The issue is with the BIOS that Enterprise can't address. Either of the following enhanced features aren't functioning in this BIOS:
- USB hand-off
- USB hand-back
When control of USB is taken (enabled) by something other than the BIOS, the BIOS must release control of the USB to the requester. This requirement applies to DE preboot,
DETech, or Windows.
For example, when DE preboot exits, it notifies the BIOS that it can take back control of USB. But, no requirement exists for the BIOS to actually do so. And, sometimes the BIOS stops responding if it tries to do so. When the BIOS doesn't provide USB legacy support, any 16-bit environment, such as the Windows recovery menu, doesn't have USB support. Without USB support, there's no keyboard support.
NOTE: DETech functions in the same way as DE preboot. So, if you enable USB in
DETech, it also results in taking control from the BIOS. One difference between
DETech and preboot is that, currently, preboot doesn't try to give back control during an Emergency Boot. Even if preboot does return control, the BIOS doesn't take back control after preboot. So, you see the same results as in
DETech.
