sample/conio.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2001-2008 H. Peter Anvin - All Rights Reserved
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   8  *   Boston MA 02111-1307, USA; either version 2 of the License, or
   9  *   (at your option) any later version; incorporated herein by reference.
  10  *
  11  * ----------------------------------------------------------------------- */
  12
  13 /*
  14  * conio.c
  15  *
  16  * Output to the screen
  17  */
  18
  19 #include <com32.h>
  20 #include <stdarg.h>
  21
  22 #define NULL ((void *)0)
  23
  24 static inline void memset(void *buf, int ch, unsigned int len)
  25 {
  26   asm volatile("cld; rep; stosb"
  27                : "+D" (buf), "+c" (len) : "a" (ch) : "memory");
  28 }
  29
  30 int putchar(int ch)
  31 {
  32   com32sys_t regs;
  33
  34   memset(&regs, 0, sizeof regs);
  35
  36   if ( ch == '\n' ) {
  37     /* \n -> \r\n */
  38     putchar('\r');
  39   }
  40
  41   regs.eax.b[1] = 0x02;
  42   regs.edx.b[0] = ch;
  43   __com32.cs_intcall(0x21, &regs, NULL);
  44
  45   return ch;
  46 }
  47
  48 /* Note: doesn't put '\n' like the stdc version does */
  49 int puts(const char *s)
  50 {
  51   int count = 0;
  52
  53   while ( *s ) {
  54     putchar(*s);
  55     count++;
  56     s++;
  57   }
  58
  59   return count;
  60 }