AM4100
NetBootLoader
ID 36126, Rev. 2.0
Page 5 - 3
P R E L I M I N A R Y
5.
NetBootLoader
There are two NBL Flash memories (NBL-Flash0 and NBL-Flash1) available on the AM4100.
These memories are identical and are redundant of one another. Only one of these Flash mem-
ories can be in use at any given time. The other is redundantly available, and, if required, it can
be swapped with the currently used memory.
The AM4100 module is delivered with the NetBootLoader (NBL) software already programmed
into both of the onboard soldered NBL Flash memory chips.
The NetBootLoader itself is a software utility which initializes the module for operation before
turning control over to either an application or to an operator. This software also provides the
capability to monitor and control the operation of the NetBootLoader itself, display system sta-
tus information, to program executable code and data to the NBL Flash memory, and to load
and start application software.
The following sections describe the functioning of the NetBootLoader and how to program the
NBL Flash memory.
5.1
General Operation
Upon power on or a system reset, the NetBootLoader is started. The AM4100 is configured for
operation and control is either passed to an application or an operator. In the event a valid im-
age has been programmed into the NBL Flash memory and no operator or SCRIPT command
intervention takes place, the image is copied into DDR2-SDRAM and control is passed to the
application. If the NetBootLoader does not find a valid image or operator intervention has oc-
curred, control is passed to the operator. The operator now has control to determine the system
status, make configuration changes, read or program the NBL Flash memory, invoke the RUN
command, or to restart or power the system down.
The operator command interfacing with the NetBootLoader is accomplished either via the
SER0 serial port or one of the four Ethernet ports. During the boot operation a command inter-
preter is started which allows the operator to input commands to the NetBootLoader. Prior to
interfacing via an Ethernet port, the port must be configured. This is done either via the SER0
serial port or via a DHCP/BOOTP server.
5.2
NetBootLoader Interfaces
There are three possibilities to interface with the NetBootLoader:
•
Via the SER0 serial interface
•
Via the SER1 serial interface
•
Via an Ethernet port interface
Gaining access to the NetBootLoader is a function of the boot wait time setting, the contents of
the script as defined by the SCRIPT command setting, and the availability of a valid image.
During the boot wait time, which is indicated by the user specific LED (ULED0) blinking green,
the operator may intervene in the boot operation either by entering the ABORT command via
the SER0 serial port, or by performing a successful telnet login via one of the Ethernet ports. If
the operator does not intervene, the boot operation is continued after the boot wait time has
been exceeded.
Summary of Contents for AM4100
Page 19: ...AM4100 Introduction ID 36126 Rev 2 0 Page 1 1 Introduction Chapter 1 1 P R E L I M I N A R Y...
Page 57: ...AM4100 Installation ID 36126 Rev 2 0 Page 3 1 Installation Chapter 1 3 P R E L I M I N A R Y...
Page 65: ...AM4100 Configuration ID 36126 Rev 2 0 Page 4 1 Configuration Chapter 1 4 P R E L I M I N A R Y...
Page 89: ...AM4100 NetBootLoader ID 36126 Rev 2 0 Page 5 1 NetBootLoader Chapter 1 5 P R E L I M I N A R Y...
