问题
I'm studying x86 and Real Time Systems, and I have a question, that is:
Which steps x86 follows to handle any interrupt ?
回答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).
回答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.
来源：https://stackoverflow.com/questions/2897883/what-happens-in-the-x86-architecture-when-an-interrupt-occurs