This site is for those of us who are repurposing thin clients and, as such, have little interest in firmware updates from the manufacturer's site. However the exception to this rule are updates to the BIOS. With some manufacturers (such as HP) the BIOS update is a stand-alone process and relatively simple to carry out. Unfortunately it isn't with Dell/Wyse.
As with all system providers Dell/Wyse have a management infrastructure for their thin clients that includes a mechanism for the deployment of upgrades and/or re-installation of system firmware. The firmware updates (and the installation tools) are packaged in a format particular to the management firmware and, in some instances, to the existing firmware that is running on the thin clients.
Those of us who are who are just repurposing a thin client have no interest in implementing such an infrastructure, and anyway there may also the requirement that the thin client itself is already running a standard build of Dell/Wyse firmware.
As of March 2019 Dell shutdown the old Wyse support site and moved support to a new site. Unfortunately they instituted a policy of limiting the support files to those products that are current. All the files for products that have passed the EOSL landmark have vanished. This can include early releases of the firmware for the current product line. For example, at the time of writing (July 2019), checking the offerings for my Z90D7 I find two possibilities:
Both are for a Z90D7 fitted with 16GB of flash (mine came with 4GB) and one is 10GB download whilst the other is an 8GB download. Somewhere in the download package will be the latest BIOS, but a 10GB download to get hold of a 2MB BIOS file? You must be joking!
However, when looking at support for the ThinOS variant, life is much better as there is an option to download a binary image of the BIOS - a 2MB download, but then again there is no stand-alone tool to write it into the BIOS chip - that seems to be built into the ThinOS client firmware.
Having found and downloaded the update file for a Windows based thin client there is then the problem of extracting the BIOS file and getting it installed in the thin client. Here we have a number of options:
In practice I have had limited success with this approach. The last time I used it to update the BIOS on a Z90D7 I did have to follow a specific upgrade path in order to get to the point where I could install the latest firmware. The necessary interim downloads are no longer on the support site.
One correspondent took this approach but others have had difficulty duplicating his approach.
An obvious approach is to extract the relevant programs from the Dell Wyse software. These tools have the advantage that they are already configured to access/read/write the onboard BIOS chip. However their actual use is undocumented and, in the case of the USB Firmware Tool, the BIOS image files appear to be signed in some way which makes further work if you've obtained the BIOS image from another source.
A software alternative is the Linux program flashrom which, as the name implies, has been written to read/write the plethora of BIOS chips fitted to PCs. Originally, when experimenting with a Z90D7 and a D10D I found that, whilst it recognises the CPU and support chips fitted and it does support the BIOS chip (a MX25L1606E), it just hung whilst trying to find it. This was using a flashrom binary that I had built under Tiny Core 10.1. I subsequently went back and tried again with a version that I had built under Tiny Core 8.2.1. This worked perfectly. Why the 10.1 build doesn't work I don't know - and kind-of don't care as I do have a working version with 8.2.1.
When I was having difficulty with flashrom and its internal programmer that just left some form of hardware programmer. A quick search of the Internet revealed that there was a cheap USB programmer available that supported the MX25L1606E BIOS chip - the CH341A. By cheap I mean only a few $$ if buying from the far east, maybe £5-£10 if buying locally.