io.h

一个操作系统的源代码

/** io.h
 **
 ** Original Author: Kasper Verdich Lund
 ** Date: 10/11/99
 **
 ** Description:
 ** Low-level fnctions
 **
 ** 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; either version
 ** 2 of the License, or (at your option) any later version.
 **
 ** This program is distributed in the hope that it will be
 ** useful, but WITHOUT ANY WARRANTY; without even the implied
 ** warranty or MERCHANTABILITY or FITNESS FOR A PARTICULAR
 ** PURPOSE.  See the GNU General Public License for more
 ** details.
 **
 ** You should have received a copy of the GNU General Public
 ** License along with this program; if not, write to the
 ** Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 ** Boston, MA 02111-1307 USA
 **
 *********************************************************Apostle OS**/

#ifndef __IO_H_
#define __IO_H_

#include <types.h>

/* this code should be rewritten - it's messy  and ugly */
/* any better now? */

#define io_wait()   inb(0x80)

static inline byte inb (word port)
{
  register byte x;
  __asm__ __volatile__ (
    "inb %%dx,%%al"
    : "=a" (x)
    : "d" (port));
  return (x);
}

static inline word inw (word port)
{
  register word x;
  __asm__ __volatile__ (
    "inw %%dx,%%ax"
    : "=a" (x)
    : "d" (port));
  return (x);
}

static inline dword inl (word port)
{
  register dword x;
  __asm__ __volatile__ (
    "inl %%dx,%%eax"
    : "=a" (x)
    : "d" (port));
  return (x);
}

static inline void outb (word port, byte value)
{
  __asm__ __volatile__ (
    "outb %%al,%%dx"
    : /* no outputs */
    : "a" (value), "d" (port));
}

static inline void outw (word port, word value)
{
  __asm__ __volatile__ (
    "outw %%ax,%%dx"
    : /* no outputs*/
    : "a" (value), "d" (port));
}

static inline void outl (word port, dword value)
{
  __asm__ __volatile__ (
    "outl %%eax,%%dx"
    : /* no outputs */
    : "a" (value), "d" (port));
}

static inline void repinsw (port, buffer, count)
{
  __asm__ __volatile__ (
    "rep; insw"
    : /* no outputs */
    : "d" (port), "D" (buffer), "c" (count)
    : "eax", "ecx", "edx", "edi");
}

#endif /* __IO_H_ */