How to rework "printf" function to use for two UARTS in the cygnal's MCU?

 RE: How to rework

#ifdef DBG
#    define debug
#else
#    define debug while (0)
#endif

// Usage: single line
debug printf("Got here\n");

// Usage: multiple line
debug
{
    g_errno = 12;
    printf("Got error, %d\n", g_errno);
}

 RE: How to rework

//-----------------------------------------------
#include "stdio.h"

volatile unsigned char sio_selector = 0;

//-----------------------------------------------
char putchar (char c)
{
if (sio_selector == 0)
  {
  while (!TI_0);  /* wait until transmitter ready */
  TI_0 = 0;
  SBUF0 = c;      /* output character */
  }
else
  {
  while (!TI_1);  /* wait until transmitter ready */
  TI_1 = 0;
  SBUF1 = c;      /* output character */
  }

return (c);
}


//-----------------------------------------------
char _getkey (void)
{
char c;

if (sio_selector == 0)
  {
  while (!RI_0);  /* wait for a character */
  c = SBUF0;
  RI_0 = 0;       /* clear receive interrupt bit */
  }
else
  {
  while (!RI_1);  /* wait for a character */
  c = SBUF1;
  RI_1 = 0;       /* clear receive interrupt bit */
  }

return (c);
}


//-----------------------------------------------
void main (void)
{
//Initialize SIO0
//Initialize SIO1

while (1)
  {
  sio_selector = 0;
  printf ("Serial Port 0\r\n");

  sio_selector = 1;
  printf ("Serial Port 1\r\n");
  }
}
//-----------------------------------------------