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MB991AF
User’s Manual
4.4.12 USB Configuration
BIOS Setting
Description
Legacy USB Support
Enables Legacy USB support.
•
Auto
disables legacy support if there is no
USB device connected.
•
Disable
keeps USB devices available only for
EFI applications.
XHCI Hand-off
This is a workaround for OSes without XHCI
hand-off support. The XHCI ownership change
should be claimed by XHCI driver.
USB Mass Storage
Driver Support
Enables / Disables the support for USB mass
storage driver.
Port 60/64 Emulation
Enables / Disables I/O port 60h/64h emulation
support. This should be enabled for the complete
USB keyboard legacy support for non-USB
aware OSes.
USB Transfer
time-out
The time-out value for control, bulk, and Interrupt
transfers.
Options: 1 sec / 5 sec / 10 sec / 20 sec
Device reset time-out
Seconds of delaying execution of start unit
command to USB mass storage device.
Options: 10 sec / 20 sec / 30 sec / 40 sec