Kernel mode
Privileged mode used by the OS
Access privileged processor features
- restricted processor features and registers
- Enable and disable Interrupts, set up interrupt handlers
- Controls the System Call Interface
- Can modify TLB
- can interact directly with the peripherals
- Processes cannot read or write kernel memory
- Processes cannot directly call kernel functions
Kernel mode can only be accessed through well defined entry points
Interrupts, exceptions and System Calls use the same mechanism
See also Trapframe