HSOF/ACS PATCH PROCESS DESCRIPTION


Patches for HSOF/ACS are distributed in the form of text files that may 
be installed through scripting, or manually installed by directly 
entering code into the controller. 


The HSOF/ACS utility CLCP (Code Load Code Patch) is utilized to input 
the text patches into the controllers NVRAM space. The utility may be 
run from the CLI of the HSx subsystem, or invoked via supported host 
connections.  The utility checks the length and validity of each patch 
after entry through the use of a checksum code on the final line. 
If there is an error during data entry, the patch is not stored in 
NVRAM, and CLCP will return to the main menu. This can be quite time 
consuming if a patch is rejected after a long manual entry process.


The patches are applied against the base-level operating firmware 
stored on PCMCIA cards residing in each controller. These cards are 
supplied when the controller is purchased, and can be upgraded through 
a software update service, or replaced when defective through a 
maintenance contract. All controllers and any subsequent controller 
replacements must go through this patch installation process to 
maintain the latest firmware release level. The preferred method of 
patch installation is through code scripting to automate and speed up 
the process.
 

During the controller boot sequence the HSOF/ACS software is loaded 
into program memory from the PCMCIA card. Any patches that reside in 
NVRAM are then applied to the HSOF/ACS base code by an internal 
patching facility. As part of this patch facility, the patch integrity 
is verified against the checksum code before proceeding with any 
program image modification in memory. 


The patch routine compares the current revision of program image, and 
only installs entries in patch space that are sequential in version. 
For this reason patches cannot be skipped, or expected portions of the 
operating system will be missing. If only patch versions -1, -2, -3, 
were stored in NVRAM, a 5 patch would not load since the program could 
not locate the 4 patch. To protect the operating system integrity, the 
controller memory modification routine would then terminate after 
installing the 3 patch. The program also disregards patches it locates 
that do not match the current firmware base-level revision. So to 
prevent unnecessary memory consumption, all patches belonging to 
previous base-level firmware revisions should be deleted from NVRAM.


*************** HEWLETT-PACKARD COMPANY  DISCLAIMER *****************
* In accordance with Hewlett-Packard's commitment to maintain the    *
* highest level of customer satisfaction, patches for HSG60/HSG80    *
* are now available on the hp.com web site. The availability of      *
* patches is in no way an obligation by Hewlett-Packard to continue  *
* this practice in the future.                                       *
**********************************************************************