Power-On Self Test; Post Overview - Sun Microsystems Netra T4 AC100 Service And System Reference Manual

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C H A P T E R

Power-On Self Test

This chapter describes how to initiate power-on self test (POST) diagnostics.
The chapter contains the following topics:
Section 2.1, "POST Overview" on page 2-1
Section 2.2, "Pre-POST Preparation" on page 2-3
Section 2.3, "Running POST" on page 2-4
Section 2.4, "POST Diagnostic Levels" on page 2-4
2.1

POST Overview

POST is a firmware program that is useful in determining if a portion of the system
has failed. POST verifies the core functionality of the system, including the CPU
module(s), motherboard, memory, and some on-board I/O devices, and generates
messages that can be useful in determining the nature of a hardware failure. POST
can be run even if the system is unable to boot.
POST detects most system faults and is located in the motherboard OpenBoot™
PROM. POST can be set to run by the OpenBoot program at power up by setting two
environment variables, the diag-switch? and the diag-level flag, which are
stored on the System Configuration Card.
POST diagnostic and error message reports are displayed on a console.
2-1