This support statement is provided by the Product Management Team.
Tablet support options for DE
This article provides the details needed to be fully supported on Unified Extensible Firmware Interface (UEFI) systems using DE or MNE.
For general details about tablet support for DE and EEPC, see
KB78049 - Tablet support for Drive Encryption 7.1.x.
Overview
UEFI provides protocols between the hardware and applications; DE in general is a consumer of the protocol. Correct functionality DE requires that the following protocols be correctly implemented by the OEM manufacturer:
- Simple Text Input / Simple Text Output (Keyboard *)
- Simple Pointer (Mouse)
- Absolute Pointer (Touch / digitizer)
- Storage Security Command (For OPAL)
* NOTE: We extend the behavior of the keyboard with our own keyboard driver because of the need to translate the keyboards for different languages.
Are all touch-screen devices supported in UEFI?
If you think of UEFI more like an operating system, the OEMs will need to provide software drivers for the hardware contained in that device. For UEFI, the preboot supports both the Simple Pointer Protocol and the Absolute Pointer Protocol. One or both of these are expected to be implemented for all touch-screen devices encountered. If a manufacturer or OEM of the UEFI implementation has failed to implement either of these mechanisms, support for the touch-screen device won't be guaranteed.
NOTES:
- We've found in its own internal testing that not all UEFI implementations from OEMs implement these interfaces. In these instances, the creator of the UEFI implementation on that system leaves out sections of the UEFI specification.
- Some OEMs provide protocol within the BIOS menu, but don't provide it to other applications.
For the latest information about support for Microsoft Surface Tablet, see KB79624 - Supported Microsoft Surface tablet devices with Drive Encryption.
UEFI testing tool
We've created a UEFI testing tool. This tool gives customers, partners, and OEMs the ability to verify in a quick, easy, and straightforward manner whether the DE preboot environment responds to the touch interface. It's a standalone tool and doesn't require DE to be installed.
To obtain the UEFI testing tool and verify if your tablet responds to the touch interface, see KB78050 - How to use the Drive Encryption UEFI testing tool to verify if your tablet responds to the touch interface.
Three available options for tablet support: