io.c

一个用于学习的操作系统

#include <fairysky/types.h>



void outb(char value, u16 port)
{
    __asm__ __volatile__ ("outb %0, %1"
        ::"a" ((char) value), "d" ((u16) port));
}

void outw(u16 value, u16 port)
{
    __asm__ __volatile__ ("outw %0, %1"
        ::"a" ((u16) value), "d" ((u16) port));
}

void outb_p(char value, u16 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" ((u16) port));
}

u8 inb(u16 port)
{
    u8 _v;
    __asm__ __volatile__ ("inb %1,%0"
        :"=a" (_v)
        :"d" ((unsigned short) port));
    return _v;
}

u16 inw(u16 port)
{
    u16 _v;
    __asm__ __volatile__ ("inb %1,%0"
        :"=a" (_v)
        :"d" ((unsigned short) port));
    return _v;
}

u8 inb_p(u16 port)
{
    u8 _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" ((u16) port));
    return _v;
}