Re: OS independent , Platform independent USB device driver

Janaka <janakas@xxxxxxxxxxxx> wrote:

As Tim points out libusb installs its own generic device driver in
windows (that sometimes stuffs up windows native USB functionality).
But this part of libusb is never portable; its windows specific. I
wouldn't call the portable bits of libusb a "user space device
driver". Its just a easy access wrapper.

I have to disgree with you, because this kind of assertion raises the hopes
of USB beginners who think they can whack their USB devices just like
reading from a disk file. We see this all the time on the libusb mailing
list.

Libusb provides an interface that is much like WinUSB on Windows. Neither
of them are extra-friendly easy access wrappers. Both are just mappings of
the kernel-level interfaces to user-mode. In order to use either libusb or
WinUSB successfully, you really do have to write a user-mode device driver.
You have to understand descriptors, classes, interfaces, endpoints, pipes,
packets, frames, URBs, and control messages. It requires a level of
expertise that I associate with "device drivers", not "easy access
wrappers".
--
Tim Roberts, timr@xxxxxxxxx
Providenza & Boekelheide, Inc.
.

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