FreeRTOS/Demo/RISC-V_RV32_SiFive_HiFive1-RevB_FreedomStudio/freedom-metal/src/tty.c

/* Copyright 2018 SiFive, Inc */
/* SPDX-License-Identifier: Apache-2.0 */

#include <metal/uart.h>
#include <metal/tty.h>
#include <metal/machine.h>

#if defined(__METAL_DT_STDOUT_UART_HANDLE)
/* This implementation serves as a small shim that interfaces with the first
 * UART on a system. */
int metal_tty_putc(int c)
{
    if (c == '\n') {
        metal_tty_putc_raw( '\r' );
    }
    return metal_tty_putc_raw( c );
}

int metal_tty_putc_raw(int c)
{
    return metal_uart_putc(__METAL_DT_STDOUT_UART_HANDLE, c);
}

int metal_tty_getc(int *c)
{
   do {
        metal_uart_getc( __METAL_DT_STDOUT_UART_HANDLE, c );
        /* -1 means no key pressed, getc waits */
    } while( -1 == *c )
        ;
    return 0;
}

#ifndef __METAL_DT_STDOUT_UART_BAUD
#define __METAL_DT_STDOUT_UART_BAUD 115200
#endif

static void metal_tty_init(void) __attribute__((constructor));
static void metal_tty_init(void)
{
    metal_uart_init(__METAL_DT_STDOUT_UART_HANDLE, __METAL_DT_STDOUT_UART_BAUD);
}
#else
/* This implementation of putc doesn't actually do anything, it's just there to
 * provide a shim that eats all the characters so we can ensure that everything
 * can link to metal_tty_putc. */
int nop_putc(int c) __attribute__((section(".text.metal.nop.putc")));
int nop_putc(int c) { return -1; }
int metal_tty_putc(int c) __attribute__((weak, alias("nop_putc")));
#pragma message("There is no default output device, metal_tty_putc() will throw away all input.")
#endif