1. Interrupts and Interrupts Handling

2. Interrupt Routing

3. Initializing the Interrupt Handling Data Structures
The kernel's interrupt handling data structures are set up by the device drivers as they request control of the system's interrupts
The individual device drivers call Linux system services routines to register their interrupt handling routine addresses

4. Interrupt Number Some devices are fixed PCI devices : no problem
e. g. floppy : IRQ 6
PCI devices : no problem
PCI BIOS, PCI initialization
ISA : Linux allows device drivers to probe for their interrupts

5. Interrupt Handling

6. Linux Interrupt Handling
Linux read the interrupt status register of PIC to determine the source
Translate the source into offset int irq_action vector
Linux call into the interrupt handling routines for all of the irqaction data structures