Several months back, I was helping a customer debug an issue where I needed to install the GA release of ESXi 6.7! Yikes, it certainly has been a minute since I have installed anything older than 7.x but I figured it should still work fine with recent hardware like an Intel NUC systems, right?
After the ESXi installer started to boot up, it eventually halted with the following message:
Shutting down firmware services...
Using 'simple offset' UEFI RTS mapping policy
I decided to give it one more go by using a more recent release of ESXi 6.7 Update 3 and to my surprise, not only did ESXi installed perfectly fine but I did not run into the error message shown abvove!
I then realized that perhaps this has something to do with the ESXi bootloader, like any piece of software, there are fixes and enhancements with newer releases. I also recall a conversation with one of our Engineers that the ESXi bootloader is also designed to be backwards compatible, so that gave me an idea to try replacing the default ESXi 6.7 GA bootloader files with the ones found in ESXi 6.7 Update 3 and now I was able to install ESXi 6.7 GA release!
However, my success did not last very long as I ran into a slightly different message after the initial reboot:
Shutting down firmware services…
UEFI runtime services support is disabled