isr INTSUBMSK &= ~(BIT_SUB_RXD0); rt_hw_interrupt_install(INTUART0, rt_uart_handler, RT_NULL, "UART0"); rt_hw_interrupt_umask(INTUART0);} 使用时：
在rt_application_init(void)函数中注册和初始化：
rt_hw_uart_register(myUart0_device, "myUart0", RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX | RT_DEVICE_FLAG_STREAM, &myUart0);rt_hw_uart_init();
然后在自己的线程中使用，比如：
// lcd_td35 测试void rt_lcd_thread_entry(void *parameter){ struct RTC_Date getDate; unsigned char rtcBuffer[20]; unsigned char rx[50] = { '\0'}; unsigned char *rxBuffer = &rx[0]; Lcd_TD35_Init(); myUart0_device = rt_device_find("myUart0"); if (myUart0_device != RT_NULL) { // 初始化设备 rt_device_init(myUart0_device); // 打开设备 rt_device_open(myUart0_device, RT_DEVICE_OFLAG_RDWR | RT_DEVICE_FLAG_INT_RX | RT_DEVICE_FLAG_STREAM); } rt_device_write(myUart0_device, 0, "Hello World !\0", 15); while(1) { Lcd_ClearScr(0); RTC_Time_Get(&getDate,rtcBuffer); Draw_String(0, 0, 200, 100, 0xf800, 12, 1, rtcBuffer); Draw_String(150, 0, 200, 100, 0xf800, 12, 1, "by Huangtao"); rt_device_read(myUart0_device, 0, rxBuffer, 10); Draw_String(0, 200, 200, 100, 0xf800, 12, 1, rxBuffer); rt_device_write(myUart0_device, 0, rxBuffer, 10); rt_thread_delay(10); }}