caos-with-snake/port.h

#pragma once

static unsigned char port_byte_in(unsigned short port) {
    unsigned char result;
    __asm__("in %%dx, %%al" : "=a" (result) : "d" (port));
    return result;
}

static unsigned short port_word_in(unsigned short port) {
    unsigned short result;
    __asm__("in %%dx, %%ax" : "=a" (result) : "d" (port));
    return result;
}

static void port_byte_out(unsigned short port, unsigned char data) {
    __asm__("outb %%al, %%dx" : : "a" (data), "d" (port));
}

static void port_word_out(unsigned short port, unsigned short data) {
    __asm__("outw %%ax, %%dx" : : "a" (data), "d" (port));
}

static void port_long_out(unsigned short port, unsigned int data) {
    __asm__("outl %%eax, %%dx" : : "a" (data), "d" (port));
}