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WB45NBT
Reference Guide
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MD5SUM of image file
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Name of the image file
Length of the image file in bytes
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8.1.3.1 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.
8.1.3.2 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
MD5SUM of the components listed in the bootfile match what is already on the device, then nothing is updated
and the WB45NBT continues to run normally.
After all the updates are complete, the bootloader is made aware of the new kernel and/or filesystem and loads
these new images on the next reboot. The WB45NBT reboots into the newly updated system automatically after
the update process is complete.
8.1.3.3 Manual Remote Update
The fw_update program can be invoked from the CLI. Access to the CLI can be obtained either through the serial
port or over a network connection through the use of SSH. By default, an SSH server is enabled on the
WB45NBT. The username is root and the password is summit. It is important that the password is changed to
something different in the filesystem of the end product.
When manually starting the fw_update program, the URL for the fw.txt file must be supplied as an argument to
the fw_update program. For example:
fw_update
http://192.168.1.10/wb45n/fw.txt
Note: WB45NBT requires a valid IP address before it can fetch the image files from the network. If the
WB45NBT is configured as a bridge (which may not have an IP address), then it must be configured
with a valid IP address on its network interface before running the fw_update program. This can be
done by stopping the bridging (/etc/network/bridge.sh stop) and then using udhcpc -i wlan0 or the ifrc
utility to configure the IP address settings of the wireless interface.
After the update program has completed its process, the bootloader becomes aware of the new kernel and/or
filesystem. The new images are loaded on the next reboot. Issue the reboot command to reboot the WB45NBT.
When invoked manually, the fw_update program does not automatically reboot the WB45NBT after it has
completed updating the device.
8.1.3.4 Limitations
These methods of updating are destructive to existing data on the device because existing data in the flash
memory of the WB45NBT is overwritten by the new image.
Embedded Wireless Solutions Support Center:
http://ews-support.lairdtech.com
www.lairdtech.com/wi-fi
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Europe: +44-1628-858-940
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