User:Johnburger/Demo/Ints/IRQs

Like Vectors, this code is merely the entry points for each of the Interrupt ReQuest handlers. They all perform the same steps:

• PUSH a pseudo-fault code onto the stack, to make the stack Frame the same for the Fault handler;
• PUSH the Interrupt number onto the stack;
• JMP to a routine to acknowledge the PIC(s);
• JMP to the default Fault handler to display the registers.

One of the steps that the Protected Mode initialisation does is to register new handlers for the Timer and Keyboard, replacing these default ones.

Demo/Ints/IRQs.inc

;
; Ints/IRQs.inc
;

; This file holds the entry points for all of the Interrupt ReQuests (IRQs).
; They all jump to the same handler, but not before saving away the number
; of the interrupt - oh, and a fault code since these should not happen!

; To save space, the handler has been put in the middle of the vectors, to
; allow the assembler to use shorter JMPs.
Ints.IRQ0:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    32      ; Interrupt number
                JMP             Ints.PIC.A
Ints.IRQ1:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    33      ; Interrupt number
                JMP             Ints.PIC.A
Ints.IRQ2:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    34      ; Interrupt number
                JMP             Ints.PIC.A
Ints.IRQ3:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    35      ; Interrupt number
                JMP             Ints.PIC.A
Ints.IRQ4:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    36      ; Interrupt number
                JMP             Ints.PIC.A
Ints.IRQ5:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    37      ; Interrupt number
                JMP             Ints.PIC.A
Ints.IRQ6:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    38      ; Interrupt number
                JMP             Ints.PIC.A
Ints.IRQ7:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    39      ; Interrupt number
                JMP             Ints.PIC.A

; Acknowledge Slave PIC (first)
Ints.PIC.B:
                PUSH            EAX
                MOV             AL,Dev.PIC.Cmd.EOI
                OUT             Dev.PIC.B.Cmd,AL
                POP             EAX
; Acknowledge Master PIC
Ints.PIC.A:
                PUSH            EAX
                MOV             AL,Dev.PIC.Cmd.EOI
                OUT             Dev.PIC.A.Cmd,AL
                POP             EAX
; All IRQs jump to the default Fault handler
                JMP             Ints.Fault

Ints.IRQ8:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    40      ; Interrupt number
                JMP             Ints.PIC.B
Ints.IRQ9:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    41      ; Interrupt number
                JMP             Ints.PIC.B
Ints.IRQ10:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    42      ; Interrupt number
                JMP             Ints.PIC.B
Ints.IRQ11:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    43      ; Interrupt number
                JMP             Ints.PIC.B
Ints.IRQ12:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    44      ; Interrupt number
                JMP             Ints.PIC.B
Ints.IRQ13:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    45      ; Interrupt number
                JMP             Ints.PIC.B
Ints.IRQ14:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    46      ; Interrupt number
                JMP             Ints.PIC.B
Ints.IRQ15:
                PUSH   DWORD    0       ; Pseudo-fault code
                PUSH   DWORD    47      ; Interrupt number
                JMP             Ints.PIC.B