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":"+D" (buf), "+c"(len):"a"(ch):"memory");
  27 }
  28
  29 int putchar(int ch)
  30 {
  31     com32sys_t regs;
  32
  33     memset(&regs, 0, sizeof regs);
  34
  35     if (ch == '\n') {
  36         /* \n -> \r\n */
  37         putchar('\r');
  38     }
  39
  40     regs.eax.b[1] = 0x02;
  41     regs.edx.b[0] = ch;
  42     __com32.cs_intcall(0x21, &regs, NULL);
  43
  44     return ch;
  45 }
  46
  47 /* Note: doesn't put '\n' like the stdc version does */
  48 int puts(const char *s)
  49 {
  50     int count = 0;
  51
  52     while (*s) {
  53         putchar(*s);
  54         count++;
  55         s++;
  56     }
  57
  58     return count;
  59 }