Touch Support in EDK2

Thomas Finny

I'm working with software (VeraCrypt) that uses EDK2 to support touch interaction at boot. It doesn't seem to work with the ASUS Vivobook 14 Flip, however, so I rebuilt the app with some debugging code.

There is a TouchDevice detected and a handle is obtained, but when DevicePathFromHandle() is called, it returns 3 (ERROR_UNSUPPORTED). Is DevicePathFromHandle() not returning success directly related to why touch isn't working, or can touch work without this function returning a valid path?

I'm thinking that perhaps EDK2's touch support may be incompatible with the Vivobook 14.

Note that VeraCrypt is built off the UDK2015 branch. Does that branch not have reliable support for touch?