IVA-based interruptions are serviced by the operating system. PAL-based interruptions are serviced by PAL firmware, system firmware, and possibly the operating system. PAL-based interruptions are vectored through a set of hardware entry points directly into PAL firmware.
Aborts can be either synchronous or asynchronous with respect to the instruction stream.
The abort may cause the processor to suspend the instruction stream at an unpredictable location with partially updated register or memory state. Aborts are PAL-based interruptions. A processor has detected a hardware error which requires immediate action. Based on the type and severity of the error the processor may be able to recover from the error and continue execution. A processor has been powered-on or a reset request has been sent to it.