YoutubeOS/IO.cpp at master · omarbackup/YoutubeOS · GitHub

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#pragma once
#include "Typedefs.cpp"

#define PIC1_COMMAND 0x20
#define PIC1_DATA 0x21
#define PIC2_COMMAND 0xA0
#define PIC2_DATA 0xA1

#define ICW1_INIT 0x10
#define ICW1_ICW4 0x01
#define ICW4_8086 0x01

void outb(unsigned short port, unsigned char val){
  asm volatile ("outb %0, %1" : : "a"(val), "Nd"(port));
}

unsigned char inb(unsigned short port){
  unsigned char returnVal;
  asm volatile ("inb %1, %0"
  : "=a"(returnVal)
  : "Nd"(port));
  return returnVal;
}

void RemapPic(){
  uint_8 a1, a2;

  a1 = inb(PIC1_DATA);
  a2 = inb(PIC2_DATA);

  outb(PIC1_COMMAND, ICW1_INIT | ICW1_ICW4);
  outb(PIC2_COMMAND, ICW1_INIT | ICW1_ICW4);
  outb(PIC1_DATA, 0);
  outb(PIC2_DATA, 8);
  outb(PIC1_DATA, 4);
  outb(PIC2_DATA, 2);
  outb(PIC1_DATA, ICW4_8086);
  outb(PIC2_DATA, ICW4_8086);

  outb(PIC1_DATA, a1);
  outb(PIC2_DATA, a2);

}