[StillBored]

Ok, I understand how a TPM gets attached to a muxable GPIO block.

But, did no one stop and question whether a TPM should have been on a dedicated block that couldn't be reprogrammed rather than assuming there wouldn't be bugs or whatever in the GPIO pin muxing? Never mind all the additional complexity of assuming page permissions access/etc to shared purpose MMIO regions?

So, IMHO this starts as a hardware bug.

[marshray]

The CPUs and OSs (other than Windows 11) support operation without any TPM.

So either the pin is configurable, or you've wasted a pin that could otherwise be used for decorating the motherboard with RGB LEDs.

Also, the pin layout has to be standardized by the socket specification (eg "LGA 2011"), which may have to retain compatibility for a decade or more. This strongly favors defining reconfigurable over fixed-function pins.