global loader

section .__mbHeader

align 0x4
section .text:

MAGIC_NUMBER      equ 0x1BADB002   ; multiboot magic 
FLAGS             equ 0x0 
CHECKSUM          equ -MAGIC_NUMBER
KERNEL_STACK_SIZE equ 4096

  dd MAGIC_NUMBER
  dd FLAGS
  dd CHECKSUM

extern kmain

loader:
  cli
  ; mov eax, 0xCAFEBABE
  push dword 42
  call kmain

.loop:
  jmp .loop

global gdt_flush
extern gp

gdt_flush:
	lgdt [gp]
	mov ax, 0x10
	mov ds, ax
	mov es, ax
	mov fs, ax
	mov gs, ax
	mov ss, ax
	jmp 0x08:flush2

flush2:
	ret

global idt_load
extern idtp

idt_load:
	lidt [idtp]
	ret

global isr0
global isr1
global isr2
global isr3
global isr4
global isr5
global isr6
global isr7
global isr8
global isr9
global isr10
global isr11
global isr12
global isr13
global isr14
global isr15
global isr16
global isr17
global isr18
global isr19
global isr20
global isr21
global isr22
global isr23
global isr24
global isr25
global isr26
global isr27
global isr28
global isr29
global isr30
global isr31

; Interrupt service routine exceptions
isr0:
	cli
	push byte 0
	push byte 0
	jmp isr_common_stub

isr1:
	cli
	push byte 0
	push byte 1
	jmp isr_common_stub

isr2:
	cli
	push byte 0
	push byte 2
	jmp isr_common_stub

isr3:
	cli
	push byte 0
	push byte 3
	jmp isr_common_stub

isr4:
	cli
	push byte 0
	push byte 4
	jmp isr_common_stub

isr5:
	cli
	push byte 0
	push byte 5
	jmp isr_common_stub

isr6:
	cli
	push byte 0
	push byte 6
	jmp isr_common_stub

isr7:
	cli
	push byte 0
	push byte 7
	jmp isr_common_stub

isr8:
	cli
	push byte 8
	jmp isr_common_stub

isr9:
	cli
	push byte 0
	push byte 9
	jmp isr_common_stub

isr10:
	cli
	push byte 10
	jmp isr_common_stub

isr11:
	cli
	push byte 11
	jmp isr_common_stub

isr12:
	cli
	push byte 12
	jmp isr_common_stub

isr13:
	cli
	push byte 13
	jmp isr_common_stub

isr14:
	cli
	push byte 14
	jmp isr_common_stub

isr15:
	cli
	push byte 0
	push byte 15
	jmp isr_common_stub

isr16:
	cli
	push byte 0
	push byte 16
	jmp isr_common_stub

isr17:
	cli
	push byte 0
	push byte 17
	jmp isr_common_stub

isr18:
	cli
	push byte 0
	push byte 18
	jmp isr_common_stub

isr19:
	cli
	push byte 0
	push byte 19
	jmp isr_common_stub

isr20:
	cli
	push byte 0
	push byte 20
	jmp isr_common_stub

isr21:
	cli
	push byte 0
	push byte 21
	jmp isr_common_stub

isr22:
	cli
	push byte 0
	push byte 22
	jmp isr_common_stub

isr23:
	cli
	push byte 0
	push byte 23
	jmp isr_common_stub

isr24:
	cli
	push byte 0
	push byte 24
	jmp isr_common_stub

isr25:
	cli
	push byte 0
	push byte 25
	jmp isr_common_stub

isr26:
	cli
	push byte 0
	push byte 26
	jmp isr_common_stub

isr27:
	cli
	push byte 0
	push byte 27
	jmp isr_common_stub

isr28:
	cli
	push byte 0
	push byte 28
	jmp isr_common_stub

isr29:
	cli
	push byte 0
	push byte 29
	jmp isr_common_stub

isr30:
	cli
	push byte 0
	push byte 30
	jmp isr_common_stub

isr31:
	cli
	push byte 0
	push byte 31
	jmp isr_common_stub

extern fault_handler

isr_common_stub:
	pusha
	push ds
	push es
	push fs
	push gs
	mov ax, 0x10
	mov ds, ax
	mov es, ax
	mov fs, ax
	mov gs, ax
	mov eax, esp
	push eax
	mov eax, fault_handler
	call eax
	pop eax
	pop gs
	pop fs
	pop es
	pop ds
	popa
	add esp, 8
	iret

global irq0
global irq1
global irq2
global irq3
global irq4
global irq5
global irq6
global irq7
global irq8
global irq9
global irq10
global irq11
global irq12
global irq13
global irq14
global irq15

irq0:
	cli
	push byte 0
	push byte 32
	jmp irq_common_stub

irq1:
	cli
	push byte 0
	push byte 33
	jmp irq_common_stub

irq2:
	cli
	push byte 0
	push byte 34
	jmp irq_common_stub

irq3:
	cli
	push byte 0
	push byte 35
	jmp irq_common_stub

irq4:
	cli
	push byte 0
	push byte 36
	jmp irq_common_stub

irq5:
	cli
	push byte 0
	push byte 37
	jmp irq_common_stub

irq6:
	cli
	push byte 0
	push byte 38
	jmp irq_common_stub

irq7:
	cli
	push byte 0
	push byte 39
	jmp irq_common_stub

irq8:
	cli
	push byte 0
	push byte 40
	jmp irq_common_stub

irq9:
	cli
	push byte 0
	push byte 41
	jmp irq_common_stub

irq10:
	cli
	push byte 0
	push byte 42
	jmp irq_common_stub

irq11:
	cli
	push byte 0
	push byte 43
	jmp irq_common_stub

irq12:
	cli
	push byte 0
	push byte 44
	jmp irq_common_stub

irq13:
	cli
	push byte 0
	push byte 45
	jmp irq_common_stub

irq14:
	cli
	push byte 0
	push byte 46
	jmp irq_common_stub

irq15:
	cli
	push byte 0
	push byte 47
	jmp irq_common_stub

extern irq_handler

irq_common_stub:
	pusha
	push ds
	push es
	push fs
	push gs
	mov ax, 0x10
	mov ds, ax
	mov es, ax
	mov fs, ax
	mov gs, ax
	mov eax, esp
	push eax
	mov eax, irq_handler
	call eax
	pop eax
	pop gs
	pop fs
	pop es
	pop ds
	popa
	add esp, 8
	iret

section .bss
align 4 
kernel_stack:
  resb KERNEL_STACK_SIZE
  mov esp, kernel_stack + KERNEL_STACK_SIZE