.global int0 .global int1 .global int2 .global int3 .global int4 .global int5 .global int6 .global int7 .global int8 .global int9 .global int10 .global int11 .global int12 .global int13 .global int14 .global int15 .global int128 .global int129 .global int255 .global exc0 .global exc1 .global exc2 .global exc3 .global exc4 .global exc5 .global exc6 .global exc7 .global exc8 .global exc9 .global exc10 .global exc11 .global exc12 .global exc13 .global exc14 .global exc15 .global exc16 .global exc17 .global exc18 // nothing to ack .macro ack0 .endm // ack master .macro ack1 push %eax // persist mov $0x20,%al out %al,$0x20 pop %eax // load original .endm // ack master and servant .macro ack2 push %eax // persist mov $0x20,%al out %al,$0xa0 // slave out %al,$0x20 // master pop %eax // load original .endm .macro intx ack num func /* Once we arrived here the stack already contains 3x 32bit values, which will be poped by 'iret' - eflags - return code segment selector - return instruction pointer There are two possiblities concerning our stack position: a) if the interrupt occured while kernel code was executed we are on the same stack and have no clue about the stack alignment b) if the interrupt occured while user code was executed the configured tss.esp0 was used, in this case we are at the start of the esp0 stack. */ \ack //acknowledge interrupt //also remember that we will get new interrupts only //after iret or reenabling themn explicitly! push $0x666 //make room for potential C functions 'return value'. //we use eax already for esp (so we can context switch) push $0x0 //indicate if we want to return the value in ebx 0x0=NO pusha //Push all standard registers 8 regs x 4bytes/32bit push %ds //Push data segment push %es //etc... push %fs push %gs mov %esp,%eax // remember THIS stack position and $-16,%esp // padding to align stack on 16byte boundary before CALL sub $8,%esp // ... push \num // pass in this interrupt number push %eax // pass in original %esp (saved just few lines before) call \func mov %eax,%esp // use the %esp we got from c function pop %gs // pop everything back... pop %fs // ... pop %es pop %ds popa cmp $0x0,(%esp) je skip\num pop %ebx pop %ebx jmp ret\num skip\num: add $8,%esp // potentially set return value to eax to return to the caller ret\num: iret // pops the return instruction pointer, return code segment selector, and EFLAGS image from the stack .endm .macro excx func call \func jmp . .endm int0: intx ack1 $0 interrupt_handler int1: intx ack1 $1 interrupt_handler int2: intx ack1 $2 interrupt_handler int3: intx ack1 $3 interrupt_handler int4: intx ack1 $4 interrupt_handler int5: intx ack1 $5 interrupt_handler int6: intx ack1 $6 interrupt_handler int7: intx ack1 $7 interrupt_handler int8: intx ack2 $8 interrupt_handler int9: intx ack2 $9 interrupt_handler int10: intx ack2 $10 interrupt_handler int11: intx ack2 $11 interrupt_handler int12: intx ack2 $12 interrupt_handler int13: intx ack2 $13 interrupt_handler int14: intx ack2 $14 interrupt_handler int15: intx ack2 $15 interrupt_handler int128: intx ack0 $128 interrupt_handler int129: intx ack0 $129 interrupt_handler int255: intx ack0 $255 interrupt_handler exc0: excx exception_handle_0 exc1: excx exception_handle_1 exc2: excx exception_handle_2 exc3: excx exception_handle_3 exc4: excx exception_handle_4 exc5: excx exception_handle_5 exc6: excx exception_handle_6 exc7: excx exception_handle_7 exc8: excx exception_handle_8 exc9: excx exception_handle_9 exc10: excx exception_handle_10 exc11: excx exception_handle_11 exc12: excx exception_handle_12 exc13: excx exception_handle_13 exc14: excx exception_handle_14 exc15: excx exception_handle_15 exc16: excx exception_handle_16 exc17: excx exception_handle_17 exc18: excx exception_handle_18