Implemented IDT

But something's wrong with the GDT
Next up is a Serial Console

arch/i386/boot.s

@@ -53,3 +53,10 @@ gdt_flush:
 	ljmp *(%esp) #long jump
 flush2:
 	ret           #return to c code
+	
+.global idt_load
+.extern idtp
+idt_load:
+	lidt (idtp)
+	ret
+	

include/kernel/descriptor_tables.h

@@ -0,0 +1,7 @@
+#pragma once
+
+void gdt_set_gate(int, unsigned long, unsigned long, unsigned char, unsigned char);
+void gdt_install();
+
+void idt_set_gate(unsigned char, unsigned long, unsigned short, unsigned char);
+void idt_install();

include/kernel/idt.h

@@ -0,0 +1,19 @@
+#include <kernel/utils.h>
+
+struct idt_entry {
+	unsigned short base_low;
+	unsigned short selector;
+	unsigned char always0;
+	unsigned char flags;
+	unsigned short base_high;
+} __attribute__((packed));
+
+struct idt_ptr {
+	unsigned short limit;
+	unsigned int base;
+}__attribute__((packed));
+
+struct idt_entry idt[256]; //interrupt table of 256 entries
+struct idt_ptr idtp; //pointer to idt table
+
+extern void idt_load();

include/kernel/utils.h

@@ -9,3 +9,7 @@ size_t strlen(const char*);
 unsigned char inb(unsigned short);
 
 void outb(unsigned short, unsigned char);
+
+void memcpy(void*, void*, size_t);
+
+void memset(void*, int, size_t);

kernel/idt.c

@@ -0,0 +1,42 @@
+#include <kernel/utils.h>
+
+struct idt_entry {
+	unsigned short base_low;
+	unsigned short selector;
+	unsigned char always0;
+	unsigned char flags;
+	unsigned short base_high;
+} __attribute__((packed));
+
+struct idt_ptr {
+	unsigned short limit;
+	unsigned int base;
+}__attribute__((packed));
+
+struct idt_entry idt[256]; // Interrupt table of 256 entries
+struct idt_ptr idtp; // Pointer to idt table
+
+extern void idt_load();
+
+void idt_set_gate(unsigned char num, unsigned long base, unsigned short sel, unsigned char flags) {
+	idt[num].base_low = base & 0xFFFF;
+	idt[num].base_high = (base >> 16) & 0xFFFF;
+	
+	idt[num].selector = sel;
+	idt[num].always0 = 0;
+	
+	// Must be uncommented when we get to usermode - it sets the permission
+	// level to 3
+	idt[num].flags = flags; // | 0x60;
+}
+
+void idt_install() {
+	idtp.limit = (sizeof (struct idt_entry) * 256) - 1;
+	idtp.base = &idt;
+	
+	memset(&idt, 0, sizeof(struct idt_entry) * 256);
+	
+	// All ISRs go here
+	
+	idt_load();
+}

kernel/kernel.c

@@ -7,6 +7,8 @@
 int kernel_main(void) {
 	//Prepare the GDT
 	gdt_install();
+	//Prepare interrupts
+	//idt_install();
 	//Prepare the screen, and blank it out.
 	screen_initialize();
 	

kernel/utils.c

@@ -17,3 +17,19 @@ unsigned char inb(unsigned short port) {
 void outb(unsigned short port, unsigned char data) {
 	asm volatile("outb %1, %0" : : "dN" (port), "a" (data));
 }
+
+void memcpy(void* dest, void* src, size_t n) {
+	char* src_c  = (char*)src;
+	char* dest_c = (char*)dest;
+	
+	for(size_t i = 0; i < n; i++) {
+		dest_c[i] = src_c[i];
+	}
+}
+
+void memset(void* src, int chr, size_t n) {
+	unsigned char* ptr = src;
+	while(n--) {
+		*ptr++ = (unsigned char) chr;
+	}
+}

makefile

@@ -31,6 +31,7 @@ KERNEL_OBJS=           \
 $(KERNEL_ARCH_OBJS)    \
 kernel/utils.o         \
 kernel/gdt.o           \
+kernel/idt.o           \
 kernel/kernel.o        
 
 OBJS=\