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Laird WB45NBT
Reference Guide
WB45NBT unit
to be updated
Wi-Fi Access Point
If this is the first time the WB45NBT module is updated, then the AP must be configured for open access. This
ensures that the WB45NBT can obtain a wireless network connection without having to be pre-programmed with a
specific SSID and password. Make sure that there are no other APs around that the WB45NBT may inadvertently
attach to during this update procedure.
Subsequent updates can be scheduled with a prescribed, secured AP but the corresponding profile must first be
created in the unit using the CLI.
Windows or Linux Server
The server must offer DHCP and either HTTP or FTP file services.
The DHCP server must be configured to send an additional parameter called a DHCP Option. The DHCP Option
specifies a Bootfile-Name (DHCP option #67). The Bootfile-Name is a URL of a text file that further describes the
images to be updated (the 'Bootfile'). More information on the bootfile can be found later in this document.
The update program uses the
wget
utility to fetch the remote updates from the file server over the network. It
supports both HTTP and FTP protocols.
Laird WB45NBT
The WB45NBT must be connected to a power source and have a Wi-Fi antenna connected to it.
Bootfile Description
The bootfile (called fw.txt) is a list of all images that are to be updated on the WB45NBT. It resides on the file server
and is pointed to by the Bootfile-Name option in the DHCP Server's configuration.
The format of the bootfile is as follows:
06c73bb2c38f6bd0ecde4b2308595adc
c55870dce9de3347950987b135a9fcd3
5f7f5ebb4717250cdf565e20049debbe
479d3828243c3712efd9a14ecfefb96e
It is not required to list all four images in this file. If only a subset of these images is required to be upgraded, then
only list those particular image files. Each line has three elements:
MD5SUM of image file
Name of the image file
Length of the image file in bytes
Remote Update Methodology
The remote update can be performed automatically using DHCP or manually, using the fw_update program on the
WB45NBT. Both methods are described in the following sections.
Automatic Remote Update
This section describes the default behavior of the WB45NBT firmware supplied by Laird.
After associating with an AP, the WB45NBT sends out a DHCP request. The DHCP server must respond with an IP
address and a Bootfile-Name. The WB45NBT detects if it has received this optional DHCP information. If it does, it
proceeds with the fw_update program using the information in the bootfile to update its flash memory. If the
Embedded Wireless Solutions Support Center:
http://ews-support.lairdtech.com
www.lairdtech.com/wi-fi
at91bs.bin
11444
u-boot.bin
359032
kernel.bin
2091686
rootfs.bin
23592960
16
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Europe: +44-1628-858-940
Hong Kong: +852 2923 0600
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