[GLOBAL idt_flush]

idt_flush:
  mov eax, [esp + 4]
  lidt [eax]
  ret

; **********************************************************

; stuff for handling interrupts
[EXTERN interrupt_handler]

%macro ISR_NOERRCODE 1
  [GLOBAL isr%1]
  isr%1:
    cli
    push byte 0
    push byte %1
    jmp interrupt_common_stub
%endmacro

%macro ISR_ERRCODE 1
  [GLOBAL isr%1]
  isr%1:
    cli
    push byte %1
    jmp interrupt_common_stub
%endmacro

%macro IRQ 2
  [GLOBAL irq%1]
  irq%1:
    cli
    push byte 0
    push byte %2
    jmp interrupt_common_stub
%endmacro

%macro SYSCALL 1
  [GLOBAL int%1]
  int%1:
    cli
    push byte 0
    push byte %1
    jmp interrupt_common_stub
%endmacro

; ********************************************************************

ISR_NOERRCODE 0
ISR_NOERRCODE 1
ISR_NOERRCODE 2
ISR_NOERRCODE 3
ISR_NOERRCODE 4
ISR_NOERRCODE 5
ISR_NOERRCODE 6
ISR_NOERRCODE 7
ISR_ERRCODE 8
ISR_NOERRCODE 9
ISR_ERRCODE 10
ISR_ERRCODE 11
ISR_ERRCODE 12
ISR_ERRCODE 13
ISR_ERRCODE 14
ISR_NOERRCODE 15
ISR_NOERRCODE 16
ISR_NOERRCODE 17
ISR_NOERRCODE 18
ISR_NOERRCODE 19
ISR_NOERRCODE 20
ISR_NOERRCODE 21
ISR_NOERRCODE 22
ISR_NOERRCODE 23
ISR_NOERRCODE 24
ISR_NOERRCODE 25
ISR_NOERRCODE 26
ISR_NOERRCODE 27
ISR_NOERRCODE 28
ISR_NOERRCODE 29
ISR_NOERRCODE 30
ISR_NOERRCODE 31

IRQ	0,	32
IRQ	1,	33
IRQ	2,	34
IRQ	3,	35
IRQ	4,	36
IRQ	5,	37
IRQ	6,	38
IRQ	7,	39
IRQ	8,	40
IRQ	9,	41
IRQ	10,	42
IRQ	11,	43
IRQ	12,	44
IRQ	13,	45
IRQ	14,	46
IRQ	15,	47

SYSCALL 64  ; this syscall is the one and only useful syscall. It does everything.
; The next syscalls are task-managing-specific
SYSCALL 65	; this syscall requests a task switch
SYSCALL 66  ; signals to kernel that thread has finished (retval in eax)

; ******************************************************************

interrupt_common_stub:
   pusha                    ; Pushes edi,esi,ebp,esp,ebx,edx,ecx,eax

   mov ax, ds               ; Lower 16-bits of eax = ds.
   push eax                 ; save the data segment descriptor

   mov ax, 0x10  ; load the kernel data segment descriptor
   mov ds, ax
   mov es, ax
   mov fs, ax
   mov gs, ax

   call interrupt_handler

   pop eax        ; reload the original data segment descriptor
   mov ds, ax
   mov es, ax
   mov fs, ax
   mov gs, ax

   popa                     ; Pops edi,esi,ebp...
   add esp, 8     ; Cleans up the pushed error code and pushed ISR number
   sti
   iret