sample/conio.c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60

/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2001-2008 H. Peter Anvin - All Rights Reserved
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
 *   Boston MA 02111-1307, USA; either version 2 of the License, or
 *   (at your option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

/*
 * conio.c
 *
 * Output to the screen
 */

#include <com32.h>
#include <stdarg.h>

#define NULL ((void *)0)

static inline void memset(void *buf, int ch, unsigned int len)
{
  asm volatile("cld; rep; stosb"
	       : "+D" (buf), "+c" (len) : "a" (ch) : "memory");
}

int putchar(int ch)
{
  com32sys_t regs;

  memset(&regs, 0, sizeof regs);

  if ( ch == '\n' ) {
    /* \n -> \r\n */
    putchar('\r');
  }

  regs.eax.b[1] = 0x02;
  regs.edx.b[0] = ch;
  __com32.cs_intcall(0x21, &regs, NULL);

  return ch;
}

/* Note: doesn't put '\n' like the stdc version does */
int puts(const char *s)
{
  int count = 0;

  while ( *s ) {
    putchar(*s);
    count++;
    s++;
  }

  return count;
}