#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>

#define UART_PRINTF_BAUDRATE 115200

const uint8_t HEX_TABLE[16] = { '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};


int __io_getchar(void)
{
  //return USART_ReceiveData(USART1);
  return 0;
}

int __io_putchar(int ch)
{
  // UART_SendByte((uint8_t)ch);
  return ch;
}

__attribute__((weak)) int _read(int file, char *ptr, int len)
{
    (void)file;
    int DataIdx;
    for (DataIdx = 0; DataIdx < len; DataIdx++)
    {
        *ptr++ = __io_getchar();
    }
    return len;
}

__attribute__((weak)) int _write(int file, char *ptr, int len)
{
    (void)file;
    int DataIdx;
    for (DataIdx = 0; DataIdx < len; DataIdx++)
    {
        __io_putchar(*ptr++);
    }
    return len;
}


__attribute__((weak)) int _isatty(int fd)
{
    if (fd >= STDIN_FILENO && fd <= STDERR_FILENO)
        return 1;

    errno = EBADF;
    return 0;
}

__attribute__((weak)) int _close(int fd)
{
    if (fd >= STDIN_FILENO && fd <= STDERR_FILENO)
        return 0;

    errno = EBADF;
    return -1;
}

__attribute__((weak)) int _lseek(int fd, int ptr, int dir)
{
    (void)fd;
    (void)ptr;
    (void)dir;

    errno = EBADF;
    return -1;
}

__attribute__((weak)) int _fstat(int fd, struct stat *st)
{
    if (fd >= STDIN_FILENO && fd <= STDERR_FILENO)
    {
        st->st_mode = S_IFCHR;
        return 0;
    }

    errno = EBADF;
    return 0;
}