APIC timer driver

src/kernel/arch/i686/isr.c

@@ -57,6 +57,14 @@ void i686_isr_initialize(){
 void __attribute__((cdecl)) i686_isr_handler(registers *regs){
     if(g_isr_handlers[regs->interrupt] != NULL){
         g_isr_handlers[regs->interrupt](regs);
+
+        // Send EOI to PIC if necessary
+        if(regs->interrupt >= PIC1_VEC_OFFSET && regs->interrupt < PIC1_VEC_OFFSET+8){
+            i686_outb(PIC1_CMD_PORT, PIC_EOI);
+        }
+        else if(regs->interrupt >= PIC2_VEC_OFFSET && regs->interrupt < PIC2_VEC_OFFSET+8){
+            i686_outb(PIC2_CMD_PORT, PIC_EOI);
+        }
     }
     else if(regs->interrupt >= 32){
         printf("Unhandled interrupt %i\n", regs->interrupt);

src/kernel/arch/i686/pic.c

@@ -14,8 +14,8 @@ void i686_pic_initialize(){
     i686_outb(PIC2_CMD_PORT, 0x11); // PIC2
 
     // ICW2: Remap IRQs
-    i686_outb(PIC1_DATA_PORT, 0x20); // PIC1 remapped to 0x20 (32)
-    i686_outb(PIC2_DATA_PORT, 0x28); // PIC2 remapped to 0x28 (40)
+    i686_outb(PIC1_DATA_PORT, PIC1_VEC_OFFSET); // PIC1 remapped to PIC1_VEC_OFFSET
+    i686_outb(PIC2_DATA_PORT, PIC2_VEC_OFFSET); // PIC2 remapped to PIC2_VEC_OFFSET
 
     // ICW3: Cascade settings
     i686_outb(PIC1_DATA_PORT, 0x04); // PIC1 is told that slave PIC is at IRQ2

src/kernel/arch/i686/pic.h

@@ -5,4 +5,9 @@
 #define PIC2_CMD_PORT 0xA0
 #define PIC2_DATA_PORT 0xA1
 
+#define PIC1_VEC_OFFSET 0x20
+#define PIC2_VEC_OFFSET 0x28
+
+#define PIC_EOI 0x20
+
 void i686_pic_initialize();

src/kernel/drivers/timer.c

@@ -0,0 +1,11 @@
+#include "timer.h"
+#include "../arch/i686/isr.h"
+#include "../stdio.h"
+
+static void timer_handler(registers *regs){
+    printf("TICK\n");
+}
+
+void timer_initialize(){
+    i686_isr_register_handler(IRQ(0), timer_handler);
+}

src/kernel/drivers/timer.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void timer_initialize();

src/kernel/main.c

@@ -1,13 +1,14 @@
 #include <stdint.h>
 #include "stdio.h"
 #include "hal/hal.h"
+#include "drivers/timer.h"
 
 void __attribute__((cdecl)) kmain(uint64_t magic, uint64_t addr){
     hal_initialize();
+    timer_initialize();
     
     puts("\x1b[33mWARNING\x1b[0m");
     printf(": amazing %s ahead!\n", "math");
     printf("%i+%i=%i\n", 1, 1, 2);
-    printf("0/0=%i", 0/0);
     for(;;);
 }