" HAMMERHEAD" Method and Apparatus for Emergency Flash ROM Recovery Using Shared Socket
Original Publication Date: 1999-Nov-01
Included in the Prior Art Database: 2003-Jun-19
Robert Dixon: AUTHOR [+3]
HAMMERHEAD" Method and Apparatus for Emergency Flash ROM Recovery Using Shared Socket
" HAMMERHEAD" Method and Apparatus for Emergency Flash ROM Recovery
Using Shared Socket
Disclosed is a technique to recover from FLASH MEMORY corruption using
Many computers now have a Service Processor and one or more CPU's. Both
the Service Processor and the main CPU's have separate Electronically Erasable
Programmable Read Only Memories (EEPROM). The Service Processor has a 1M Byte
EEPROM and a socketed 0.5 M Byte EEPROM as a recovery mechanism if the 1M
Byte EEPROM becomes corrupted.
The disclosure described here eliminates the Service Processor 0.5M
Byte recovery EERROM and uses the IPLROS EEPROM socket as the source of the
Service Processor EEPROM in case the Service Processor 1M Byte EEPROM becomes
corrupted. See block diagram below. The 2 X 512kb EEPROM is socketed and
normally contains the Initial Program Load Resident Operating System
(IPLROS). In the case where the Service Processor code becomes corrupted or
needs to be updated, the IPLROS is removed from the 2 X 512kb sockets and a
single 512kb compressed SP recovery image is installed in one socket. The
other socket remains empty.
A jumper changes the logic mode to that of recovery and the SP
executes the SP compressed code from the IPLROS socket. The jumper also
enables the power supply to power the IPLROS sockets. At this point , the SP
running from the compressed recovery image is able to update the 1Mb FLASH
using the normal recovery/decompression algorithm.
S ervice P ro cesso r F lash R eco very...