Bios commands and usb

Hi,
i want to communicate with usb device using bios command.I know that bios
support hid class and mass storage class, but does it support other usb
classes (and is it full support )?is it possible to communicate with usb
device by sending to usb port bytes, treating classes as unneeded element.
how it is during pc initialization (before system starts) is usb device
classified (hid, cdc, msd...) or is it treated as a device with byte
exchange without class abstraction layer?
thanks in advance

mmmm schrieb:
> Hi,
> i want to communicate with usb device using bios command.I know that bios
> support hid class and mass storage class, but does it support other usb
> classes (and is it full support )?

No.

> is it possible to communicate with usb
> device by sending to usb port bytes, treating classes as unneeded element.

No.

> how it is during pc initialization (before system starts) is usb device
> classified (hid, cdc, msd...) or is it treated as a device with byte
> exchange without class abstraction layer?

Keyboard and mouse have a special, simplified "boot" protocol, and maybe 
support for hubs is left out. Otherwise it's just standard USB.


-- 
Mit freundlichen Gr��en

Frank-Christian Kr�gel

>> is it possible to communicate with usb
>> device by sending to usb port bytes, treating classes as unneeded
element.
>
>No.

Is above possible during pc initialization (before system starts)?


Could you give me links with some information about this subject?

mmmm schrieb:
>>> is it possible to communicate with usb
>>> device by sending to usb port bytes, treating classes as unneeded
> element.
>> No.
> 
> Is above possible during pc initialization (before system starts)?

No.

> Could you give me links with some information about this subject?

www.usb.org has got the complete specifications.

-- 
Mit freundlichen Gr��en

Frank-Christian Kr�gel

On May 6, 9:33=A0am, "mmmm" <mro...@gmail.com> wrote:
> >> is it possible to communicate with usb
> >> device by sending to usb port bytes, treating classes as unneeded
> element.
>
> >No.
>
> Is above possible during pc initialization (before system starts)?

Well, sort of.  You would need to write your own driver for the USB
host adapter.   Then you could
take raw USB packets to the device, utilizing whatever capabilities it
has.

But you would need a driver for each potential USB host adapter your
software might encounter.  Usually the operating system takes care of
such hardware localization for you, and presents you instead with a
consistent programming model, the weight of which you seem to be
wanting to avoid.

So my answer would be - "yes" provided that you are willing to invest
a lot of work in developing a solution that only works on a narrow
selection of hardware.  In the embedded world, there are circumstances
where that could be contemplated, but loss in the duplication of
existing effort and the loss of flexibility to easily move to other
hardware which you might otherwise have had.

Going farther in this topic how it is with caps lock on and off before
system starts. When i turn the caps lock or other lock keys, pc sends
message to keyboard and the led turns. what is responsible for sending this
message? how it exectly works?

mmmm wrote:

> Going farther in this topic how it is with caps lock on and off before
> system starts. When i turn the caps lock or other lock keys, pc sends
> message to keyboard and the led turns. what is responsible for sending
> this message? how it exectly works?

If "legacy support" is active in your BIOS setup, the "system management
mode" firmware will do this for you (=emulating a PS/2 keyboard)

jbe