Having tried several methods over the years I've ended up using the linux application flashrom. This is fine if you're planning to use your Z series as a Linux box, either with your own flavour of Linux or the Wyse variant. The Binary BIOS image is available from Dell's support pages, but only if you select ThinOS as the operating system.
However, if you are using (or intending to use) Dell's versions of Windows this may not be a good idea. I believe (tho' I haven't verified it) that an element of the Wyse/Dell Windows licence is built into the BIOS. If you update a box using the 'ThinOS' BIOS and then try and use one of the Wyse/Dell Windows builds you may have a problem. At least, with flashrom, you can save a copy of what was here to start off with and go back to the old version if necessary.
See Updating the BIOS for details.
[March 2019] Unfortunately Dell have now withdrawn support for old Wyse products and shut down the old Wyse support server: see here. As a consequence I've removed the old now dead links in the descriptions below but left the articles in place in case you may be able to track down the firmware elsewhere.
Unfortunately updating the firmware and/or the BIOS on a Wyse thin client is often not as slick as it should be. What you'll find here are three approaches to the problem. The first is one that I wrote back in February 2017 that describes how to go about updating the firmware and/or the BIOS using the standard Wyse tools. The second, contributed by Jouni from Finland in January 2019, describes an alternative
Updating just the BIOS on your Wyse Thin client using the official Dell/Wyse tools is a non-trivial and time consuming task as can be seen in this article: Updating a Z90D7. To start with, just for a single update, you are supposed to download a huge software package gigabytes in size. This huge "Software" pack includes a complete embedded Windows operating system along with the small BIOS-update file. Then for installing the software package(s) you'll also need the Dell USB Imaging tool. This is a Windows program that creates a Linux bootable USB-stick which includes all the updates together with the installer program. This stick should run happily on your Wyse box - but it doesn't always.
The USB Imaging tool will install (Dell made) special Linux distro with the updates. As well as the firmware update the updater includes various checks. These checks are to ensure you are installing the correct patches to your system in the right order and also that your particular model has the right licence for the firmware update. Unfortunately the whole process seems to be buggy and can make a simple BIOS update a trial and error process.
After multiple failed BIOS update attempts I noticed that the Dell Linux update environment had been writing to a log file on the usb-stick. In that log file there were two lines that got my attention. Those lines stated something like "signature mismatched" and "LinFlash failed"". So it seems that at the heart of the process there is a simple command-line tool called LinFlash that is doing the actual BIOS update.
This led me on to....
Having discovered the existence of the LinFlash program it became clear that the process could be made a lot simpler. All I had to do was:
The steps below show how I went about this.
One final warning:
So make sure that you do download the files that are intended for your Wyse thin client. LinFlash is pretty general tool and should work with all modern Wyse boxes, but the BIOS firmware file needs to be specific for your Thin client model. *WARNING*
If you want to play it safe then you need to use the Dell/Wyse USB-Imaging tool version that is mentioned in the documentation for your particular model. In my first attempts I was using version 3.1.0 of the tool.
The steps below are what I went through to update the BIOS on my Wyse Z90DW from version 1.0F to version 2.0C. This method should work for other Wyse models which use the USB Imaging tool platform type of installation.
Before starting you need two USB-memory sticks. One to hold the BIOS and LinFlash files and the other stick for a Linux OS that will be the environment from which the BIOS is flashed. In my case I used Puppy Linux for this. Note that in creating the Linux installation on this USB-stick it will probably be formatted and so you should first back up any data on it that you want to keep.
These are few tools you may need along the way.
[David: I would use LiLi and Tiny Core as that's what I use all the time. LiLi also has the advantage of using a FAT32 file system that is readable under Windows so that you can add the BIOS and LinFlash files to the 'Linux' USB stick rather than needing a separate USB stick for them. It's your choice here - stick with what you're comfortable with.]
AXA8_BIOS_B02C0.exe (This is for the X-class Wyse)
AZA0_BIOS_B02C0.exe (This is for Z-class Wyse computers)
WES_Flash.sys_C0.exe
for my computer (Z90DW, which is Z-class) the AZA0_BIOS_B02C0.exe is the right one. Run this executable and it will auto extract itself.
Go to the location where you unpacked it and then follow the path AZA0_BIOS_B02C0\AZA0_BIOS_B02C0\AZA0_BIOS_B02C0\ where you should find the file bios.img. You need to unpack this .img file (1.6MB in size) with 7zip to get the 4MB BIOS image named bios.
Copy this bios file to USB-Fat32 formatted stick.
Phoenix 32-bit Linux Flash Tool, version 1.0.4.0. Copyright (c) 2011-2014 Phoenix Technologies Ltd. Parse command line options.... [ OK ] Initialize.. [ OK ] Read BIOS image [ OK ] Check BIOS image format [ OK ] Please shutdown system to start flashing BIOS! [ OK ]
After the flashing completes the system will reboot again. Press DEL and go to BIOS enter password: Fireport. The BIOS version should be now 2.0C. After BIOS update it's usually good practice to set default values so press F9 to do it.
From Advanced menu I noticed there is a new Digital Audio LED option (Enabled/Disabled). In older BIOS this was all ways on and LED was lit. If you're interested to use digital audio feature on you box, you can find "3.5mm to Toslink adapter" on eBay. Maybe there's some other stuff as well. At least the new BIOS should be more stable with the fixes for your future Linux installations. Enjoy!
If you managed to update your Wyse Thin Client with this guide (or not), please send me a update on Twitter: @fish4rk
This article was contributed by Jouni from Finland.