The kernel is the central component of an Operating System (OS). Outline how the kernel of an OS acts as an interrupt handler.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2024). The mark or mark type is shown in brackets.

1. [2] One mark per mark point (Max 2)
2. [2] MP1 the kernel receives a signal when an interrupt is generated
3. [2] MP2 the kernel checks the priority and reviews the status/priority of the current interrupts
4. [2] MP3 system enters kernel mode if the type of interrupt is of higher priority than the current process
5. [2] MP4 the kernel consults the interrupt dispatch table / IDT
6. [2] MP5 and saves the state of the interrupted process / contents of the registers on the kernel stack
7. [2] MP6 the kernel restores the process state e.g. contents of registers once the interrupt is serviced
8. [1] One mark per mark point (Max 1)
9. [1] MP1 multi-tasking allows computers to carry out / seem to carry out more than one process at a time
10. [2] One mark per mark point (Max 2)
11. [2] MP1 processor time/common hardware and resources is/are shared between tasks
12. [2] MP2 scheduling is used to decide on the processes to be carried out to ensure multi-tasking operates correctly / efficiently / without clashes
13. [2] MP3 one task of a higher priority can interrupt another task that is currently running