【瑞萨RA4系列开发板体验】printf+hello world

今天看了看Jlink v10，最便宜的也得400块，太贵了，但是要调试程序，只有选择printf来实现了，所以先把printf来实现。
1、按照常规的新建好工程：

2、打开资料《RA2E1/RA2L1入门指南》的《# 瑞萨e2studio----打印函数(printf、sprintf)的实现》这篇文章，他们的芯片型号不一样，但是操作也是基本相同的。
3、按照以后步步骤添加uart0:

4、选好IO为P101、P100为RX、TX

5、设置E2STUDIO堆栈

6、修改e2studio的重定向printf设置C++ 构建->设置->GNU ARM Cross C Linker->Miscellaneous去掉Other linker flags中的 “--specs=rdimon.specs”

7、完整的halt_entry.c内容如下：

#include "hal_data.h"
#include <stdio.h>
FSP_CPP_HEADER
void R_BSP_WarmStart(bsp_warm_start_event_t event);
FSP_CPP_FOOTER

fsp_err_t err = FSP_SUCCESS;unsigned char send_buff[100];
volatile bool uart_send_complete_flag = false;
void user_uart_callback (uart_callback_args_t * p_args)
{
    if(p_args->event == UART_EVENT_TX_COMPLETE)
    {
        uart_send_complete_flag = true;
    }
}

#ifdef __GNUC__                                 //串口重定向
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif
PUTCHAR_PROTOTYPE
{
    err = R_SCI_UART_Write(&g_uart0_ctrl, (uint8_t *)&ch, 1);
    if(FSP_SUCCESS != err) __BKPT();
    while(uart_send_complete_flag == false){}
    uart_send_complete_flag = false;
    return ch;
}
int _write(int fd,char *pBuffer,int size)
{
    for(int i=0;i<size;i++)
    {
        __io_putchar(*pBuffer++);
    }
    return size;
}

/*******************************************************************************************************************//**
 * main() is generated by the RA Configuration editor and is used to generate threads if an RTOS is used.  This function
 * is called by main() when no RTOS is used.
 **********************************************************************************************************************/
void hal_entry(void)
{
    /* TODO: add your own code here */
    err = R_SCI_UART_Open(&g_uart0_ctrl, &g_uart0_cfg);
    assert(FSP_SUCCESS == err);
    unsigned char buff[]="RA E2STUDIO";
    uint8_t buff_len = strlen(buff);
    err = R_SCI_UART_Write(&g_uart0_ctrl, buff, buff_len);
    if(FSP_SUCCESS != err) __BKPT();
    while(uart_send_complete_flag == false){}
    uart_send_complete_flag = false;
    sprintf(send_buff, "\nHello World!.\n");
    uint8_t len = strlen(send_buff);
    err = R_SCI_UART_Write(&g_uart0_ctrl, send_buff, len);
    if(FSP_SUCCESS != err) __BKPT();
    while(uart_send_complete_flag == false){}
    uart_send_complete_flag = false;
    memset(send_buff, '\0', sizeof(100));
    int int_i=55;
    float float_i=66.20f;
    char char_i[]="hello e2studio";
    while(1)
    {
        printf("int_i=%d\n",int_i);
        printf("float_i=%.2f\n",float_i);
        printf("char_i='%s'\n",char_i);
        R_BSP_SoftwareDelay(1000, BSP_DELAY_UNITS_MILLISECONDS);
        // NOLINT100->160
    }

#if BSP_TZ_SECURE_BUILD
    /* Enter non-secure code */
    R_BSP_NonSecureEnter();
#endif
}

/*******************************************************************************************************************//**
 * This function is called at various points during the startup process.  This implementation uses the event that is
 * called right before main() to set up the pins.
 *
 * @param[in]  event    Where at in the start up process the code is currently at
 **********************************************************************************************************************/
void R_BSP_WarmStart(bsp_warm_start_event_t event)
{
    if (BSP_WARM_START_RESET == event)
    {
#if BSP_FEATURE_FLASH_LP_VERSION != 0

        /* Enable reading from data flash. */
        R_FACI_LP->DFLCTL = 1U;

        /* Would normally have to wait tDSTOP(6us) for data flash recovery. Placing the enable here, before clock and
         * C runtime initialization, should negate the need for a delay since the initialization will typically take more than 6us. */
#endif
    }

    if (BSP_WARM_START_POST_C == event)
    {
        /* C runtime environment and system clocks are setup. */

        /* Configure pins. */
        R_IOPORT_Open (&g_ioport_ctrl, g_ioport.p_cfg);
    }
}

#if BSP_TZ_SECURE_BUILD

BSP_CMSE_NONSECURE_ENTRY void template_nonsecure_callable ();

/* Trustzone Secure Projects require at least one nonsecure callable function in order to build (Remove this if it is not required to build). */
BSP_CMSE_NONSECURE_ENTRY void template_nonsecure_callable ()
{

}
#endif

8、编译后烧录到开发板：USB转TTL接到P100、P101上，打开串口助手，就可以收到开发板发出来的信息了：

【总结】根据教程一步一步就可以实现配置uart0，非常简单。