Software Delegated Exception Interface (SDEI) provides a mechanism for registering and servicing system events from system firmware. This specification defines a standard interface that is vendor-neutral, interoperable, and software portable. The interface is offered by a higher Exception level to a lower Exception level, in other words, by a Secure platform firmware to hypervisor or hypervisor to OS or both.
System events are high priority events, which must be serviced immediately by an OS or hypervisor. These events are often orthogonal to normal OS operation and the events can be handled, even when the OS is executing within its own critical section with interrupts masked. System events can be provided to support:
- Platform error handling (RAS)
- Software watchdog timer
- Sample-based profiling
- Kernel debugger