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#include <io.h>
#include <arch/i386/pic.h>
#include <stdint.h>
#include <arch/i386/pic.h>
#define PIC1 0x20
#define PIC2 0xA0
#define PIC1_CMD PIC1
#define PIC1_DATA (PIC1 + 1)
#define PIC2_CMD PIC2
#define PIC2_DATA (PIC2 + 1)
#define PIC_READ_IRR 0x0a // OCW3 irq ready next CMD read
#define PIC_READ_ISR 0x0b // OCW3 irq service next CMD read
#define PIC_EOI 0x20
// pic reinitialization constants
#define ICW1_ICW4 0x01 // indicates icw4 will be present
#define ICW1_SINGLE 0x02 // single cascade mode
#define ICW1_INTERVAL4 0x04 // call address interval 4
#define ICW1_LEVEL 0x08 // level triggered (edge) mode
#define ICW1_INIT 0x10 // initialization
#define ICW4_8086 0x01 // 8086 mode
#define ICW4_AUTO 0x02 // auto (normal) eoi
#define ICW4_BUF_SLAVE 0x08 // buffered mode/slave
#define ICW4_BUF_MASTER 0x0C // buffered mode/master
#define ICW4_SFNM 0x10 // special fully nested (not)
void pic_send_eoi(unsigned char irq) {
if (irq >= 8) {
outb(PIC2_CMD, PIC_EOI);
}
outb(PIC1_CMD, PIC_EOI);
}
// offset 1 is for master, offset 2 is for slave
void pic_remap(int offset1, int offset2) {
unsigned char a1, a2;
a1 = inb(PIC1_DATA); // save masks
a2 = inb(PIC2_DATA);
outb(PIC1_CMD, ICW1_INIT | ICW1_ICW4); // starts initialization in cascade mode
io_wait();
outb(PIC2_CMD, ICW1_INIT | ICW1_ICW4);
io_wait();
outb(PIC1_DATA, offset1); // icw2: master and slave vector offset set
io_wait();
outb(PIC2_DATA, offset2);
io_wait();
outb(PIC1_DATA, 4); // tells master pic theres a slave pic at irq2
io_wait();
outb(PIC2_DATA, 2); // tells slave pic its cascade identity
io_wait();
outb(PIC1_DATA, ICW4_8086);
io_wait();
outb(PIC2_DATA, ICW4_8086);
io_wait();
outb(PIC1_DATA, a1); // restore masks
outb(PIC2_DATA, a2);
for (char i = 0; i < 15; i++)
{
irq_set_mask(i);
}
}
void irq_set_mask(unsigned char irq) {
uint16_t port;
uint8_t value;
if (irq < 8) {
port = PIC1_DATA;
} else {
port = PIC2_DATA;
irq -= 8;
}
value = inb(port) | (1 << irq);
outb(port, value);
}
void irq_clear_mask(unsigned char irq) {
uint16_t port;
uint8_t value;
if (irq < 8) {
port = PIC1_DATA;
} else {
port = PIC2_DATA;
irq -= 8;
}
value = inb(port) & ~(1 << irq);
outb(port, value);
}
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