I need a bit more support. Per Apple’s guidance, our dext’s hosting app checks to see if the dext is installed, and if it is not installed, it will register the dext. I am going to refer to this as “auto registration.” I have also added a menu option to register the dext, which I am going to call “manual registration.” The manual registration works. The user is prompted to “Allow” the dext to be loaded, and things proceed normally. The auto-registration does not work. It produces an error response that is not helpful: Request did fail with Error 1 (The operation couldn’t be completed. (OSSystemExtensionErrorDomain error 1.)) Registration failed, unknown error. They execute the exact same code path – the auto registration calls the menu option’s function that executes from user selection. When comparing the sysextd logs, they differ starting at “Advancing from validating to validating_by_category.” The manual registration has a trace that reads: got reply from com.apple.system_extension.driver_extension... The auto registration does not get this reply. Attached are the two logs. This is Sonoma 14.7.6, the earliest OS we must support. Any suggestions on what is happening or how to fix it so that auto registration can work? Validate_by_category failure trace Validate_by_category success trace

Hi Kevin, I'm starting this new thread to focus on alignment optimization and recalibrating our HBA constraints. Following up on your suggestion about UserReportHBAConstraints and alignment optimization, here are our current DEXT settings: Via UserReportHBAConstraints(): kIOMaximumSegmentCountRead/WriteKey: 129 kIOMaximumSegmentByteCountRead/WriteKey: 65,536 (64 KB) kIOMinimumSegmentAlignmentByteCountKey: 4 bytes kIOMaximumSegmentAddressableBitCountKey: 32 kIOMinimumHBADataAlignmentMaskKey: 0 Via SetProperties() (additional injection): kIOMaximumByteCountRead/WriteKey: 524,288 (512 KB) kIOMaximumBlockCountRead/WriteKey: 1,024 We inherited the segment count (129) and max I/O length (512 KB) from our legacy KEXT, which were originally calculated based on a 4 KB segment size (Max I/O 512 KB / 4 KB + 1 = 129). The current alignment value of 4 was essentially a placeholder, as the legacy hardware didn't enforce strict page-level alignment. Given that our testing is on Apple Silicon, we are considering increasing kIOMinimumSegmentAlignmentByteCountKey to 16,384 (16 KB) to match the native page size. However, I have two specific questions regarding this: Stripe Size vs. Page Size: Our RAID stripe size is typically larger than 16 KB (e.g., 64 KB or 128 KB). Should we be aligning the system to the RAID stripe size for hardware efficiency, or is it more critical to stick to the 16 KB page size to optimize the IOMMU/DART mapping overhead in DriverKit? Recalibration: If we increase the alignment to 16 KB, should we also adjust the kIOMaximumSegmentByteCount to match (i.e., 16 KB), or is it better to keep it at 64 KB to allow fewer, larger segments per I/O? We suspect that the 38% gain we saw in 4 KB Random Reads might improve even further if we fix this alignment bottleneck. Looking forward to your thoughts. Best regards, Charles

On the Certificates, Identifiers and Profiles section of the Account section of developer.apple.com, if you manually configure the Capabilities of an App Identifier, there are icons with no tooltips. Does anyone know what they mean? (I'm particularly interested in the two different icons shown in my screenshot, with the same name)

One of the possible solutions to a problem that I'm working on is to have two Drivers loading in one DriverKit dext, an IOUserHIDEventService and an IOUserHIDDevice. For this to work, however, I need to have the event service send a message to the Device. IOKit has the service and connection objects that I can use just like an app would (just like the app the driver communication example). But DriverKit complains whenever I try to add the IOKit framework, saying that it is not supported. Is there another way that I can send a message directly from one driver to another?

Hi, We’re developing a DriverKit extension for iPadOS. In local Debug and Release builds, everything works as expected, but the same build uploaded to TestFlight fails at IOServiceOpen with the following errors: -536870212 (0xE00002EC) kIOReturnUnsupported -536870201 (0xE00002F7) kIOReturnNotPermitted What we’ve verified so far App entitlements We checked our main app entitlements file, and it has the correct capabilities for the driverkit communication <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>com.apple.developer.driverkit.communicates-with-drivers</key> <true/> <key>com.apple.developer.driverkit.userclient-access</key> <array> <string>abc.def.ABCDriver</string> </array> <key>com.apple.developer.system-extension.install</key> <true/> <key>com.apple.security.app-sandbox</key> <true/> <key>com.apple.security.device.usb</key> <true/> <key>com.apple.security.files.user-selected.read-write</key> <true/> </dict> </plist> we also checked the Provisioning profile (as shown on the portal) and the “Enabled Capabilities” seems to have the correct DriverKit Capabilities enabled. Enabled Capabilities Access Wi-Fi Information, DriverKit, DriverKit (development), DriverKit Communicates with Drivers, DriverKit USB Transport (development), DriverKit USB Transport - VendorID, DriverKit UserClient Access, iCloud, In-App Purchase, Sign In with Apple, System Extension When we download and inspect the provisioning profile as plain text, we notice that some expected DriverKit entitlements appear to be missing from the section. <key>Entitlements</key> <dict> <key>beta-reports-active</key> <true/> <key>com.apple.developer.networking.wifi-info</key> <true/> <key>com.apple.developer.driverkit</key> <true/> <key>com.apple.developer.driverkit.communicates-with-drivers</key> <true/> <key>application-identifier</key> <string>ABC123456.abc.def</string> <key>keychain-access-groups</key> <array> <string>ABC123456.*</string> <string>com.apple.token</string> </array> <key>get-task-allow</key> <false/> <key>com.apple.developer.team-identifier</key> <string>ABC123456</string> <key>com.apple.developer.ubiquity-kvstore-identifier</key> <string>ABC123456.*</string> <key>com.apple.developer.icloud-services</key> <string>*</string> <key>com.apple.developer.icloud-container-identifiers</key> <array></array> <key>com.apple.developer.icloud-container-development-container-identifiers</key> <array></array> <key>com.apple.developer.ubiquity-container-identifiers</key> <array></array> <key>com.apple.developer.driverkit.transport.usb</key> <array> <dict> <key>idVendor</key> <integer>1234</integer> </dict> </array> <key>com.apple.developer.applesignin</key> <array> <string>Default</string> </array> </dict> We have a couple of questions: Could the missing com.apple.developer.driverkit.userclient-access entitlement in the provisioning profile alone explain the kIOReturnUnsupported / kIOReturnNotPermitted failures from IOServiceOpen? Why do some DriverKit capabilities appear in the Apple Developer portal UI but vanish from the actual profile we download? Is there an extra step we’re overlooking when regenerating profiles after toggling those capabilities? Thanks

Hello everyone, I am currently working on an iPadOS application that requires communicating with a custom hardware board based on the Raspberry Pi RP2040 microcontroller via USB. My initial thought was to use the standard CDC-ACM (virtual serial port) profile on the RP2040. However, my understanding is that iPadOS's built-in system drivers will automatically claim any standard CDC-ACM interfaces, preempting my custom USBDriverKit driver from matching and taking control of the device. Is my assumption correct that iPadOS will strictly preempt a standard CDC-ACM device, making a custom DriverKit implementation impossible for that specific class?

Hello everyone, I am migrating a legacy KEXT to a DriverKit (DEXT) architecture. While the DEXT itself is working correctly, I am completely blocked by a code signing issue when trying to establish the UserClient connection from our SwiftUI management app. Project Goal & Status: Our DEXT (com.accusys.Acxxx.driver) activates successfully (systemextensionsctl list confirms [activated enabled]). The core functionality is working (diskutil list shows the corresponding disk device node). The Core Problem: The userclient-access Signing Error To allow the app to connect to the DEXT, the com.apple.developer.driverkit.userclient-access entitlement is required in the app's .entitlements file. However, as soon as this entitlement is added, the build fails. Both automatic and manual signing fail with the same error: `Provisioning profile ... doesn't match the entitlements file's value for the ... userclient-access entitlement.` This build failure prevents the generation of an .app bundle, making it impossible to inspect the final entitlements with codesign. What We've Confirmed: The necessary capabilities (like DriverKit Communicates with Drivers) are visible and enabled for our App ID on the developer portal. The issue persists on a clean system state and on the latest macOS Sequoia 15.7.1. Our Research and Hypothesis: We have reviewed the official documentation "Diagnosing issues with entitlements" (TN3125). According to the documentation, a "doesn't match" error implies a discrepancy between the entitlements file and the provisioning profile. Given that we have tried both automatic and manual profiles (after enabling the capability online), our hypothesis is that the provisioning profile generation process on Apple's backend is not correctly including the approved userclient-access entitlement into the profile file itself. The build fails because Xcode correctly detects this discrepancy. Our Questions: Did we misunderstand a step in the process, or is the issue not with the entitlement request at all? Alternatively, are there any other modifications we can make to successfully connect our App to the DEXT and trigger NewUserClient? Thank you for any guidance.

A signed DriverKit extension fails OSSystemExtensionRequest activation on macOS 26.4.1. The user-facing error is OSSystemExtensionErrorDomain code 4 ("Extension not found in App bundle") — but the dext is in the bundle, the identifier matches, and sysextd confirms it received the request: sysextd: [com.apple.sx:XPC] client activation request for com.arqitekta.bluefield.rshim.driver sysextd: attempting to realize extension with identifier com.arqitekta.bluefield.rshim.driver …and then nothing further. systemextensionsctl list reports 0 extensions. Question: Which log subsystem/category surfaces the kernel-side reason that sysextd aborts after "attempting to realize"? com.apple.sx only shows the request was accepted; whatever vetoes the realize step isn't in that subsystem (or isn't at info/debug level). Is there a separate predicate for the kernelmanagerd / dext-loading path I should be capturing? Environment: macOS 26.4.1 (25E253), Apple Silicon Mac Studio Xcode 26.2 (17C52), DriverKit SDK 25.2 SIP disabled, systemextensionsctl developer on Apple Developer Program, signed "Apple Development: …" DriverKit entitlement request 264CFJJU36 approved; profile includes com.apple.developer.driverkit, allow-any-userclient-access, transport.pci Already verified: Dext at Contents/Library/SystemExtensions/RshimDriver.dext CFBundleIdentifier matches the request, CFBundlePackageType=DEXT codesign --verify --deep --strict passes on app + dext embedded.provisionprofile parses, contains the expected entitlements Three IOKitPersonalities (BF2 / BF2-alt / BF3) using Apple's placeholder IOPCIPrimaryMatch Installer app entitled with com.apple.developer.system-extension.install only spctl -a -vv on the dext reports "rejected" — expected for development signing, should be bypassed under developer mode Minimal repro: https://github.com/jfabienke/bluefield-macos-toolkit/tree/dev-stub-entitlements/rshim-dext — build.sh produces the failing app dext. Captured artefacts (build output, embedded profile dump, signing report, repro shell script) under rshim-dext/dts-artifacts/. Looking for either (a) the right log show predicate to find the actual refusal reason, or (b) an environmental requirement on macOS 26 I'm missing.

Hello, I have crated a DriverKit driver for macOS and iPad M-series if I ever get the mac driver working. I have the correct entittlements, and matching provisioning profile downloaded manually. The driver loads (no errors!), and is visible in ioreg below the usb device (when plugged). The issue is that I never get any log from the driver, have reduced to minimal working code (below). When I debug with lldb, I load the symbols for my driver and break on init and Start - but lldb never triggers == never calls start or init. This is also why no logs. When I unplug the device, the driver process (ps aux) keeps running, causes a hard crash of the Mac with dext remove/or kill driver.dext process. I have asked Claude - but its just running in circles: check Info.plist=ok, check entitlements=ok, check code (minimal)=ok, check iig=ok, check provisioning profile=ok, check build settings=ok, check ioreg=ok, check code signature=ok, start over I don't get any log from my driver, which is consistent with init() not being called. All logs from kernel & friends (AMFI) do show the driver loading - no errors. Any tips appreciated! // USBDriver.iig #ifndef USBDriver_h #define USBDriver_h #include <USBDriverKit/IOUSBHostInterface.iig> class USBDriver: public IOService { public: virtual bool init() override; virtual void free() override; virtual kern_return_t Start(IOService * provider) override; virtual kern_return_t Stop(IOService * provider) override; }; // USBDriver.cpp #include <os/log.h> #include <DriverKit/DriverKit.h> #include "USBDriver.h" bool USBDriver::init() { if (!super::init()) return false; os_log(OS_LOG_DEFAULT, "terminal.driver: init()"); return true; } kern_return_t IMPL(USBDriver, Start) { os_log(OS_LOG_DEFAULT, "terminal.driver: Start()"); kern_return_t ret = super::Start(provider); if (ret != kIOReturnSuccess) { os_log(OS_LOG_DEFAULT, "terminal.driver: super::Start failed: 0x%08x", ret); return ret; } os_log(OS_LOG_DEFAULT, "terminal.driver: Start() success"); return super::Start(provider); } kern_return_t IMPL(USBDriver, Stop) { os_log(OS_LOG_DEFAULT, "terminal.driver: Stop()"); return super::Stop(provider); } void USBDriver::free() { os_log(OS_LOG_DEFAULT, "terminal.driver: free()"); super::free(); }

Hello! I have app (macos and iPadOS platforms) with empbedded DEXT. The DEXT executable runs fine on both platforms (ver 26.2). Trying to execute from iPad App code: let sysExtWs = OSSystemExtensionsWorkspace.shared let sysExts = try sysExtWs.systemExtensions(forApplicationWithBundleID: appBudleId) but always getting OSSystemExtensionError.Code.missingEntitlement error. Which entitlement am I missing? Thank You!

We are trying to determine whether a third-party DriverKit HID dext can seize or intercept raw HID input reports from an external mouse through any top case–related path in the HID stack. Our dext is based on IOUserHIDEventDriver, and the goal is to receive raw input reports before they are translated into higher-level pointer events. Apple’s public HIDDriverKit documentation describes IOUserHIDEventDriver as the driver object responsible for dispatching pointer, digitizer, scrolling, and related HID-originated events, but it is not clear to us whether any “top case” path is actually exposed or supported for third-party matching in DriverKit. What we want to clarify is specifically about external mouse devices, not the built-in trackpad itself. Questions: Is there any officially supported way for a third-party DriverKit HID dext to bind through a top case–related path and receive raw HID input reports from an external mouse? Is “top case” something that third-party DriverKit drivers can meaningfully target for matching/attachment, or is it only an internal Apple implementation detail? If such a path exists, can it be used to seize raw reports before they are converted into higher-level pointer events? If not, what is the officially supported boundary for third-party DriverKit access to raw reports from external mouse-class HID devices? To be clear, we are not asking about synthesizing pointer events. We are asking whether a third-party DriverKit dext can directly observe or seize the original HID input reports from an external mouse by attaching through any top case–related portion of the HID stack. If “top case” is not a public DriverKit concept that third parties can target, confirmation of that would also be very helpful.

We are trying to intercept raw reports from the built-in MacBook haptic trackpad using a DriverKit IOUserHIDEventDriver dext. Our dext installs and activates successfully: OSSystemExtensionRequest finishes with result 0 systemextensionsctl list shows the dext as activated enabled the dext is embedded correctly in the app bundle However, it never attaches to the built-in trackpad IOHIDInterface. ioreg shows the built-in trackpad interface still matched only by Apple’s HID dext. We also observed that Apple’s own HID dext appears to use com.apple.developer.driverkit.builtin, while that entitlement is not available in our provisioning profile. Our dext specifically relies on: IOUserHIDEventDriver::handleReport(...) SetProperties() with kIOHIDEventDriverHandlesReport Questions: Is com.apple.developer.driverkit.builtin required for a third-party IOUserHIDEventDriver to match a built-in internal trackpad IOHIDInterface? Is that entitlement public/requestable, or Apple-internal only? At what stage is it enforced: activation, personality matching, provider attach, or before Start()? If builtin is not available to third parties, is there any officially supported way to receive raw reports from the built-in MacBook trackpad in DriverKit? Our conclusion so far is that activation succeeds, but provider binding to the built-in trackpad fails due to built-in-only authorization/matching.

I'm in the process of writing a DriverKit USBHostInterface driver, and while I'm finally starting to get there, I've run into a bit of a frustration with logging. Naturally I have a liberal amount of os_log calls that I'm using to troubleshoot my driver. However I've noticed that they don't show up until after the first time my driver has loaded. Meaning, for example, suppose I make a new build of my driver and it's bundled user-mode app, install the bundle to /Applications, run the installer, verify it took with systemextensionsctl list, fire up Console and start streaming log entries, then plug in my device. I can see the log entries that show that my driver is loaded, etc., then a bunch of kernel -> log entries, but none of my Start method log entries. If I unplug my device and plug it in again, my log entries show up as expected. Why is this and, more importantly, how can I fix it? I'd like to see those log entries the first time the driver loads, if I could.

Trying to use IOLog to print out a message from a dext. When I try to use IOLog, I get , though I did not or thought I did not tag it as private. I have tried to update the info.plist file for the dext according to https://developer.apple.com/forums/thread/705810, but that has not helped, or perhaps I am not defining it correctly since it's a dext. Anyone else had this issue, and how did you fix it?

Hi Everyone, We are currently migrating a mature legacy KEXT to DriverKit for our PCIe SCSI storage controller (connected via Thunderbolt 3). During the DEXT load sequence, we have observed that the system automatically triggers a power state transition from State 0 (Off) to State 2 (On). However, this process results in a Kernel Panic due to a timeout after approximately 21 seconds. We have verified that our implementation of Start_Impl, UserInitializeController_Impl, and SetPowerState_Impl executes extremely fast, with a total execution time of less than one second. Specifically, SetPowerState_Impl returns kIOReturnSuccess immediately upon being called. Furthermore, our current Info.plist does not contain any IOPowerManagement dictionary or related keys. Despite the fast execution and the absence of explicit power management declarations in the plist, the kernel power management state machine (IOServicePM) still generates a 21-second timeout, leading to the following panic: Panic Log: panic(cpu 7 caller 0xfffffe0020be8fec): MySCSIDriver::setPowerState(0xfffffe2fb1a65c00 : 0xfffffe0020bfed88, 0 -> 2) timed out after 21257 ms @IOServicePM.cpp:5609 com.example.driver.dext: ( id: com.example.driver.dext; path: /Library/SystemExtensions/[UUID]/com.example.driver.dext; state: loaded ) Note on Previous Discussion: I would like to express my gratitude to Kevin from Apple DTS for the helpful discussion regarding the implementation of BundleParallelTask on the forums. Since then, we have shifted our development focus toward completing the overall management ecosystem, delivering a comprehensive operational interface for users, and handling specific user environments and behaviors. Our current priority is ensuring system stability—specifically resolving these Thunderbolt-related power management issues (sleep/wake)—to prepare the product for upcoming testing. I remain very grateful for the guidance provided on batch task optimization and intend to resume those optimizations once this critical stability baseline is secured. Technical Guidance Needed for PM Migration In our legacy KEXT, we utilized PMinit(), registerPowerDriver(), and joinPMtree() to precisely control the timing of power management registration. In transitioning to the DriverKit SDK, we have not found clear guidance on several key points: Standardized Migration Path: What is the recommended way to implement equivalent power management initialization (formerly PMinit) within a DriverKit subclass? In DriverKit, how should we replicate the behavior of manually calling registerPowerDriver and joinPMtree to ensure the driver is only monitored once the hardware is ready? Implicit Power Registration: Why does the system enforce a setPowerState(0 -> 2) transition on a subclass of IOUserSCSIParallelInterfaceController even when no IOPowerManagement dictionary is defined in the Info.plist? Is this a default behavior of the SCSI or PCI transport framework? Thunderbolt Specifics: Are there specific power proxying requirements or configurations for PCIe devices over Thunderbolt to avoid conflicts with the default IOPCIFamily power policies? Best Regards, Charles

My application will create a virtual touchpad. The problem I encountered is: click on the Product menu, select Archives, then select the Distribute App, then click on Drill Distribution, then click on Distribute, and then a prompt appears: Provisioning profile "Mac Team direct Provisioning Profile:"com.xxx.xxx"doesn't match the entitlements file's valuefor the com.apple.developer.driverkit.userclient-access entitlement. But My Identifiers Selected the:DriverKit Allow Any UserClient (development) Do I need toRequest a System Extension or DriverKit Entitlement Select "Virtual HID" in here? https://developer.apple.com/contact/request/system-extension/

I have a custom hardware board that I want to communicate serially with from an iPad. Should I use the DriverKit route or the MFi route?

I have a custom hardware board that I want to communicate serially with from an iPad. Should I use the DriverKit route or the MFi route?

While I welcome the arrival of a userspace implementation of drivers, DriverKit as it stands has some notable flaws. My main concern is the ability of open-source projects like HoRNDIS being able to access paid developer accounts and the limited entitlement scope (plus the waiting period) for what is essentially a hobbyist free project. Even if the developer is a professional company, some legacy hardware will go unsupported because of a lack of support from the vendor. Providing a way for users who need access to older hardware would be needed. Three concrete requests: A class-level or wildcard VID/PID entitlement for open source projects with a verifiable public repository A free or reduced-cost entitlement path for non-commercial volunteer-maintained drivers Published approval criteria and timelines so projects can plan accordingly Depreciating kexts without providing an accessible successor for community projects isn't security, it is gatekeeping access to hardware that is critically needed. Is this use case on the roadmap at all? Developers deserve a clear answer.

Hello, I'm trying to develop a driver that uses PCIe through the mac's thunderbold ports. I requested a PCI entitlement, and it's just an empty array in the entitlements file by default. I was wondering if the vendor ID submitted with my entitlement request is supposed to populate this dictionary? I'm currently getting an entitlement check failed from kernel: DK: IOUserServer and was unsure if the PCI entitlement configuration was incorrect. Default entitlement: <key>com.apple.developer.driverkit.transport.pci</key> <array> </array> I'd be happy to provide more information as needed, but any guidance would be much appreciated. Thanks in advance.