#include void PIC_remap() { unsigned char a1, a2; a1 = inb(PIC1_DATA); // save masks a2 = inb(PIC2_DATA); outb(PIC1_COMMAND, ICW1_INIT | ICW1_ICW4); // Start init sequence in cascade mode io_wait(); outb(PIC2_COMMAND, ICW1_INIT | ICW1_ICW4); io_wait(); outb(PIC1_DATA, PIC1_OFFSET); // ICW2: Master PIC vector offset io_wait(); outb(PIC2_DATA, PIC2_OFFSET); // ICW2: Slave PIC vector offset io_wait(); outb(PIC1_DATA, 4); // ICW3: tell Master PIC that theres a slave PIC at IRQ2 (0000 0100) io_wait(); outb(PIC2_DATA, 2); // ICW3: tell Slave PIC its cascade identity (0000 0010) io_wait(); outb(PIC1_DATA, ICW4_8086); io_wait(); outb(PIC2_DATA, ICW4_8086); io_wait(); outb(PIC1_DATA, a1); // restore saved masks outb(PIC2_DATA, a2); }