<< Click to Display Table of Contents >> Navigation:  ASA-EMulatR Reference Guide > Introduction > Architecture Overview > Chapter 8 - PAL and Privileged Boundary > 8.1 Purpose of This Chapter

This chapter defines the Privileged Architecture Library (PAL) boundary and explains how the EMulatR 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 (CALL_PAL) and exited (HW_REI)

•State transitions at the privileged boundary

•How privilege is enforced at instruction, pipeline, memory, and exception levels

•PAL vector dispatch — EV6 exception vectors and CALL_PAL entry point calculation

•PAL interaction with LL/SC reservations

 

See Also: 4.9 PalBox - Privileged Architecture Library Box; Chapter 7 - Exceptions, Faults, and Interrupts.