I'm posting this here after reading Quinn's post here: https://developer.apple.com/forums/thread/799000
The above entitlement is mentioned in IOUSBHostControllerInterface.h.
It isn't an entitlement one can add using the + button on the Capabilities panel in Xcode. If I try to add it by hand, Xcode complains that it isn't in my profile.
Is this a managed entitlement?
We'd like to create a local USB "device" to represent a real device reachable over a network.
Selecting any option will automatically load the page
Post
Replies
Boosts
Views
Activity
I built an app which hosts a CMIOExtension. The app works, and it can activate the extension. The extension loads in e.g. Photo Booth and shows the expected video (a white horizontal line which moves down the picture).
I have a couple of questions about this though.
The sample Camera Extension is built with a CMIOExtension dictionary with just one entry, CMIOExtensionMachServiceName which is $(TeamIdentifierPrefix)$(PRODUCT_BUNDLE_IDENTIFIER)
This Mach service name won't work though. When attempting to activate the extension, sysextd says that the extensions has an invalid mach service name or is not signed, the value must be prefixed with one of the App Groups in the entitlement.
So in order to get the sample extension to activate from my app, I have to change its CMIOExtensionMachServiceName to
<my team ID>.com.mycompany.my-app-group.<myextensionname>
Is this to be expected?
The template CMIOExtension generates its own video using a timer. My app is intended to capture video from a source, filter that video, then feed it to the CMIOExtension, somehow. The template creates an app group called "$(TeamIdentifierPrefix)com.example.app-group", which suggests that it might be possible to use XPC to send frames from the app to the extension.
However, I've been unable to do so. I've used
NSXPCConnection * connection = [[NSXPCConnection alloc] initWithMachServiceName:, using the CMIOExtensionMachServiceName with no options and with the NSXPCConnectionPrivileged option. I've tried NSXPCConnection * connection = [[NSXPCConnection alloc] initWithServiceName: using the extension's bundle identifier. In all cases when I send the first message I get an error in the remote object proxy's handler:
Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named <whatever name I try> was invalidated: failed at lookup with error 3 - No such process."
According to the "Daemons and Services Programming Guide" an XPC service should have a CFBundlePackageType of XPC!, but a CMIOExtension is of type SYSX. It can't be both.
Does the CMIOExtension loading apparatus cook up a synthetic name for the XPC service, and if so, what is it? If none, how is one expected to get pixel buffers into the camera extension?
I have an app with a dext, which I developed using Xcode 13.4.1. I used to sign it manually using our Developer ID Distribution certificate and profile, because Xcode 13 didn't support automatic dext signing, and most of my problems stemmed from signing or entitlement configuration problems, not coding problems, so I never used 'sign to run locally'.
I tried to build the same app & extension with Xcode 14; the build fails with this helpful error:
Xcode 14 and later requires a DriverKit development profile enabled for IOS and macOS. Visit the developer website to create or download a DriverKit profile
So I went to the portal, selected the DriverKit App Development profile type, selected my App ID, selected my development certificate, selected all my test devices, selected my entitlements, named it, clicked Generate - and nothing happens. The "Generate" button title briefly changes to "Processing...", but I can't see how to get to the Download stage.
Anyone have any idea what I'm doing wrong?
Topic:
Developer Tools & Services
SubTopic:
Xcode
Tags:
Xcode
Provisioning Profiles
Signing Certificates
DriverKit
I'm trying to build the DriverKit template driver target in an Xcode project which contains an app targeting iPadOS 17. I've made no modifications to the DriverKit template.
When building, I get this link error
ld: file cannot be open()ed, errno=2 path=/Applications/Xcode 15.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/15.0.0/lib/darwin/libclang_rt.profile_driverkit.a in '/Applications/Xcode 15.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/15.0.0/lib/darwin/libclang_rt.profile_driverkit.a'
anyone know how to fix this? My search turned up something about building llvm from sources, which seems like overkill to put a DriverKit driver into an iPad app.
The presentation "create audio drivers with DriverKit" from WWDC 2021 demonstrates how to use a dext to implement a virtual audio driver. It also says " If a virtual audio driver or device is all that is needed, the audio server plug-in driver model should continue to be used".
Indeed, in AudioDriverKit/AudioDriverKitTypes.h, there is no IOUserAudioTransportType Virtual, although CoreAudio/AudioHardwareBase.h includes kAudioDeviceTransportTypeVirtual.
For one of our products, we require virtual devices to implement a software loopback "cable". We've implemented this using the "traditional" HAL plugin, and as a proof-of-concept, also using a dext. In the dext, I tried setting the transport type to 'virt', which seems to only have the effect of changing the icon shown in Audio Midi Setup.
HAL plugins require an installer, and the installer has to kill coreaudiod in a post-install script. You have to turn off SIP to debug them. Just like AudioDriverKit drivers, they are out-of-process and run in a process not owned by the hosting app. Our HAL plugin's interface is property based; we had to write a lot of boiler-plate code to implement required properties. Writing an AudioDriverKit driver is in most respects easier - a lot of the scaffolding is implemented in the base driver, which we only alter where required. Debugging and installation is much easier.
The dext works just fine, as far as we can ascertain, just as well as a HAL plugin.
So, my question is - is the advice to use a HAL plugin for a virtual device still correct in 2025? And if so, what's the objection? We'd really prefer to ship the AudioDriverKit virtual audio device.
I've made a dext and a user client that overrides IOUserSCSIPeripheralDeviceType00, with the object of writing device firmware to the driver. I can gain and relinquish exclusive access to the device, I can call UserReportMediumBlockSize and get back a sensible answer (512).
I can build command parameters with the INQUIRY macro from IOUserSCSIPeripheralDeviceHelper.h and send that command successfully using UserSendCB, and I receive sensible-looking Inquiry data from the device.
However, what I really want to do is send a WriteBuffer command (opcode 0x3B), and that doesn't work. I have yet to put a bus analyzer on it, but I don't think the command goes out on the bus - there's no valid sense data, and the error returned is 0xe00002bc, or kIOReturnError, which isn't helpful.
This is the code I have which doesn't work.
kern_return_t driver::writeChunk(const char * buf, size_t atOffset, size_t length, bool lastOne)
{
DebugMsg("writeChunk %p at %ld for %ld", buf, atOffset, length);
SCSIType00OutParameters outParameters;
SCSIType00InParameters response;
memset(&outParameters, 0, sizeof(outParameters));
memset(&response, 0, sizeof(response));
SetCommandCDB(&outParameters.fCommandDescriptorBlock,
0x3B, // byte 0, opcode WriteBuffer command
lastOne ? 0x0E : 0x0F, // byte 1 mode: E=save deferred, F = download and defer save
0, // byte 2 bufferID
(atOffset >> 16), // byte 3
(atOffset >> 8), // byte 4
atOffset, // byte 5
(length >> 16), // byte 6
(length >> 8), // byte 7
length, // byte 8
0, // control, byte 9
0, 0, 0, 0, 0, 0); // bytes 10..15
outParameters.fLogicalUnitNumber = 0;
outParameters.fBufferDirection = kIOMemoryDirectionOut;
outParameters.fDataTransferDirection = kSCSIDataTransfer_FromInitiatorToTarget;
outParameters.fTimeoutDuration = 1000; // milliseconds
outParameters.fRequestedByteCountOfTransfer = length;
outParameters.fDataBufferAddr = reinterpret_cast<uint64_t>(buf);
uint8_t senseBuffer[255] = {0};
outParameters.fSenseBufferAddr = reinterpret_cast<uint64_t>(senseBuffer);
outParameters.fSenseLengthRequested = sizeof(senseBuffer);
kern_return_t retVal = UserSendCDB(outParameters, &response);
return retVal;
}
The "deployment target" for a DEXT is a number like 19.0 or 21.4. Xcode seems to pick the latest version on the machine you are creating the target on as a default - so if I make a new Driver target on Xcode 14 and Ventura, the Deployment Target for the driver will be 21.4. If I'm targeting macOS 12 (for example), what version of DriverKit should I choose, and where is this documented?
I have a macOS app which contains a dext. I'd like to distribute it to external testers using TestFlight, so it has to pass Mac App Store review. It failed, because the App Sandbox entitlement was missing.
I checked the app, it has the entitlement, but the dext does not. However, the .entitlements file used by the dext does contain App Sandbox set to true.
I tried adding a "fake-entitlement" value to the .entitlements file, and that made it into the dext's code signature, but the App Sandbox entitlement appears to be stripped out by the build process?
For a dext target, it isn't possible to add the App Sandbox capability in Xcode's Signing and Capability section. I have to add the entitlement manually in the .entitlement file (or it was put there by the Xcode driver template, I don't remember).
I've tried clean building several times, I've tried Xcode 15.0.1, 15.2 and 15.3, but the result is always the same. I'm inspecting the entitlements using
codesign -dvvv --entitlements -
Does anyone know what I can do to put the App Sandbox entitlement into my dext's signature? Is this happening to anyone else?
I'm trying to implement an app Shortcut (Custom Intent) for a macOS app on Monterey. Shortcuts.app finds the shortcut, but when I run it, the progress bar goes to 50% and stops. My handler and resolution code is not called. I'm implementing the handling in-app (not in an extension)
I'm following instructions from the WWDC 2021 video "Meet Shortcuts for macOS" and this link https://developer.apple.com/documentation/sirikit/adding_user_interactivity_with_siri_shortcuts_and_the_shortcuts_app?language=objc
If I filter on "shortcuts" in the Console app, and press the run button in Shortcuts.app for my Shortcut,
I see this message (amongst others)
-[WFAction processParameterStates:withInput:skippingHiddenParameters:askForValuesIfNecessary:workQueue:completionHandler:]_block_invoke Action <WFHandleCustomIntentAction: 0x15c1305b0, identifier: finished processing parameter states. Values:
which looks sort of promising
but I also see this
Sandbox: Shortcuts(9856) deny(1) file-read-data /Users/stu/Library/Developer/Xcode/DerivedData/-hghdaydxzeamopexvfsgfeuvsejw/Build/Products/Debug/.app
I've tried moving my app to /Applications and launching it from there, I see a similar message in the log, but the path leads to the app in /Applications.
I've tried deleting all copies of my app aside from the one I'm currently building and debugging. I've tried deleting the derived data folder, restarting the Mac, re-launching the Shortcuts app. I've tried sandboxing my app. Other Shortcuts (for other apps) work on this machine.
I'm probably missing something extremely simple - does anyone have a suggestion?
Some related questions:
At WWDC 2022, Apple introduced "App Intents", without adequately explaining how these differ from the intents described in the WWDC 2021 video. Can anyone tell me what the difference is?
In the Xcode editor for the .intentdefinition file, there's a button "Convert to App Intent". Clicking it produces some new Swift files in my app, but the thing is an intent handled by an app, and now it is an App Intent - what's the difference? Is one better than the other? Do I have to click the convert button again if I subsequently modify the .intentdefinition file, or is this conversion process intended to replace the .intentdefinition file with those .swift files?