- Download the "Dell TPM 2.0 Firmware Update Utility" from the Dell support website
- Create a FreeDOS USB stick:
- Format USB stick to FAT32
- Mount USB stick (required by unetbootin)
- Download unetbootin
- Run unetbootin (as root), select FreeDOS, select the right volume, and install
- Copy the downloaded firmware update file to the USB stick
- Boot the laptop from the USB stick
- Once on the FreeDOS prompt, move to the USB stick volume by issuing
C:
- Execute the firmware update file, validate when prompted, device will reboot once done
- After rebooting, the Dell logo should appear with a message saying that the TPM is being upgraded
\o/ TADAAAAAAA \o/
TPM 2.0 now works!
Many thanks @mdeous
Just a note, you need to use the initial version of Dell's 1.2 to 2.0 TPM update tool. Later releases don't seem to work with FreeDOS.
DellTpm2.0_Fw1.3.1.0_V1_64.exe worked for me, the most current was 'V3' and wouldn't open.