ISRs assembly code

global isr0
; rest of the globals go here
global isr31

extern fault_handler

; Divide By Zero Exception

isr0:
    cli
    push byte 0             ; a normal ISR stub that pushes a dummy error code to keep a uniform stack frame
    push byte 0
    jmp isr_common_stub

; rest of the ISRs go here

; Reserved

isr31:
    cli
    push byte 0
    push byte 31
    jmp isr_common_stub

isr_common_stub:
    pusha
    push ds
    push es
    push fs
    push gs
    mov ax, 0x10            ; load the kernel data segment descriptor
    mov ds, ax
    mov es, ax
    mov fs, ax
    mov gs, ax
    push eax
    call fault_handler
    pop eax
    pop gs
    pop fs
    pop es
    pop ds
    popa
    add esp, 8              ; cleans up the pushed error code and ISR number
    iret                    ; pop CS, EIP, EFLAGS, SS, ESP