I was up to enabling Wake-on-LAN feature on the Dell PowerEdge T20 server with A05 BIOS pre-installed from the delivery.
Once enabled, the server will shut down and immediately turning itself on. Up to 3 times I had to manually press the shutdown button for it to finally power off.
But to the point. What surprised me, was that the recommended way to install the BIOS update was from inside Windows. They provide only .exe files on their web.
Supposing I have a Linux system with rather simple setup, I could install Windows, if there was no other way. But is there?
Indeed, I find it rather non-standard, but you may install this executable file directly from the Boot Manager.
Visit Dell Support.
Enter your Service Tag.
Navigate to Drivers and Download.
Expand the BIOS section.
Click on Download.
Store the file on a FAT32 flash drive.
Click on Show Details.
Check if the SHA-256 matches.
Make sure the server is plugged into a UPS.
Power on the server, pressing F12.
Navigate to BIOS flash update.
Navigate to the proper file system.
Click on the .exe file.
Confirm you want to proceed with the upgrade.
Be patient, it will take like 5 minutes.
This reduced the number of manual pressing of the power button to 1. Not perfect, indeed. But better than before.