; Dispatching to our interrupt handler code from assembly because some of this is 
; enourmous pain in C

; Save the register state
; call the C handler
; executes iret(expects the stack to look like struct stack_state)


; If the interrupt we need to handle doesn't produce an error code then must provide a 0
; for consistency

extern interrupt_handler
extern cpu_reg_state
extern stack_state
extern idt_ptr

global load_idt
load_idt:
	lidt [idt_ptr]
	ret

%macro irq_handler 2
global irq_handler_%1
irq_handler_%1:
	push dword 0
	push dword %2
	jmp common_irq_handler
%endmacro

%macro no_err_handler 1
global no_err_handler_%1 	; defined in interrupts.h
no_err_handler_%1:
	push dword 0
	push dword %1
	jmp common_int_handler
%endmacro

; deals with the intterrupts that do give us an error code
%macro err_code_handler 1
global err_code_handler_%1
err_code_handler_%1:
	push dword %1
	jmp common_int_handler
%endmacro

extern interrupt_handler ; external handler (interrupts.c)
common_int_handler:
	; save thigns before do our C-call
	pushad
	;push eax ecx edx ebx
	;push esp ebp esi edi

	push ds
	push es 
	push fs 
	push gs

	; load the kernel segment descriptor
	mov ax, 0x10
	mov ds, ax
	mov es, ax
	mov fs, ax
	mov gs, ax
	mov eax, esp	; pushing the stack into the next call
	push eax
	mov eax, interrupt_handler
	call eax 		; preserve the eip register past this call

	; segments
	pop eax
	pop gs 
	pop fs
	pop es
	pop ds

	popad

	add esp, 8
	; special instruction which lets us jump back to code
	; which was previously interrupted
	iret 	


no_err_handler 0
no_err_handler 1
no_err_handler 2
no_err_handler 3
no_err_handler 4
no_err_handler 5
no_err_handler 6
no_err_handler 7

err_code_handler 8

no_err_handler 9

err_code_handler 10
err_code_handler 11
err_code_handler 12
err_code_handler 13
err_code_handler 14

no_err_handler 15
no_err_handler 16
no_err_handler 17
no_err_handler 18
no_err_handler 19
no_err_handler 20
no_err_handler 21
no_err_handler 22
no_err_handler 23
no_err_handler 24
no_err_handler 25
no_err_handler 26
no_err_handler 27
no_err_handler 28
no_err_handler 29
no_err_handler 30
no_err_handler 31


common_irq_handler:
	ret

; Remapped IRQ's for the APIC

# starting from irq 0 -> 15 but remapped to 32 -> 47
irq_handler 0, 32
irq_handler 1, 33
irq_handler 2, 34
irq_handler 3, 35
irq_handler 4, 36
irq_handler 5, 37
irq_handler 6, 38
irq_handler 7, 39
irq_handler 8, 40
irq_handler 9, 41
irq_handler 10, 42
irq_handler 11, 43
irq_handler 12, 44
irq_handler 13, 45
irq_handler 14, 46
irq_handler 15, 47