I'm investigating options available for creating a virtual USB device (say, a keyboard or a mass storage device), so to emulate its function as needed and to allow a userspace app to emulate its insertion/removal at will.
What I am not clear about is how to go about the emulation of insertion/removal. It seems that one option is to emulate a (virtual) USB hub and have it fake the device arrival/departure events (and I would also supply the device driver for my virtual USB device and that's where my device logic will reside).
I know my way around Windows kernel (having written NDIS miniport drivers), not afraid of SoftICE, but USB is not my domain, just starting out with it.
Am I on the right track with the virtual hub approach? If so, is developing virtual hub drivers supported by WDK (it doesn't seem to be)?
Any other options?
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(Edit) Forgot to mention - I am aware of DSF, but it is not supported on W8.
Am I on the right track with the virtual hub approach?
In short - yes, I was right.
That's how USBIP does it and it's a relatively simple way to go. Also, see this comment by Eugen.
I don't know if you are aware, but Microsoft released to Win10 the UDE (USB device emulation).
In the section Write a UDE client driver they describe exactly what you want.
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I am prototyping a keyboard using a Pi Zero, and I plan to set the Pi Zero up so that it emulates an HID-compliant USB keyboard (for Windows). There are many guides on how to do this, so I do not think this will be an issue. The additional functionality of this keyboard is going to require the ability to configure certain aspects keyboard on the host machine and send those configurations back up to the device.
My understanding is that once I have the pi zero emulating an HID keyboard, I will not have to do any extra work with Windows to get the host to accept the new keyboard device - it will automatically recognize the HID device and use the correct built-in driver. The configuration bit, however, I will have to work on myself. I was planning on writing a Win32 application that calls WinUSB as the other driver that handles transfer for the configurations.
On the MSDN page for selecting a USB driver model, it states that WinUSB is a good option if:
Your device is accessed by a single application.
The question stands thusly:
Does having my device configured as an HID keyboard prohibit me from being able to use WinUSB as a configuration driver? More specifically, does having my keyboard constantly open in an HID filter driver (I believe the HID host is a filter driver) count as the device being used in one application already, where the configuration application would be a second?
I believe this answers my question.
https://social.msdn.microsoft.com/Forums/en-US/9687e8ba-9eb0-4d41-a8ac-973a029e05b2/winusb-sample-to-read-inputs-from-keyboard
only one driver can be installed on the device, either HID or winusb. you could force winusb onto the keyboard but then it would stop looking like a keyboard to the OS.
Ignoring the irking lack of capitalization in this post, this seems to state pretty conclusively that a separate driver needs to be written. How unfortunate.
I already read Creating a Virtual USB Device and Virtual USB device about creating a virtual USB Device. I am familiar with the Plug and Play handling by Windows as well as the driver mechanism.
So far I understood that first of all I would have to create another device driver which is used for the virtual USB device. But I am still lost on the point what actually is the virtual device. How would I control the behaviour of my virtual device?
Background: I develop a software which acts as a communication layer between an API and the USB driver. The behaviour of the USB device is well known to me. I even could provide the whole firmware. For reasons of QA, I would like to test my software without the bugs of the whole system or on the other hand easily implement errors to see how the software reacts. But what kind of software could implement this behaviour as virtual device?
Any documentations / instructions are welcome!
I used the USB/IP project to emulate USB devices in Python. Maybe it can help you to create your virtual USB devices:
http://breaking-the-system.blogspot.com/2014/08/emulating-usb-devices-in-python-with-no.html
I'd like to modify a USB driver to send and receive USB data over a network.
Take for example, an iMac and a PC. I have an iPod plugged in to my PC (in NY). I want my iMac (in LA) to recognize the iPod as plugged in to a local USB port and be able to communicate with the iPod.
Forget my qualifications, or lack thereof (I have background in web, iOS apps, I've toyed with Java and C).
Where can I get source code for a USB driver for Windows that I can modify? Mac OS?
Any tips or pointers towards accomplishing my goal would be appreciated as well.
It looks like folks are coming up with something close to what you want. If you do decide to roll your own, the USB driver source you asked for is libusb.
On the Mac OS X end, drivers are built up in a stack. What you want to do should be relatively simple (nothing is really simple in kernel land). You need to create a driver that can communicate over ethernet with the PC and looks like a USB device to the driver matching software. Then everything else will happen automatically.
The source code is available for Apple's USB stack. You should also read about the IOKit API and IOKit device driver guidelines and IOKit fundamentals.
Oh yes and you say you have toyed with Java and C. To write device drivers on OS X, you'll need to learn some C++.
I suggest you to go see USBIP project. This is available on Linux and Windows, but not clear for MAC. If you can get a VHCI-Controller driver installed for MAC, we can kick start USBIP for MAC.
Sounds quite like this product, a bit unsure if theirs works over wide-area networks though.
I have a general idea of how I'd go about it, but not any specifics. Basically, I'd use the platform's driver development kit to write a USB device emulator on the client machine. I'd then add a virtual device to that system called "Networked USB Host", or something similar that maintains an open port to listen for communication from the server and passes it on to your virtual USB device. IIRC, the Windows DDK comes with a USB simulation framework that might be able to help you with this.
On the server, you'd have to hook into the USB subsystem to send raw USB packets to the client machine. libpcap and wireshark have USB capturing facilities for that, but I'm not sure if this works with winpcap and the Windows version of wireshark as well.
EDIT: Look at this for cross-platform USB capture alternatives.
You can buy OSR USB learning kit: https://www.osronline.com/custom.cfm?name=index_fullframeset.cfm&pageURL=https://www.osronline.com/store/index.cfm
This is actually small USB device with known interface. Windows Driver Kit (WDK) contains sample KMDF driver for this device: http://www.microsoft.com/whdc/driver/wdk/
This is good starting point to learn Windows Drivers development, and USB drivers development specifically. However, it is still far away from your problem solution.
Can't you use some sort of Remote Desktop?
Do you know a way to use the Windows XP API to reset the USB bus? In other words, I'd like the OS to kick out any USB devices that are currently connected, and then auto-detect everything anew.
I'm aware of devcon, and I suppose I could do system calls out to it, but I'm hoping for a direct call into the API.
From kernel mode: You can force a specific USB device to be re-connected, as if it was unplugged and replugged again, by sending an IOCTL_INTERNAL_USB_CYCLE_PORT to its PDO. (This can only be done from a kernel mode, e.g. through a helper driver.) This 'cycle' operation will cause a USB reset to occur, after which the device would be re-enumerated. For example, if the device comes back with a different USB device descriptor, a different driver may be matched for it.
From user mode: You can do this by ejecting the device through the CfgMgr API. For example, to go over all USB hubs and eject all devices:
Find all devices having device interface GUID_DEVINTERFACE_USB_HUB with SetupDiGetClassDevs(... DIGCF_DEVICEINTERFACE).
Enumerate over the returned device information set (SetupDiEnumDeviceInfo).
For each device, get the DevInst member:
Invoke CM_Get_Child(DevInst) and then CM_Get_Sibling repeatedly to go over all child nodes of the hub (i.e. the USB devices).
For each child node, call CM_Request_Device_Eject.
Well, use can use the Setup API (SetupDiXXX functions) to enumerate the USB devices in the system, and then call WinUsb_ResetPipe on each one, but I'm not sure if that's what you're looking for. It's been a while since I worked with USB devices, but as I recall, there is no standard way to reset a device (i.e. simulate a power off/power on cycle). If it's possible for a particular device, you'd have to send an appropriate IOCTL (using DeviceIOControl) to the driver. The IOCTL would vary from manufacturer to manufacturer.
It's possible to cycle the parent port on the USB hub the device is attached to, as well. This will result in, among other things, apparrent unplug/replug actions, as you will see a balloon popup when this occurs.
Much of this is poorly documented, and honestly, I've gotten the impression there are only a handful of people at Microsoft who really understand it well. The design decision I've made for future devices I design is that I intend to include watchdog functionality on both sides, as well as a device-side full reset function. That way, if the device figures out it is confused, it can just cut its own power for a second and fully reset, if the host can't communicate with it, it could do the same thing, and if the device thinks everything is fine but the host knows better, the host could order it to reset.
There are at least three APIs worth looking into for this problem: the Setup API, the Config Manager API, and various WMI extensions. However, be cautious about diving into WMI if you intend to use an Embedded XP target, as you will have to include a lot of other things in your OS image you might otherwise not need.
As far as I know, there is no way to do this - you can issue a command to have PnP rescan the bus for new devices, but that isn't the same as issuing a bus reset.
Furthermore, just because from a hardware perspective you issued a bus reset doesn't mean that Windows will remove the PDOs that represent the children of the hub and redetect them; the USB bus driver can (and does) do just what I describe (i.e. issue hardware bus resets without disturbing the device tree), and only after the device doesn't respond does it issue the surprise removal and yank it from the tree.
I need to create a application that will allow a Windows PC (XP/Vista) to emulate a thumbdrive. That is, when the PC is plugged into either another Windows system, or in this case, a piece of hardware that allows for USB thumbdrives to be plugged in, a folder on the computer looks like a giant thumbdrive. Any thoughts on where a guy would start to investigate this?
Update (more specific description):
I need to connect my PC to one of the newer multifuction devices that support scanning to a USB thumbdrive that is inserted into the front of the device. These units do not support WIA or TWAIN via the rear USB connector that you'd typically use for connectivity to a PC.
Most USB controllers in regular pc's dont have the possibility to function as an USB slave. So I'd start with investigating what kind of hardware you're going to use.
Another way to go: there are USB Link cables to link up 2 pc's over USB, maybe that's usable for you?
You cannot do this in an application. At the lowest level, the USB ports on your computer are controlled by an Host Controller Interface. This chip will manage up to 127 slave USB devices. You would need to seriously reprogram this chip before it implements the slave side of the USB protocol. Of course, at that point any USB hub in your PC will break down - those 8 USB ports you probably have are usually implemented by 2 smart USB hubs connecting to both USB1 and USB2 host controllers. Next, your USB keyboard and mouse will stop working.
Take an MCU with two Slave USBs. Write a simple frimware which makes one USB act as a Special Device Class and wait until PC on this USB provides mandatory data (including Device Class, of course) for the other USB. Write a PC program which connects to the Special Device (your MCU), uploads Mass Storage Device Class and redirects I/O to a dedicated partition. The other USB on the MCU will become an emulated Mass Storage Device.
Some of those code can be taken from Linux.