> > >in fact DeviceIOControl is used in two completly separate ways: >1/ control VxD >2/ control "device" handles on specific types > >the control on VxD is needed for Win 9x support. In that case the HIWORD >of the iocontrol code is always 0. So, in that case, a lookup is made in >the list of known VxD:s if wae can handle the request. > Ok. I read the "Calling DeviceIoControl on Windows 95/98/Me" MSDN page, and I now understand what it's about.
>the control on "device" handles is done when the high word of the >control code is non 0. > >as of today (but it's a bit hacky) handles to "device" and VxD:s are >viewed (in the server) as very simple objects. They only provide a > >clientID (a DWORD). all the calls to DeviceIOControl start by getting > >this client ID. > >If the value has the bit 0x10000 set, it means it's a VxD. The low word >of the client id then identifies the standard ID of the VxD. > You're refering to both VxDs and WDM (.sys) drivers, right ? How does the server find the correct low word of the client ID ? The driver I want to implement has a device type of 0xef00 (value passed to IoCreateDevice). I added a field to the VxD table with id set to 0xef00. Does wine, when I call CreateFile( "\\\\.\\MyDevice", ... ), check that table and set the client ID low word to the proper value ? >If the 0x20000 bit is set, it's in fact a handle a device. Driver A: >through Z: are mapped to 0 to 25 values (in the low word) > >Otherwise, it's a handle to the old DOS named devices (with their old >IDs too) > I think we should handler those cases in a new device handler (which would just test if the device is a CDROM for now). >So, back to DeviceIoControl when the high word of the io control code is >0. We expect device handle in that case (but don't test the 0x20000 bit for >error reporting), and then try to check if the device (from it's driver >letter) is a CDROM, and if so apply the io control on it. Support of io > >control on other types of device (hard disks, storage...) isn't done at the moment. > You mean when the high word is not 0, right ? I'll add a check for the 0x10000 and 0x20000 bits, and will dispatch the call to either a VxD or a device handler. Is that ok ?Can I use the same VxD list as for (HIWORD(dwIoControlCode) == 0 ) ? Laurent Pinchart
