libc/stdio/getch.c

   1 /*
   2  *  ZeX/OS
   3  *  Copyright (C) 2007  Tomas 'ZeXx86' Jedrzejek (zexx86@gmail.com)
   4  *  Copyright (C) 2008  Tomas 'ZeXx86' Jedrzejek (zexx86@gmail.com)
   5  *  Copyright (C) 2009  Tomas 'ZeXx86' Jedrzejek (zexx86@gmail.com)
   6  *
   7  *  This program is free software: you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation, either version 3 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21
  22 unsigned char getch ()
  23 {
  24         /*unsigned char *ret = 0;
  25
  26         asm volatile ("movl $2, %%eax;"
  27              "int $0x80;"
  28              "movl %%eax, %0" : "=g" (ret) :: "%eax");*/
  29
  30         asm volatile ("movl $2, %%eax;"
  31              "int $0x80;" ::: "%eax");
  32
  33         /* get return value */
  34         unsigned char *memptr = (unsigned char *) 0x905d;
  35         unsigned char ret = *memptr;
  36
  37         *memptr = 0;
  38
  39         return ret;
  40 }