Compaq ECQD2KCTE manual Required PALcode Instructions

Models: ECQD2KCTE

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PALcode should be written modularly to facilitate the easy replacement or conditional build- ing of each component. Such a practice simplifies the integration of CPU hardware, system platform hardware, console firmware, operating system software, and compilers.

PALcode subsections that are commonly subject to modification include:

Translation Buffer fill

Process structure and context switch

Interrupt and exception frame format and routine dispatch

Privileged PALcode instructions

Transitions to and from console I/O mode

Power-up reset

6.7Required PALcode Instructions

The PALcode instructions listed in Table 6–1and Section C.11 must be recognized by mne- monic and opcode in all operating system implementations, but the effect of each instruction is dependent on the implementation. Compaq defines the operation of these PALcode instruc- tions for operating system implementations supplied by Compaq.

Table 6–1: PALcode Instructions that Require Recognition

Mnemonic

Name

 

 

BPT

Breakpoint trap

BUGCHK

Bugcheck trap

CSERVE

Console service

GENTRAP

Generate trap

RDUNIQUE

Read unique value

SWPPAL

Swap PALcode

WRUNIQUE

Write unique value

 

 

6–4Alpha Architecture Handbook

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Compaq ECQD2KCTE manual Required PALcode Instructions, PALcode Instructions that Require Recognition Mnemonic Name