/
interrupt.S
executable file
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interrupt.S
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;
; interrupt.s -- Contains interrupt service routine wrappers.
; Based on Bran's kernel development tutorials.
; Rewritten for JamesM's kernel development tutorials.
%define KSEG 0x10
; Trace macros, use like trace 'i' to print char to serial port.
%macro io_outb 2
mov dx, %1 ; param1 = address, param2 = data.
mov al, %2
out dx, al
%endmacro
%macro trace 1
io_outb 0x3f8, %1 ; diagnostic character
%endmacro
; This macro creates a stub for an ISR which does NOT pass it's own
; error code (adds a dummy errcode byte).
%macro ISR_NOERRCODE 1
global isr%1
isr%1:
cli ; Disable interrupts firstly.
push byte 0 ; Push a dummy error code.
push byte %1 ; Push the interrupt number.
jmp isr_common_stub ; Go to our common handler code.
%endmacro
; This macro creates a stub for an ISR which passes it's own
; error code.
%macro ISR_ERRCODE 1
global isr%1
isr%1:
cli ; Disable interrupts.
push byte %1 ; Push the interrupt number
jmp isr_common_stub
%endmacro
; This macro creates a stub for an IRQ - the first parameter is
; the IRQ number, the second is the ISR number it is remapped to.
%macro IRQ 2
global irq%1
irq%1:
cli
push byte 0
push byte %2
jmp irq_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
; In isr.c
extern isr_handler
; This is our common ISR stub. It saves the processor state, sets
; up for kernel mode segments, calls the C-level fault handler,
; and finally restores the stack frame.
isr_common_stub:
; trace 'i'
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, KSEG ; load the kernel data segment descriptor
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
call isr_handler
pop ebx ; reload the original data segment descriptor
mov ds, bx
mov es, bx
mov fs, bx
mov gs, bx
popa ; Pops edi,esi,ebp...
add esp, 8 ; Cleans up the pushed error code and pushed ISR number
sti
iret ; pops 5 things at once: CS, EIP, EFLAGS, SS, and ESP
; In isr.c
extern irq_handler
; This is our common IRQ stub. It saves the processor state, sets
; up for kernel mode segments, calls the C-level fault handler,
; and finally restores the stack frame.
irq_common_stub:
; trace 'r'
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, KSEG ; load the kernel data segment descriptor
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
call irq_handler
pop ebx ; reload the original data segment descriptor
mov ds, bx
mov es, bx
mov fs, bx
mov gs, bx
popa ; Pops edi,esi,ebp...
add esp, 8 ; Cleans up the pushed error code and pushed ISR number
sti
iret ; pops 5 things at once: CS, EIP, EFLAGS, SS, and ESP