upslug2 - utility to upgrade the firmware of a NSLU2 via the network
upslug2 is a command line program intended to allow the upgrade the
firmware of a Linksys NSLU2 (Network Storage Link for USB 2.0 Disk
Drives) to new or different versions. When a NSLU2 in the local
network is put in upgrade mode, upslug2 can connect to it and upload a
upslug2 will accept a full firmware image but it can also upgrade the
flash from individual files holding the kernel, ramdisk and root
filesystem. upslug2 provides status information during the upgrade
process and verifies the written image after the upgrade.
Reprogram the complete flash, including the RedBoot boot loader
and the SysConf partition holding configuration information.
Using this option may result in the NSLU2 becoming permanently
unusable! By default, upslug2 will not touch these two
partitions since this allows flashing a new firmware if an
uploaded firmware does not work. This is not possible if
RedBoot itself is damaged. Use with caution.
The network device on the host machine connected to the network
on which the NSLU2 is located. (Default: eth0).
The endianness of the files to be uploaded. upslug2 will
usually detected the endianness automatically but this option
can be used to force byte swapping to occur. This option
accepts three values, separated by comma: endianness of kernel,
data and RedBoot FIS directory. Valid values are l (little
endian), p (pdp endian) and b (big endian). (Default: ,b,b)
The MAC address of the host system.
Show summary of options.
The complete flash image to use.
A root filesystem, usually of type jffs.
A compressed kernel zImage image.
Do not reboot after upgrade
FIS directory payload. There are about 140 Kb in the last block
(between the FIS dir and the trailer at the end) which can be
used for data.
A compressed ramdisk image.
A ram paylod (replaced ramdisk). (FIXME: if it replaced the
ramdisk, why cannot you just use the -r option? What’s the
The MAC address of the NSLU2 to upgrade. Without this option,
upslug2 will only perform an upgrade if there is just one NSLU2
in upgrade mode.
Do not verify the image, only upgrade.
Do not write to flash, only verify the image.
Options to specify firmware information
The following options should be used when individual kernel, ramdisk
and root filesystem files are specified rather than a complete firmware
Extra version information, a 2 byte value. (Default: 0x90f7)
The firmware version, a 2 byte value. (Default: 0x2329)
The product ID, a 2 byte value. (Default: 1)
The protocol ID, a 2 byte value. (Default: 0)
In order to use upslug2 the NSLU2 which is to be upgraded has to be put
in upgrade mode:
1. Disconnect any disks and/or devices from the USB ports.
2. Power off the NSLU2
3. Press and hold the reset button (accessible through the small hole
on the back just above the power input).
4. Press and release the power button to power on the NSLU2.
5. Wait for 10 seconds watching the ready/status LED. After 10 seconds
it will change from amber to red. Immediately release the reset button.
6. The NSLU2 ready/status LED will flash alternately red/green (there
is a 1 second delay before the first green). The NSLU2 is now in
If you decide not to flash the image the NSLU2 can be rebooted by
disconnecting the power. If the ready/status LED does not turn green
after step four it will remain red for several seconds then flash
amber. This happens if you do not release the reset button in time -
pull the power, reconnect it and repeat from the second step.
Once the NSLU2 is in upgrade mode it will remain in this state until
either the power is connected or a new image has been flashed. If the
flash fails the NSLU2 will (eventually) return to upgrade mode
The most common use of upslug2 is the following:
upslug2 --image NSLU2_V23R63.bin
This specifies a complete firmware image which will be written to
Alternatively, kernel, ramdisk and root filesystem can be specified
upslug2 -k nslu2-zImage -r ramdisk -j root.jffs
In this case, the options -E, -F, -P and -T should typically be
specified as well.
By default, upslug2 will search for the NSLU2 on the network on your
eth0 network interface. If the network is on a different interface,
you can easily specify it:
upslug2 -d eth1 --image NSLU2_V23R63.bin
If there are potentially more than one NSLU2 in your network which may
be in upgrade mode, you can specify its MAC address:
upslug2 -t 00:11:85:12:34:56 --image NSLU2_V23R63.bin
John Bowler <email@example.com>