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idt.asm
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isr_0:
cli
push 0
jmp isr_basic
isr_1:
cli
push 1
jmp isr_basic
isr_2:
cli
push 2
jmp isr_basic
isr_3:
cli
push 3
jmp isr_basic
isr_4:
cli
push 4
jmp isr_basic
isr_5:
cli
push 5
jmp isr_basic
isr_6:
cli
push 6
jmp isr_basic
isr_7:
cli
push 7
jmp isr_basic
isr_8:
cli
push 8
jmp isr_basic
isr_9:
cli
push 9
jmp isr_basic
isr_10:
cli
push 10
jmp isr_basic
isr_11:
cli
push 11
jmp isr_basic
isr_12:
cli
push 12
jmp isr_basic
isr_13:
cli
push 13
jmp isr_basic
isr_14:
cli
push 14
jmp isr_basic
isr_15:
cli
push 15
jmp isr_basic
isr_16:
cli
push 16
jmp isr_basic
isr_17:
cli
push 17
jmp isr_basic
isr_18:
cli
push 18
jmp isr_basic
isr_19:
cli
push 19
jmp isr_basic
isr_20:
cli
push 20
jmp isr_basic
isr_21:
cli
push 21
jmp isr_basic
isr_22:
cli
push 22
jmp isr_basic
isr_23:
cli
push 23
jmp isr_basic
isr_24:
cli
push 24
jmp isr_basic
isr_25:
cli
push 25
jmp isr_basic
isr_26:
cli
push 26
jmp isr_basic
isr_27:
cli
push 27
jmp isr_basic
isr_28:
cli
push 28
jmp isr_basic
isr_29:
cli
push 29
jmp isr_basic
isr_30:
cli
push 30
jmp isr_basic
isr_31:
cli
push 31
jmp isr_basic
isr_32:
cli
pusha ; this instruction pushes the values of the general-purpose registers onto the stack
mov eax, [esp + 32] ; getting the value of EIP (return address of the suspended process)
push eax
call scheduler ; calling the scheduler we wrote in C
mov al, 0x20
out 0x20, al
add esp, 40d ; telling PIC that IRQ was handled
push run_next_process
iret
isr_33:
cli
push 33
jmp irq_basic
isr_34:
cli
push 34
jmp irq_basic
isr_35:
cli
push 35
jmp irq_basic
isr_36:
cli
push 36
jmp irq_basic
isr_37:
cli
push 37
jmp irq_basic
isr_38:
cli
push 38
jmp irq_basic
isr_39:
cli
push 39
jmp irq_basic
isr_40:
cli
push 40
jmp irq_basic
isr_41:
cli
push 41
jmp irq_basic
isr_42:
cli
push 42
jmp irq_basic
isr_43:
cli
push 43
jmp irq_basic
isr_44:
cli
push 44
jmp irq_basic
isr_45:
cli
push 45
jmp irq_basic
isr_46:
cli
push 46
jmp irq_basic
isr_47:
cli
push 47
jmp irq_basic
isr_48:
cli
push 48
jmp irq_basic
isr_basic:
call interrupt_handler
pop eax
sti
iret ; short for interrupt return
irq_basic:
call interrupt_handler
mov al, 0x20 ; EOI (End Of Interrupt)
out 0x20, al
cmp byte [esp], 40d
jnge irq_basic_end
mov al, 0xa0
out 0x20, al
irq_basic_end:
pop eax
sti
iret
idt:
; Value of fields are as follows:
; 1- Handler's Name
; 2- Segment Selector
; 3- Present
; 4- Privelege Level
; 5- Descriptor Size
; 6- Gate type
dw isr_0, 8, 0x8e00, 0x0000
dw isr_1, 8, 0x8e00, 0x0000
dw isr_2, 8, 0x8e00, 0x0000
dw isr_3, 8, 0x8e00, 0x0000
dw isr_4, 8, 0x8e00, 0x0000
dw isr_5, 8, 0x8e00, 0x0000
dw isr_6, 8, 0x8e00, 0x0000
dw isr_7, 8, 0x8e00, 0x0000
dw isr_8, 8, 0x8e00, 0x0000
dw isr_9, 8, 0x8e00, 0x0000
dw isr_10, 8, 0x8e00, 0x0000
dw isr_11, 8, 0x8e00, 0x0000
dw isr_12, 8, 0x8e00, 0x0000
dw isr_13, 8, 0x8e00, 0x0000
dw isr_14, 8, 0x8e00, 0x0000
dw isr_15, 8, 0x8e00, 0x0000
dw isr_16, 8, 0x8e00, 0x0000
dw isr_17, 8, 0x8e00, 0x0000
dw isr_18, 8, 0x8e00, 0x0000
dw isr_19, 8, 0x8e00, 0x0000
dw isr_20, 8, 0x8e00, 0x0000
dw isr_21, 8, 0x8e00, 0x0000
dw isr_22, 8, 0x8e00, 0x0000
dw isr_23, 8, 0x8e00, 0x0000
dw isr_24, 8, 0x8e00, 0x0000
dw isr_25, 8, 0x8e00, 0x0000
dw isr_26, 8, 0x8e00, 0x0000
dw isr_27, 8, 0x8e00, 0x0000
dw isr_28, 8, 0x8e00, 0x0000
dw isr_29, 8, 0x8e00, 0x0000
dw isr_30, 8, 0x8e00, 0x0000
dw isr_31, 8, 0x8e00, 0x0000
dw isr_32, 8, 0x8e00, 0x0000
dw isr_33, 8, 0x8e00, 0x0000
dw isr_34, 8, 0x8e00, 0x0000
dw isr_35, 8, 0x8e00, 0x0000
dw isr_36, 8, 0x8e00, 0x0000
dw isr_37, 8, 0x8e00, 0x0000
dw isr_38, 8, 0x8e00, 0x0000
dw isr_39, 8, 0x8e00, 0x0000
dw isr_40, 8, 0x8e00, 0x0000
dw isr_41, 8, 0x8e00, 0x0000
dw isr_42, 8, 0x8e00, 0x0000
dw isr_43, 8, 0x8e00, 0x0000
dw isr_44, 8, 0x8e00, 0x0000
dw isr_45, 8, 0x8e00, 0x0000
dw isr_46, 8, 0x8e00, 0x0000
dw isr_47, 8, 0x8e00, 0x0000
dw isr_48, 8, 0x8e00, 0x0000
idtr:
idt_size_in_bytes : dw idtr - idt
idt_base_address : dd idt