Broadcom BCM5722 - Overview; Section 4: NVRAM Configuration; Self-Boot

BCM5722 Programmer’s Guide
10/15/07
Broadcom Corporation
Page 41 NVRAM Configuration Document 5722-PG101-R
Section 4: NVRAM Configuration
OVERVIEW
Broadcom NetXtreme and NetLink controllers require the use of an external non-volatile memory (NVRAM) device (Flash or
SEEPROM), which contains a bootcode program that the controller's on-chip CPU core loads and executes upon release
from reset. This external NVRAM device also contains many configuration items that direct the behavior of the controller,
enable/disable various management and/or value-add firmware components, etc.
All configuration settings are default-configured in the official release binary image files provided in Broadcom's CD software
releases. However, the settings chosen as default by Broadcom may not be what best suits a particular OEM's application,
so some settings may need to be changed by the OEM.
Details relating to the NVRAM can be found in
NetXtreme/NetLink NVRAM Access Broadcom application note (Netxtreme-
AN50X-R). Some of the topics addressed by this application note include the following:
• Programming NVRAM (sample C code, x86 assembly)
• NVRAM map
• Configuration settings
• Bootcode
• Multiple boot agent (MBA), PXE, etc.
• Management firmware (ASF)
SELF-BOOT
Some NetLink controllers offer a capability known as self-boot. Self-boot allows the controller to use a very small, low-cost,
external NVRAM device that contains only a very condensed amount of configuration information, along with any small
bootcode patches that may be necessary to optimize the functionality of a particular controller.
Details relating to self-boot can be found in
Self Boot Option (5754X_5787X-AN10X-R) and NetXtreme/NetLink Software
Self-Boot NVRAM
(NetXtreme-AN40X-R) Broadcom application notes.
Note: NVRAM CRC-32: There are multiple distinct regions contained within the NVRAM map. Each of these
regions has its own CRC-32 checksum value associated with it. If any data element contained within a region is
modified, then that region's CRC-32 value must also be updated. Details relating to calculating the CRC-32 can
be found in
Calculating CRC32 Checksums for Broadcom NetLink, NetXtreme, and NetXtreme II Controllers
Broadcom application note (NetXtreme_NetXtremeII-AN20X-R).