Hardware Reference
In-Depth Information
Table 5.17 Advanced USB Configuration Menu
Legacy USB support means support for USB keyboards and mice independent of the OS
or drivers. If you are using USB keyboards and mice with this option disabled, you will
findthat the keyboard andmouse are notfunctional until aUSB-aware OSis loaded. This
canbeaproblemwhenrunningdiagnosticssoftware,olderOSs,orotherapplications that
run outside of USB-aware OSs or environments.
Note that even with legacy support disabled, the system still recognizes a USB keyboard
and enables it to work during the POST and BIOS Setup. If USB legacy support is dis-
abled (the default on some systems), the system operates as follows:
1.
When you power up the computer, USB legacy support is disabled.
2.
POST begins.
3.
The BIOS temporarily enables USB legacy support. This allows you to use a USB
keyboard to enter the setup program or Maintenance mode.
4.
POSTcompletesanddisablesUSBlegacysupport(unlessitwassettoEnabledwhile
in Setup).
5.
The OS loads. While the OS is loading, USB keyboards and mice are not recognized.
After the OS loads the USB drivers, the USB devices are recognized.
To install an OS that supports USB when using a USB keyboard or mouse, enable USB
legacy support in BIOS Setup and follow the OS's installation instructions. After the OS
isinstalled andtheUSBdriversareconfigured,USBlegacysupportisnolongerusedand
