UBOOT 串口测试

打开设置 

serial_init_dev 中设置波特率，因为_serial_setbrg调用的是全局的gd->baudrate，所以要打开某个串口是需要先保留gd->baudrate的最先值，完成后在恢复现场。

读写

void _serial_putc (const uchar c, const int dev_index)
{
     S3C64XX_UART *const uart = S3C64XX_GetBase_UART(dev_index);
#ifdef CONFIG_MODEM_SUPPORT
        if (be_quiet)
                return;
#endif
        /* wait for room in the tx FIFO */
        while (!(uart->UTRSTAT & 0x2));

#ifdef CONFIG_HWFLOW
        /* Wait for CTS up */
        while(hwflow && !(uart->UMSTAT & 0x1));
#endif
        uart->UTXH = c;
}

int _serial_getc (const int dev_index)
{
    S3C64XX_UART *const uart = S3C64XX_GetBase_UART(dev_index);

    /* wait for character to arrive */
    while (!(uart->UTRSTAT & 0x1));

    return uart->URXH & 0xff;
}