What happens in the x86 architecture when an interrupt occurs?

Question

I\'m studying x86 and Real Time Systems, and I have a question, that is:

Which steps x86 follows to handle any interrupt ?

Answer 1

When an interrupt occurs, the CPU does the following:

• Push the current address (contents of the Instruction Pointer) onto the stack; also, push the processor flags (but not all the other processor registers)
• Jump to the address of the ISR (Interrupt Service Routine), which is specified in the Interrupt Descriptor Table.

The ISR should do the following:

• Push any registers which it intends to alter (or, push all registers)
• Handle the interrupt
• Reenable interrupts
• Pop any registers which it pushed
• Use the IRET instructions, which pops the CPU flags and Instruction Pointer value from the stack (and thus returns to whatever was executing when the interrupt occured).

Answer 2

Start here with the Interrupt Descriptor Table. Basically, when an interrupt occurs, flow control jumps to this table and then on to whatever is in this table. Also, I believe all registers are pushed as soon as the interrupt occurs, but I'm not 100% certain of this as it's been a long, long time since I've dealt with this.