And finally add IDT files (I suck at git)

Author: levex

arch/idt.c

@@ -0,0 +1,86 @@
+/** @author Levente Kurusa <[email protected]> **/
+#include <stdint.h>
+#include "../include/x86/idt.h"
+#include "../include/display.h"
+
+MODULE("IDT");
+
+static uint32_t idt_location = 0;
+static uint32_t idtr_location = 0;
+static uint16_t idt_size = 0x800;
+
+static uint8_t test_success = 0;
+static uint32_t test_timeout = 0x1000;
+
+void __idt_default_handler();
+void __idt_test_handler();
+
+void idt_init()
+{
+	idt_location = 0x402000;
+	mprint("Location: 0x%x\n", idt_location);
+	idtr_location = 0x401F00;
+	mprint("IDTR location: 0x%x\n", idtr_location);
+	for(uint8_t i = 0; i < 255; i++)
+	{
+		idt_register_interrupt(i, __idt_default_handler);
+	}
+	idt_register_interrupt(0x2f, __idt_test_handler);
+	mprint("Registered all interrupts to default handler.\n");
+	/* create IDTR now */
+	*(uint16_t*)idtr_location = idt_size - 1;
+	*(uint32_t*)(idtr_location + 2) = idt_location;
+	mprint("IDTR.size = 0x%x IDTR.offset = 0x%x\n", *(uint16_t*)idtr_location, *(uint32_t*)(idtr_location + 2));
+	_set_idtr();
+	mprint("IDTR set, testing link.\n");
+	asm volatile("int $0x2f");
+	while(test_timeout != 0)
+	{
+		if(test_success != 0)
+		{
+			mprint("Test succeeded, disabling INT#0x2F\n");
+			idt_register_interrupt(0x2F, __idt_default_handler);
+			break;
+		}
+	}
+	if(!test_success)
+		panic("Link test failed.");
+	return;
+}
+
+void __idt_test_handler()
+{
+	INT_START;
+	test_success = 1;
+	INT_END;
+}
+
+void __idt_default_handler()
+{
+	panic("Unhandled interrupt!\n");
+}
+
+void idt_register_interrupt(uint8_t i, void(*callback)())
+{
+	idt_descriptor desc = {0};
+	desc.offset_0_15 = (uint16_t)callback;
+	desc.selector = 0x8;
+	desc.zero = 0;
+	desc.type_attr = 0 | IDT_32BIT_INTERRUPT_GATE | IDT_DPL_3 | IDT_PRESENT;
+	desc.offset_16_31 = (uint16_t)((uint32_t)callback >> 16);
+	/*mprint("Descriptor: id%d offset 0x%x, orig 0x%x\n", 
+		i,
+		desc.offset_16_31 << 16 | desc.offset_0_15,
+		(uint32_t)callback);*/
+	add_idt_descriptor(i, desc);
+}
+
+void add_idt_descriptor(uint8_t id, idt_descriptor desc)
+{
+	*(uint16_t*)(idt_location + sizeof(idt_descriptor)*id + 0) = desc.offset_0_15;
+	*(uint16_t*)(idt_location + sizeof(idt_descriptor)*id + 2) = desc.selector;
+	*(uint8_t*) (idt_location + sizeof(idt_descriptor)*id + 4) = desc.zero;
+	*(uint8_t*) (idt_location + sizeof(idt_descriptor)*id + 5) = desc.type_attr;
+	*(uint16_t*)(idt_location + sizeof(idt_descriptor)*id + 6) = desc.offset_16_31;
+	return;
+}

include/x86/idt.h

@@ -0,0 +1,26 @@
+/** @author Levente Kurusa <[email protected]> **/
+#ifndef __IDT_H_
+#define __IDT_H_
+
+typedef struct {
+	uint16_t offset_0_15;
+	uint16_t selector;
+	uint8_t zero;
+	uint8_t type_attr;
+	uint16_t offset_16_31;
+} __attribute__((packed)) idt_descriptor;
+
+#define IDT_32BIT_INTERRUPT_GATE	0xE
+#define IDT_STORAGE_SEGMENT		0x20
+#define IDT_DPL_3			0x60
+#define IDT_PRESENT			0x80
+
+#define INT_START asm volatile("pusha");
+#define INT_END asm volatile("popa"); \
+	asm volatile("iret");
+
+extern void idt_init();
+extern void idt_register_interrupt(uint8_t i, void(*callback)());
+extern void add_idt_descriptor(uint8_t id, idt_descriptor desc);
+
+#endif