usb legacy support

Hi,
Why we need to disable usb legacy support???
In some boards without disabling the usb legacy support it works and
in some other boards it doesn't and some times it works in wince 5.0
and not in wince 6.0.

I have seen the o.s is getting hanged at loading the usb drivers when
the usb legacy support is enabled.

I would like to know what exactly make to happen this? If anyone know
it please share!!
Thanks in advance

Werner
Sat Jun 14 07:21:03 PDT 2008

In old days keyb and mouse used PS2 hardware interface. In newer hw usb keyb
and mouse can also emulate old legacy PS2 mode. This means the BIOS will
enable "USB legacy mode" of the chipset. This means that old DOS programs can
work with USB keyb/mouse because the chipset will translate the USB signals
to PS2 signals. Old DOS programs won't see a difference.
Now when using USB on Windows CE, on startup the USB driver (at least the
CE5 USB Intel UHCI driver) is not aware of the fact that the BIOS might have
enabled USB legacy already. I had this problem myself and noticed that
sometimes this caused the usb driver to be confused or even the hw to
malfunction.
The solution is to disable USB legacy mode in the BIOS or to disable USB
legacy mode FIRST in an early state of the USB driver startup code before the
rest of the driver initializes itself. The WinCE6 driver however does this
for Intel UHCI usb hw. It was changed wrt to CE5.
If you have other hw, check the datasheet of the chipset how to do this.

Werner