Errors Captured By Srm Console; Palcode Overview; Double Error Halt While In Pal - Compaq ES40CSLP Installation, User & Service Manual

Troubleshooting and Diagnostics

6.7.5 Errors Captured by SRM Console

When the system is running PALcode, neither double error halts nor machine checks result in
error log entries. These errors cause the machine to return to the SRM console, not to the
operating system. The SRM console displays an error message. Use the SRM info command to
help determine the error.

6.7.5.1 PALcode Overview

PALcode, privileged architecture library code, is used to implement a number of functions at
the machine level without the use of microcode. This allows operating systems to make
common calls to PALcode routines without knowing the hardware specifics of each system the
operating system is running on. PALcode routines handle:
•
Instructions that require complex sequencing, such as atomic operations
•
Instructions that require VAX-style interlocked memory access
•
Privileged instructions
•
Memory management
•
Context swapping
•
Interrupt and exception dispatching
•
Power-up initialization and booting
•
Console functions
•
Emulation of instructions with no hardware support

6.7.5.2 Double Error Halt While in PAL

A double error halt occurs under the following conditions:
•
A machine check occurs.
•
PAL completes its tasks and returns control of the system to the operating system.
•
A second machine check occurs before the operating system completes its tasks.
The machine returns to the console and displays the following message:
halt code = 6
double error halt
PC
Your system has halted due to an irrecoverable error. Record the
error halt code and PC and contact your Compaq Services
representative. In addition, type INFO 5 and INFO 8 at the console
and record the results.
The info 5 command causes the SRM console to read the PAL-built logout area that contains
all the data used by the operating system to create the error entry.
The info 8 command causes the SRM console to read the IOD 0 and IOD 1 registers.
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