io.h

来自「fairysky系统,是一个小型的内核,模拟linux原始版本的」· C头文件 代码 · 共 55 行

/*文件名: io.h
  说明:   提供io操作的函数
  作者:   marsinfan
  日期:   2005/12/05
*/

#ifndef _ASM_IO_H
#define _ASM_IO_H

extern void inline outb(char value, unsigned short port)
{
    __asm__ __volatile__ ("outb %0,%1"
        ::"a" ((char) value), "d" ((unsigned short) port));
}

extern void inline outb_p(char value, unsigned short port)
{
    __asm__ __volatile__ ("outb %0,%1\n\t"
#ifdef REALLY_SLOW_IO
          "outb %0,$0x80\n\t"
          "outb %0,$0x80\n\t"
          "outb %0,$0x80\n\t"
#endif
          "outb %0,$0x80"
        ::"a" ((char) value),"d" ((unsigned short) port));
}

extern unsigned char inline inb(unsigned short port)
{
    unsigned char _v;
    __asm__ __volatile__ ("inb %1,%0"
        :"=a" (_v)
        :"d" ((unsigned short) port));
    return _v;
}

extern unsigned char inline inb_p(unsigned short port)
{
    unsigned char _v;
__asm__ __volatile__ ("inb %1, %0\n\t"
#ifdef REALLY_SLOW_IO
          "outb %0,$0x80\n\t"
          "outb %0,$0x80\n\t"
          "outb %0,$0x80\n\t"
#endif
          "outb %0,$0x80"
        :"=a" (_v)
        :"d" ((unsigned short) port));
    return _v;
}


#endif