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<< Click to Display Table of Contents >> Navigation: ASA-EMulatR Reference Guide > Introduction > Architecture Overview > Chapter 8 - PAL and Privileged Boundary |
This chapter defines the Privileged Architecture Library (PAL) boundary and explains how the AlphaCPU emulator enforces architectural privilege separation.
PAL is not an operating system and not firmware in the traditional sense. It is a hardware-defined privileged execution environment that exists below the operating system and above the microarchitecture.
This chapter explains:
•What PAL is and is not
•How PAL mode is entered and exited
•What state transitions occur at the boundary
•How privilege is enforced
•Why PAL entry must serialize the pipeline
•How PAL integrates with exceptions, interrupts, and SMP