The DVD drive of my laptop is not functional altough Windows says that the driver is correctly installed.Indeed,I checked the behavior of the motors : the sledge motor is stuck on the same position (not translating) while the turn-table motor seems to be turning when inserting a CD/DVD (I can hear its sound for a lapse of time)...
As an old PlayStation player I know that this is a bad sign...My guess is that something is blocking the sledge motor...
I thought for a while that I could control programmatically the motors ( to check them) through the SCSI commands but I realized later that this interface does not offer such capabilities .Since motors and their position calculation may be even a matter of firmware and chip-sets,my next move now is to search for a more low level API - why not assembly language - to find a solution but I'm clueless and can't find documentation for such functionalities...
Did I miss something regarding the SCSI documentation or is there an existing API to control the CD drive motors ?
There is no WinAPI can achieve this.(Maybe in future)
Make sure that your CD/DVD is okay (whether the CD/DVD is corrupted, format is not supported, region restrictions).
Of course you can get the device status with DeviceIoControl and IOCTL_CDROM_CHECK_VERIFY(this IOCTL is replaced by IOCTL_STORAGE_CHECK_VERIFY according to the doc). You can find an example of how to retrieve it on Larry Osterman's blog.
Or you can try to use the mciSendString with Multimedia Command Strings(such
as play,step...).
Maybe all you need to do is dust your hardware.
Related
I am writing a USB driver and have a popup that contains specific information about the currently selected USB device.
However, I seem unable to find any way to determine the current power being used by the device. I can obtain the current power available on the port, but not the device itself.
There are API's to request extra power and to release it, but I can find nothing that tells me what the current power draw of the device is.
I know it is possible as other utilities can show this information, however, IOKit seems to lack the usual level of Apple documentation!
Is the "Requested Power" property on the IOUSBDevice node corresponding to the device of use to you? This is the value of the "bMaxPower" property in the configuration descriptor, i.e. the device's advertised maximum power consumption in 2mA units. Things get a little more complicated with USB3, the extra 400mA that can be made available to a superspeed device are recorded separately, and I think it's different again for the extra power supplied to iPods, iPhones, etc. which don't follow the USB3 spec. You'll need to check the IOUSBDevice source code for that, and maybe do some digging around with IORegistryExplorer.
I have read that USB HDD are hot-pluggable but not removable whereas USB Flash drives are both removable and hot-pluggable.Internally, the windows DEVICE_OBJECT structure has Characteristics flag that can have a value FILE_REMOVABLE_MEDIA for removable media (not the removable device). Also, STORAGE_HOTPLUG_INFO structure has Devicehotplug boolean member that says device is hot pluggable or not. Can you please justify your answer with a little details?
David Zeuthen explains it best:
[...] "removable" means that the media of the device is removable. For
example, CD-ROM drives or Nin1 card readers for flash media. [...]
ATA disks connected via eSATA aren't removable, you can't remove the
platters.
Yet of course, you can intuitively understand that even non-removable devices can be hotpluggable (i.e. you can plug and unplug the entire device as a whole, as opposed to inserting/removing the media it contains).
Now, all (modern) buses in use in current systems are hotpluggable -
most new systems allow you to add/remove SATA disks while the system
is running.
Indeed you shouldn't have to care much about whether something is hotpluggable or not anymore: virtually all storage devices are. (In the past, you had to shutdown the machine to manipulate the storage devices).
So, it should follow that external USB drives (either HDDs or flash sticks) for example should be non-removable and hopefully always hotpluggable.
Unfortunately:
Of course, hardware sucks so virtually all USB keyfobs reports
"removable==1" probably because the maker of the device wanted to be
"helpful" and make things work better on windows.
I have no sources regarding the real reasons, but it turns out that many USB drives report themselves as removable too. David's suggestion that it might be because of certain operating systems which didn't use to support hotplugging but did support removable devices (CD-ROMs, etc) sounds reasonable: the manufacturers reused the same technique to trick the OS into letting the user "eject" USB drives.
Nowadays I would guess all modern operating systems make the distinction clear, and this has many advantages from a management standpoint (e.g. you might have a hotpluggable DVD drive with removable DVDs and you would thus need to be more clear about which you want to interact with). Still, older drives and old habits die hard, so you'll still find some "removable" USB drives even if they're really not.
Note: The bug report linked is about udisks which is more often found in the free software world. But again, I'm sure all systems make the distinction now even if the terminology is not exactly the same. Also note that the terminology is really rather arbitrary, though whichever terms you use for these two concepts best be well understood.
A simple Google search could have answered your question...
Hot plugging is the ability to replace or install a device without shutting down the attached computer. Hot plugging is implemented when
a peripheral device is added or removed; a device or working system
requires reconfiguration; a defective component requires replacement
or a device and computer require data synchronization. Also known as hot swapping. Hot swapping
allows easy accessibility to equipment and the convenience of
uninterrupted systems.
Removable media are data storage devices capable of computer system removal without powering off the system. Removable media devices are
used for backup, storage or transportation of data.
source: techopedia dot com
I have been searching through how to do gamepad and joystick support on Mac for some days and all resources that I found seems to suggest a pre-installed driver along with using Apple's HID API, which works.
The drawback about this approach is that each joystick and gamepad will require another kernel extension to be loaded, so it can be recognized by HID manager, or at least a code less Info.plist saying it conforms to the earlier installed driver. For instance, when I have an 360 Xbox driver KEXT in house, the Xbox controller from Microsoft will work, but not the Logitech one (I tried F710).
As Apple suggests the application that uses a gamepad or joystick should be able to do themselves at user space without introducing any KEXT stuff. Is there a way to do it?
The thing I had in mind was something like using IORegistry or IOUSB API to get the device when they get plugged in (USB Prober shows it at least). Then somehow get the description of the device, then use that description to register the device as a HID one. Then the whole HID manager can be used.
Am I on the right track? Or is there any other way to do this?
Since IOKit API actually provided keywords like kHIDUsage_GD_Joystick, and there's an ForceFeedback.h library, I suppose Apple designed their HID API with joystick and force feedback in mind. That's the slim hope I had that this might work.
Some reference documentation and open source project:
Colin Munro's 360 driver
HID API Documents
DDHID Project
After revisiting this, I found out the solution to be operating directly on the file descriptors of the device. libusb is an excellent library which greatly simplify your life on this and they have Mac supported.
xboxdrv link is a great example on how to operate on file socket using libusb.
In pseudo code, it should look like this:
enumerate device
detect kernel driver and detach it if possible
open device
file off a initial transfer
wait on the callback function to handle msg and error properly
start run loop or select on fd to call libusb_event_handle
Check libusb for more info link.
i want to create a virtual monitor. The way this would work is that the virtual monitor would appear in a window on my desktop. As far as Windows knows it is just another monitor.
It occurs to me that it would, as a practical matter, have to be done as video card driver (i.e. rather than the video going out a wire to an LCD panel, it would go into another window on the desktop).
Does what i'm describing sound, technically, possible? (from a DDK point of view)
Note: i can't use a virtual pc, because no virtual PC has resolutions high enough for my needs. Also because it's not what i asked for.
Note: My reasons are unimportant, but i can make some up:
i want to test my application under high-dpi settings (288dpi)
i want to create a monitor that my iPad can VNC to
the family TV runs on the main monitor
the hijacker is monitoring the bus, and he'll blow it up if he suspects we're getting the passengers off
i'm trying to expand the limits of human knowledge and understanding, for the good of all man-kind
I'd say it's definitely possible, since that's what virtualization tools do for their guest utilities, but I wouldn't be able to tell you how in details. I'd suggest looking at the VirtualBox guest driver code as a starting point:
http://www.virtualbox.org/browser/trunk/src/VBox/Additions/WINNT/Graphics
(This is released under GPL as far as I'm aware.)
It's definitely possible, see for example the UltraVNC mirror driver. But I don't know of any virtual video driver that makes source code available.
I have been searching for something similar and I found a nice solution: spacedesk. You can download it here: http://spacedesk.ph/
In windows, it installs an extra monitor, which you can open in a browser or a viewer. Enjoy!
Don't know about Windows, but for X (Linux) there is Xvfb (X Virtual Frame Buffer), which is quite a useful thing.
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.