Thanks Rolf (and Uwe).
I did some further investigation and it looks like CreateFile (actually CreateFileW) looks at the filename and if it starts with "\." it calls DEVICE_Open(). DEVICE_Open() compares the file name (without the "\." ) against all the entries in VxDList[] and if there is a match it returns a handle based on the appropriate entry in VxDList[].
Let's say I add and entry in VxDList[] like this:
{ "MYDEVICE", 0x1234, NULL, DeviceIo_MyDevice },
If I call CreateFile("\\.\MyDevice0", ...), I will get back a handle based on the entry above. If I call CreateFile("\\.\MyDevice1", ...), I will get back another handle based on the entry above. But, when DeviceIo_MyDevice is called I will not be able to tell if this is the first or the second device.
of course I could add:
{ "MYDEVICE0", 0x1234, NULL, DeviceIo_MyDevice0 }, { "MYDEVICE1", 0x1234, NULL, DeviceIo_MyDevice1 }, . . . { "MYDEVICE256", 0x1234, NULL, DeviceIo_MyDevice256 },
There has to be a better way of doing this. How does this work for, let's say, a USB game controller?
Thanks,
Dan
On Wednesday, December 10, 2003, at 10:22 AM, Rolf Kalbermatter wrote:
Message: 2 Date: Tue, 9 Dec 2003 14:56:16 -0800 Subject: Adding support for a USB device From: Dan Timis timis@museresearch.com To: wine-devel@winehq.org
Hi,
I need help with supporting a particular USB device under wine. I have to start by saying that although I am an experienced C/C++ programmer with some Linux experience, I have almost no Windows or wine experience.
The Windows code for which I need to provide support uses CreateFile() to get a handle to the device. The name of the device is something like "\.\MyDevice0" "\.\MyDevice1" and so on. Then, the code uses DeviceIoControl() to read and write from/to the device. The requirement is not to change the windows code.
I looked through the wine code and I found this in device.c:
static const struct VxDInfo VxDList[]
I could add another entry into the table and write a deviceio handler (BOOL (*deviceio)(DWORD, LPVOID, DWORD, LPVOID, DWORD, LPDWORD, LPOVERLAPPED);). I wrote some test code in Linux using libusb reading and writing to the device so I know what to do inside the deviceio handler.
Is this the right approach? If so, what do I need to do to get CreateFile to return the right handle?
I think it really depends on the type of device and the possibility to rewrite the device driver or not.
\.\MyDevice0 is just a device driver name which at some point is registered in the registry with the appropriate VXD, SYS, or WDM driver file. If you know the exact DeviceIOControls called into that driver with its parameters and all, you could rewrite the VXD, SYS or WDM driver to call directly the appropriate Unix device driver calls and maybe compile it as a Winelib driver. With a bit hacking in the CreateFile function it should be possible to call such a driver over DeviceIOControl or you could add the according code to the above mentioned VXDList.
Or should I write an external driver that gets loaded by wine? If so, how would I do that? What are the chances that the Windows driver for this device would just work with wine?
If you don't know these details and want to use the original device driver you are probably out of luck. The current CreateFile implementation is not really up to the task of loading an external native device driver and invoke it over the DeviceIOControl (which could probably be remedied with a little hacking at this point) and what is much more problematic there is little or no support for a lot of the Windows kernel services most device driver usually expect to be able to call. When they are not able to link to one or more of those functions at load time, loading of the device driver will simply fail in Wine, as it does with normal DLL files under all Win32 implementations, too.
Rolf Kalbermatter