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Problem with DriverKitUserClientSample
First time working with DEXT, so I'm trying to make "Communicating between a DriverKit extension and a client app" sample project to work and I'm having trouble. I'm following the steps for "Automatically manage signing". It seems that the step “Sign to Run Locally” is wrong now, so I let it to Apple Developer. Now I have a Provisioning Profile error that says it doesn't include the com.apple.developer.driverkit.allow-any-userclient-access entitlement. If I go to Certificates, Identifiers and Profiles for this AppID and go to Capability Requests and select DriverKit Allow Any UserClient Access, this bring me to a page where I select DriverKit Entitlement but Any UserClient Access is not a choice. I tried asking for UserClient Access but the request has been denied saying that the engineering team does not think these entitlements are necessary for testing locally. So I removed com.apple.developer.driverkit.allow-any-userclient-access from NullDriver.entitlements. I can now install the DEXT but when I try "Communicate with Dext" button, I received the error: Failed opening connection to dext with error: 0xe00002e2. Looking in the console, I see this error message: DK: NullDriverUserClient-0x10000ad6a:UC failed userclient-access check, needed bundle ID com.example.apple-samplecode.dext-to-user-client-2-TEST.driver I tried many things, but I can't seem to be able to pass through the check to allow the application to communicate with the dext. What am I missing? Note that I'm focusing only on macOS, not iOS. Thanks.
7
0
243
Nov ’25
System Panic with IOUserSCSIParallelInterfaceController during Dispatch Queue Configuration
Hello everyone, We are in the process of migrating a high-performance storage KEXT to DriverKit. During our initial validation phase, we noticed a performance gap between the DEXT and the KEXT, which prompted us to try and optimize our I/O handling process. Background and Motivation: Our test hardware is a RAID 0 array of two HDDs. According to AJA System Test, our legacy KEXT achieves a write speed of about 645 MB/s on this hardware, whereas the new DEXT reaches about 565 MB/s. We suspect the primary reason for this performance gap might be that the DEXT, by default, uses a serial work-loop to submit I/O commands, which fails to fully leverage the parallelism of the hardware array. Therefore, to eliminate this bottleneck and improve performance, we configured a dedicated parallel dispatch queue (MyParallelIOQueue) for the UserProcessParallelTask method. However, during our implementation attempt, we encountered a critical issue that caused a system-wide crash. The Operation Causing the Panic: We configured MyParallelIOQueue using the following combination of methods: In the .iig file: We appended the QUEUENAME(MyParallelIOQueue) macro after the override keyword of the UserProcessParallelTask method declaration. In the .cpp file: We manually created a queue with the same name by calling the IODispatchQueue::Create() function within our UserInitializeController method. The Result: This results in a macOS kernel panic during the DEXT loading process, forcing the user to perform a hard reboot. After the reboot, checking with the systemextensionsctl list command reveals the DEXT's status as [activated waiting for user], which indicates that it encountered an unrecoverable, fatal error during its initialization. Key Code Snippets to Reproduce the Panic: In .iig file - this was our exact implementation: class DRV_MAIN_CLASS_NAME: public IOUserSCSIParallelInterfaceController { public: virtual kern_return_t UserProcessParallelTask(...) override QUEUENAME(MyParallelIOQueue); }; In .h file: struct DRV_MAIN_CLASS_NAME_IVars { // ... IODispatchQueue* MyParallelIOQueue; }; In UserInitializeController implementation: kern_return_t IMPL(DRV_MAIN_CLASS_NAME, UserInitializeController) { // ... // We also included code to manually create the queue. kern_return_t ret = IODispatchQueue::Create("MyParallelIOQueue", kIODispatchQueueReentrant, 0, &ivars->MyParallelIOQueue); if (ret != kIOReturnSuccess) { // ... error handling ... } // ... return kIOReturnSuccess; } Our Question: What is the officially recommended and most stable method for configuring UserProcessParallelTask_Impl() to use a parallel I/O queue? Clarifying this is crucial for all developers pursuing high-performance storage solutions with DriverKit. Any explanation or guidance would be greatly appreciated. Best Regards, Charles
21
0
863
Feb ’26
INQUIRY command is ILLEGAL REQUEST
I am developing a DriverKit driver with the goal of sending vendor-specific commands to a USB storage device. I have successfully created the DriverKit driver, and when I connect the USB storage device, it appears correctly in IORegistryExplorer. My driver class inherits from IOUserSCSIPeripheralDeviceType00 in the SCSIPeripheralsDriverKit framework. I also created a UserClient class that inherits from IOUserClient, and from its ExternalMethod I tried sending an INQUIRY command as a basic test to confirm that command transmission works. However, the device returns an ILLEGAL REQUEST (Sense Key 0x5 / ASC 0x20). Could someone advise what I might be doing wrong? Below are the logs output from the driver: 2025-11-14 21:00:43.573730+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] Driver - NewUserClient() - Finished. 2025-11-14 21:00:43.573733+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - Start() 2025-11-14 21:00:43.573807+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - Start() - Finished. 2025-11-14 21:00:43.574249+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - ExternalMethod() called 2025-11-14 21:00:43.574258+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - ----- SCSICmdINQUIRY ----- 2025-11-14 21:00:43.574268+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - command.fRequestedByteCountOfTransfer = 512 2025-11-14 21:00:43.575980+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB fCompletionStatus = 0x0 2025-11-14 21:00:43.575988+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB fServiceResponse = 0x2 2025-11-14 21:00:43.575990+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB fSenseDataValid = 0x1 2025-11-14 21:00:43.575992+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB VALID_RESPONSE_CODE = 0x70 2025-11-14 21:00:43.575994+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB SENSE_KEY = 0x5 2025-11-14 21:00:43.575996+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB ADDITIONAL_SENSE_CODE = 0x20 2025-11-14 21:00:43.575998+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB ADDITIONAL_SENSE_CODE_QUALIFIER = 0x0 Here is the UserClient class: class SampleDriverKitUserClient: public IOUserClient { public: virtual bool init(void) override; virtual kern_return_t Start(IOService* provider) override; virtual kern_return_t Stop(IOService* provider) override; virtual void free(void) override; virtual kern_return_t ExternalMethod( uint64_t selector, IOUserClientMethodArguments* arguments, const IOUserClientMethodDispatch* dispatch, OSObject* target, void* reference) override; void SCSICmdINQUIRY(SampleDriverKitDriver *driver) LOCALONLY; }; Here is the part that sends the INQUIRY command: void SampleDriverKitUserClient::SCSICmdINQUIRY(SampleDriverKitDriver *driver) { kern_return_t kr = KERN_SUCCESS; SCSIType00OutParameters command = {}; UInt8 dataBuffer[512] = {0}; SCSI_Sense_Data senseData = {0}; Log("----- SCSICmdINQUIRY -----"); SetCommandCDB(&command.fCommandDescriptorBlock, 0x12, 0x00, 0x00, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00); command.fLogicalUnitNumber = 0; command.fTimeoutDuration = 10000; // milliseconds command.fRequestedByteCountOfTransfer = sizeof(dataBuffer); Log("command.fRequestedByteCountOfTransfer = %lld", command.fRequestedByteCountOfTransfer); command.fBufferDirection = kIOMemoryDirectionIn; command.fDataTransferDirection = kSCSIDataTransfer_FromTargetToInitiator; command.fDataBufferAddr = reinterpret_cast<uint64_t>(dataBuffer); command.fSenseBufferAddr = reinterpret_cast<uint64_t>(&senseData); command.fSenseLengthRequested = sizeof(senseData); if( driver ) { SCSIType00InParameters response = {}; kr = driver->UserSendCDB(command, &response); if( kr != KERN_SUCCESS ) { Log("SCSICmdINQUIRY() UserSendCDB failed (0x%x)", kr); return; } Log("SCSICmdINQUIRY() UserSendCDB fCompletionStatus = 0x%x", response.fCompletionStatus); Log("SCSICmdINQUIRY() UserSendCDB fServiceResponse = 0x%x", response.fServiceResponse); Log("SCSICmdINQUIRY() UserSendCDB fSenseDataValid = 0x%x", response.fSenseDataValid); Log("SCSICmdINQUIRY() UserSendCDB VALID_RESPONSE_CODE = 0x%x", senseData.VALID_RESPONSE_CODE); Log("SCSICmdINQUIRY() UserSendCDB SENSE_KEY = 0x%x", senseData.SENSE_KEY); Log("SCSICmdINQUIRY() UserSendCDB ADDITIONAL_SENSE_CODE = 0x%x", senseData.ADDITIONAL_SENSE_CODE); Log("SCSICmdINQUIRY() UserSendCDB ADDITIONAL_SENSE_CODE_QUALIFIER = 0x%x", senseData.ADDITIONAL_SENSE_CODE_QUALIFIER); if( response.fServiceResponse == kSCSIServiceResponse_TASK_COMPLETE ) { Log("SCSICmdINQUIRY() UserSendCDB complete success!!"); } for( int i=0; i < 5; i++ ) { Log("data [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x", i*8+0, dataBuffer[i*8+0], i*8+1, dataBuffer[i*8+1], i*8+2, dataBuffer[i*8+2], i*8+3, dataBuffer[i*8+3], i*8+4, dataBuffer[i*8+4], i*8+5, dataBuffer[i*8+5], i*8+6, dataBuffer[i*8+6], i*8+7, dataBuffer[i*8+7] ); } char vendorID[9] = {0}; memcpy(vendorID, &dataBuffer[8], 8); Log("vendorID = %s",vendorID); char productID[17] = {0}; memcpy(productID, &dataBuffer[16], 16); Log("productID = %s",productID); } } My environment is: MacBook Pro (M2), macOS 15.6 If anyone has insight into what causes the ILLEGAL REQUEST, or what I am missing when using IOUserSCSIPeripheralDeviceType00 and UserSendCDB, I would greatly appreciate your help. Thank you.
1
0
325
Nov ’25
The total DMA size in DriverKit cannot exceed 2G?
We are developing a DriverKit driver on Apple M1. We use the following code to prepare DMA buffer: IODMACommandSpecification dmaSpecification; bzero(&dmaSpecification, sizeof(dmaSpecification)); dmaSpecification.options = kIODMACommandSpecificationNoOptions; dmaSpecification.maxAddressBits = p_dma_mgr->maxAddressBits; kret = IODMACommand::Create(p_dma_mgr->device, kIODMACommandCreateNoOptions, &dmaSpecification, &impl->dma_cmd ); if (kret != kIOReturnSuccess) { os_log(OS_LOG_DEFAULT, "Error: IODMACommand::Create failed! ret=0x%x\n", kret); impl->user_mem.reset(); IOFree(impl, sizeof(*impl)); return ret; } uint64_t flags = 0; uint32_t segmentsCount = 32; IOAddressSegment segments[32]; kret = impl->dma_cmd->PrepareForDMA(kIODMACommandPrepareForDMANoOptions, impl->user_mem.get(), 0, 0, // 0 for entire memory &flags, &segmentsCount, segments ); if (kret != kIOReturnSuccess) { OSSafeReleaseNULL(impl->dma_cmd); impl->user_mem.reset(); IOFree(impl, sizeof(*impl)); os_log(OS_LOG_DEFAULT, "Error: PrepareForDMA failed! ret=0x%x\n", kret); return kret; } I allocated several 8K BGRA video frames, each with a size of 141557760 bytes, and prepared the DMA according to the method mentioned above. The process was successful when the number of frames was 15 or fewer. However, issues arose when allocating 16 frames: Error: PrepareForDMA failed! ret=0xe00002bd By calculating, I found that the total size of 16 video frames exceeds 2GB. Is there such a limitation in DriverKit that the total DMA size cannot exceed 2GB? Are there any methods that would allow me to bypass this restriction so I can use more video frame buffers?
1
0
145
Dec ’25
MacOS(Apple Silicon) IOKit driver for FPGA DMA transmission, kernel panic.
MacOS(Apple Silicon) IOKit driver for FPGA DMA transmission, kernel panic. Hardware and software configuration: MAC mini M1 2020 16GB, macOS Ventura 13.0 or 13.7.8 FPGA device capability: 64-bit Complete description: We've developed a DMA driver for PCIe devices (FPGA) based on IOKit. The driver can start normally through kextload, and the bar mapping, DMA registers, etc. are all correct. I am testing DMA data transmission, but a kernel panic has occurred. The specific content of the panic is as follows: {"bug_type":"210","timestamp":"2026-01-28 14:35:30.00 +0800","os_version":"macOS 13.0 (22A380)","roots_installed":0,"incident_id":"61C9B820-8D1B-4E75-A4EB-10DC2558FA75"} { "build" : "macOS 13.0 (22A380)", "product" : "Macmini9,1", "socId" : "0x00008103", "kernel" : "Darwin Kernel Version 22.1.0: Sun Oct 9 20:14:30 PDT 2022; root:xnu-8792.41.9~2/RELEASE_ARM64_T8103", "incident" : "61C9B820-8D1B-4E75-A4EB-10DC2558FA75", "crashReporterKey" : "6435F6BD-4138-412A-5142-83DD7E5B4F61", "date" : "2026-01-28 14:35:30.16 +0800", "panicString" : "panic(cpu 0 caller 0xfffffe0026c78c2c): "apciec[pcic0-bridge]::handleInterrupt: Request address is greater than 32 bits linksts=0x99000001 pcielint=0x02220060 linkcdmsts=0x00000000 (ltssm 0x11=L0)\n" @AppleT8103PCIeCPort.cpp:1301\nDebugger message: panic\nMemory ID: 0x6\nOS release type: User\nOS version: 22A380\nKernel version: Darwin Kernel Version 22.1.0: Sun Oct 9 20:14:30 PDT 2022; root:xnu-8792.41.9~2/RELEASE_ARM64_T8103\nFileset Kernelcache UUID: C222B4132B9708E5E0E2E8B8C5896410\nKernel UUID: 0BFE6A5D-118B-3889-AE2B-D34A0117A062\nBoot session UUID: 61C9B820-8D1B-4E75-A4EB-10DC2558FA75\niBoot version: iBoot-8419.41.10\nsecure boot?: YES\nroots installed: 0\nPaniclog version: 14\nKernelCache slide: 0x000000001d1b4000\nKernelCache base: 0xfffffe00241b8000\nKernel slide: 0x000000001e3f8000\nKernel text base: 0xfffffe00253fc000\nKernel text exec slide: 0x000000001e4e0000\nKernel text exec base: 0xfffffe00254e4000\nmach_absolute_time: 0x907c3082\nEpoch Time: sec usec\n Boot : 0x6979adbb 0x00023a6a\n Sleep : 0x00000000 0x00000000\n Wake : 0x00000000 0x00000000\n Calendar: 0x6979ae1a 0x00064953\n\nZone info:\n Zone map: 0xfffffe1000834000 - 0xfffffe3000834000\n . VM : 0xfffffe1000834000 - 0xfffffe14cd500000\n . RO : 0xfffffe14cd500000 - 0xfffffe1666e98000\n . GEN0 : 0xfffffe1666e98000 - 0xfffffe1b33b64000\n . GEN1 : 0xfffffe1b33b64000 - 0xfffffe2000830000\n . GEN2 : 0xfffffe2000830000 - 0xfffffe24cd4fc000\n . GEN3 : 0xfffffe24cd4fc000 - 0xfffffe299a1c8000\n . DATA : 0xfffffe299a1c8000 - 0xfffffe3000834000\n Metadata: 0xfffffe3f4d1ac000 - 0xfffffe3f551ac000\n Bitmaps : 0xfffffe3f551ac000 - 0xfffffe3f5ac94000\n\nCORE 0 recently retired instr at 0xfffffe002569d7a0\nCORE 1 recently retired instr at 0xfffffe002569eea0\nCORE 2 recently retired instr at 0xfffffe002569eea0\nCORE 3 recently retired instr at 0xfffffe002569eea0\nCORE 4 recently retired instr at 0xfffffe002569eea0\nCORE 5 recently retired instr at 0xfffffe002569eea0\nCORE 6 recently retired instr at 0xfffffe002569eea0\nCORE 7 recently retired instr at 0xfffffe002569eea0\nTPIDRx_ELy = {1: 0xfffffe2000c23010 0: 0x0000000000000000 0ro: 0x0000000000000000 }\nCORE 0 PVH locks held: None\nCORE 1 PVH locks held: None\nCORE 2 PVH locks held: None\nCORE 3 PVH locks held: None\nCORE 4 PVH locks held: None\nCORE 5 PVH locks held: None\nCORE 6 PVH locks held: None\nCORE 7 PVH locks held: None\nCORE 0 is the one that panicked. Check the full backtrace for details.\nCORE 1: PC=0xfffffe00279db94c, LR=0xfffffe00260d5d9c, FP=0xfffffe8ffecaf850\nCORE 2: PC=0xfffffe0025be76b0, LR=0xfffffe0025be7628, FP=0xfffffe8fff08f5f0\nCORE 3: PC=0x00000001c7cacd78, LR=0x00000001c7cacd84, FP=0x000000016f485130\nCORE 4: PC=0xfffffe002557f55c, LR=0xfffffe002557f55c, FP=0xfffffe8ffe1dff00\nCORE 5: PC=0xfffffe002557f55c, LR=0xfffffe002557f55c, FP=0xfffffe8fff5eff00\nCORE 6: PC=0xfffffe002557f55c, LR=0xfffffe002557f55c, FP=0xfffffe8ffed8bf00\nCORE 7: PC=0xfffffe002557f55c, LR=0xfffffe002557f55c, FP=0xfffffe8fff11bf00\nCompressor Info: 0% of compressed pages limit (OK) and 0% of segments limit (OK) with 0 swapfiles and OK swap space\nPanicked task 0xfffffe1b33aad678: 0 pages, 470 threads: pid 0: kernel_task\nPanicked thread: 0xfffffe2000c23010, backtrace: 0xfffffe8fff6eb6a0, tid: 265\n\t\t ... Kernel Extensions in backtrace:\n com.apple.driver.AppleT8103PCIeC(1.0)[A595D104-026A-39E5-93AA-4C87CE8C14D2]@0xfffffe0026c619d0->0xfffffe0026c86c97\n dependency: com.apple.driver.AppleARMPlatform(1.0.2)[11A9713E-6739-3A4C-8571-2D8EAA062278]@0xfffffe0025f13ff0->0xfffffe0025f6255f\n dependency: com.apple.driver.AppleEmbeddedPCIE(1)[E71CBCCD-AEB8-3E7B-933D-4FED4241BF13]@0xfffffe002654e0b0->0xfffffe00265684c7\n dependency: com.apple.driver.ApplePIODMA(1)[A419BABC-A7A3-316D-A150-7C2C2D1F6D53]@0xfffffe00269a24b0->0xfffffe00269a6c3b\n dependency: com.apple.driver.IODARTFamily(1)[03997E20-8A3F-3412-A4E8-BD968A75A07D]@0xfffffe00275bcf50->0xfffffe00275d0a3f\n dependency: com.apple.iokit.IOPCIFamily(2.9)[EC78F47B-530B-3F87-854E-0A0A5FD9BBB2]@0xfffffe0027934350->0xfffffe002795f3d3\n dependency: com.apple.iokit.IOReportFamily(47)[843B39D3-146E-3992-B7C7-960148685DC8]@0xfffffe0027963010->0xfffffe0027965ffb\n dependency: com.apple.iokit.IOThunderboltFamily(9.3.3)[B22BC005-BB7B-32A3-99C0-39F3BDBD8E54]@0xfffffe0027a5e3f0->0xfffffe0027b9a1a3\n\nlast started kext at 1915345919: com.sobb.pcie-dma\t1.0.0d1 (addr 0xfffffe00240e47f0, size 9580)\nlast stopped kext at 1774866338: com.sobb.pcie-dma\t1.0.0d1 (addr 0xfffffe00240e47f0, size 9580)\nloaded It seems that the DMA request address initiated by FPGA exceeded 32 bits, which was intercepted by PCIe root port and resulted in a kernel panic.This is also the case on macOS (M2). I have tried the following code interface: IOBufferMemoryDescriptor: a. withCapacity(bufferSize, kIODirectionInOut, true); b. inTaskWithPhysicalMask(kernel_task, kIODirectionInOut, bufferSize, 0x00000000FFFFFFFFULL)。 The physical addresses of the constructed descriptors are all >32 bits; IODMACommand: a. withSpecification(kIODMACommandOutputHost64, 64, 0, IODMACommand::kMapped, 0, 0),gen64IOVMSegments() The allocated IOVM address must be>32 bits, which will generate a kernel panic when used later. b.withSpecification(kIODMACommandOutputHost32, 32, 0, IODMACommand::kMapped, 0, 0),gen32IOVMSegments() The allocation of IOVM failed with error code kIOReturnenMessageTooLarge. So after the above attempts, the analysis shows that the strategy of Dart+PCIe root port on macOS (Apple Silicon) is causing the failure of 64 bit DMA address transfer. I have two questions: a. Does Dart in macOS (Apple Silicon) definitely not allocate <=32-bit IOVM addresses? b. Is there any other way to achieve DMA transfer for FGPA devices on macOS (Apple Silicon)? Thanks!
9
0
437
Feb ’26
Neither macOS 14.7 "Standard" 'AppleUserHIDEventDriver' Matching Driver Nor Custom HIDDriverKit Driver 'IOUserHIDEventService::dispatchDigitizerTouchEvent' API Work for a HID-standard Digitizer Touch Pad Device
I have been working on a multi-platform multi-touch HID-standard digitizer clickpad device. The device uses Bluetooth Low Energy (BLE) as its connectivity transport and advertises HID over GATT. To date, I have the device working successfully on Windows 11 as a multi-touch, gesture-capable click pad with no custom driver or app on Windows. However, I have been having difficulty getting macOS to recognize and react to it as a HID-standard multi-touch click pad digitizer with either the standard Apple HID driver (AppleUserHIDEventDriver) or with a custom-coded driver extension (DEXT) modeled, based on the DTS stylus example and looking at the IOHIDFamily open source driver(s). The trackpad works with full-gesture support on Windows 11 and the descriptors seem to be compliant with the R23 Accessory Guidelines document, §15. With the standard, matching Apple AppleUserHIDEventDriver HID driver, when enumerating using stock-standard HID mouse descriptors, the device works fine on macOS 14.7 "Sonoma" as a relative pointer device with scroll wheel capability (two finger swipe generates a HID scroll report) and a single button. With the standard, matching Apple AppleUserHIDEventDriver HID driver, when enumerating using stock-standard HID digitizer click/touch pad descriptors (those same descriptors used successfully on Windows 11), the device does nothing. No button, no cursor, no gestures, nothing. Looking at ioreg -filtb, all of the key/value pairs for the driver match look correct. Because, even with the Apple open source IOHIDFamily drivers noted above, we could get little visibility into what might be going wrong, I wrote a custom DriverKit/HIDDriverKit driver extension (DEXT) (as noted above, based on the DTS HID stylus example and the open source IOHIDEventDriver. With that custom driver, I can get a single button click from the click pad to work by dispatching button events to dispatchRelativePointerEvent; however, when parsing, processing, and dispatching HID digitizer touch finger (that is, transducer) events via IOUserHIDEventService::dispatchDigitizerTouchEvent, nothing happens. If I log with: % sudo log stream --info --debug --predicate '(subsystem == "com.apple.iohid")' either using the standard AppleUserHIDEventDriver driver or our custom driver, we can see that our input events are tickling the IOHIDNXEventTranslatorSessionFilter HID event filter, so we know HID events are getting from the device into the macOS HID stack. This was further confirmed with the DTS Bluetooth PacketLogger app. Based on these events flowing in and hitting IOHIDNXEventTranslatorSessionFilter, using the standard AppleUserHIDEventDriver driver or our custom driver, clicks or click pad activity will either wake the display or system from sleep and activity will keep the display or system from going to sleep. In short, whether with the stock driver or our custom driver, HID input reports come in over Bluetooth and get processed successfully; however, nothing happens—no pointer movement or gesture recognition. STEPS TO REPRODUCE For the standard AppleUserHIDEventDriver: Pair the device with macOS 14.7 "Sonoma" using the Bluetooth menu. Confirm that it is paired / bonded / connected in the Bluetooth menu. Attempt to click or move one or more fingers on the touchpad surface. Nothing happens. For the our custom driver: Pair the device with macOS 14.7 "Sonoma" using the Bluetooth menu. Confirm that it is paired / bonded / connected in the Bluetooth menu. Attempt to click or move one or more fingers on the touchpad surface. Clicks are correctly registered. With transducer movement, regardless of the number of fingers, nothing happens.
4
0
906
Dec ’25
iOS support for SCSI and NVME commands.
We have a macOS application which interacts with our USB and PCI devices to perform SCSI and NVME commands on them. We use IOUSBHost, IOUSBLib and IOKitLib for USB interface and have created a custom driver to interact with PCI devices. Is there a way we can implement a similar functionality for iOS as well if we connect the cards and readers using OTG?
1
1
269
Mar ’25
Issue Writing to BAR1 After BAR0 is Unavailable
Hello Everyone, I encountered an issue with PCI memory access in DriverKit. In my case, BAR0 is not available, but BAR1 is ready for use. Here’s the log output: !!! ERROR : Failed to get BAR0 info (error: 0xe00002f0). !!! BAR1 - MemoryIndex: 0x00000000, Size: 0x00040000, Type: 0 Issue Description When I initially wrote to BAR0 using memoryIndex = 0, it worked successfully: AME_Address_Write_32(pAMEData, pAMEData->memoryIndex, AME_HOST_INT_MASK_REGISTER, 0x0F); However, I mistakenly forgot to update memoryIndex to 1 for BAR1. Surprisingly, the write operation still succeeded. When I fixed memoryIndex = 1 for BAR1, the write operation no longer had any effect. There was no error, but the expected behavior did not occur. Relevant API (From IOPCIDevice.iig) /*! /*! * @brief Writes a 32-bit value to the PCI device's aperture at a given memory index. * @discussion This method writes a 32-bit register on the device and returns its value. * @param memoryIndex An index into the array of ranges assigned to the device. * @param offset An offset into the device's memory specified by the index. * @param data A 32-bit value to be written in host byte order. */ void MemoryWrite32(uint8_t memoryIndex, uint64_t offset, uint32_t data) LOCALONLY; Log Output: Writes to BAR0 (memoryIndex = 0) AME_Address_Write_32() called memoryIndex: 0, offset: 0x34, data: 0xf Wrote data 0xF to offset 52 AME_Address_Write_32() called memoryIndex: 0, offset: 0xa0, data: 0x1 Wrote data 0x1 to offset 160 AME_Address_Write_32() called memoryIndex: 0, offset: 0x20, data: 0xffffffff Wrote data 0xFFFFFFFF to offset 32 Writes to BAR1 (memoryIndex = 1) – No Response AME_Address_Write_32() called memoryIndex: 1, offset: 0x34, data: 0xf No confirmation log, no visible effect. Questions What should memoryIndex be set to for BAR1? The log shows "BAR1 - MemoryIndex: 0x00000000", but should I be using 1 instead? How can I verify if a write operation to BAR1 is successful? Is there a way to check if the memory region is actually writable? Should I use MemoryRead32() to confirm the written value? Any guidance would be greatly appreciated! Best Regards, Charles
3
1
173
Mar ’25
M1 Air 2020: Failed upgrade from Sequioia 15.3.2 to 15.4, Can't ignore lock validation @t8020dart.c:535
Hi, trying to upgrade from macOS Sequoia 15.3.2 to 15.4 gives this error. Now I can not boot from internal drive of M1 Air 2020, because it restores 15.4, that does not boot. I can only boot from external USB SSD that has macOS 15.3.2. How I can install back 15.3.2 or alternatively newer macOS to internal drive? I only have one Mac, this M1 Air 2020. I have AppleAppleCare+ to 9/18/25. Remaining of error is attached here: Can't ignore lock validation @t8020dart.c:535 panic(cpu 2 caller 0x0): t8020dart 0xfffffdf053908000 (dart-dispext0): Can't ignore lock validation @t8020dart.c:535 Debugger message: panic Memory ID: 0x6 OS release type: Not set yet OS version: Not set yet Kernel version: Darwin Kernel Version 24.4.0: Wed Mar 19 21:12:54 PDT 2025; root:xnu-11417.101.15~1/RELEASE_ARM64_T8103 Fileset Kernelcache UUID: 2BBA525B95E0E6B962ECC44FC093AB57 Kernel UUID: 4E6CBD31-CD1E-3939-8A63-211A206AFA66 Boot session UUID: 3A34167D-2534-402F-9679-2CAD45F67CDA iBoot version: iBoot-11881.101.1 iBoot Stage 2 version: iBoot-11881.101.1 secure boot?: YES
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1
1.3k
Apr ’25
limitations of UserSendCDB in SCSIPeripheralsDriverKit?
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; }
3
0
351
Sep ’25
CreateMemoryDescriptorFromClient can't write data to user?
We've developed a PCIDriverKit driver for the capture card on macOS and have identified an issue: CreateMemoryDescriptorFromClient can only read data from the user space to the driver, but cannot write data back to the user. typedef struct _MWCAP_EDID_DATA { uint64_t size; uint64_t uaddr; } MWCAP_EDID_DATA; // App size_t xxx::GetEdid(void *buff, size_t size) { MWCAP_EDID_DATA edid; edid.size = size; edid.uaddr = (uint64_t)buff; kr = IOConnectCallStructMethod( connect, kUserGetEdid, &edid, sizeof(MWCAP_EDID_DATA), NULL, NULL ); // kr is 0. But However, the data in the buffer remains unchanged; // it does not reflect the EDID copied from the DEXT. return size; } // Driver MWCAP_EDID_DATA *edid = (MWCAP_EDID_DATA *)input; IOMemoryDescriptor *user_buf_mem = NULL; IOAddressSegment segment; segment.address = edid->uaddr; segment.length = edid->size; // We have verified that the values in edid->uaddr and edid->size are consistent with what was set by the application. ret = CreateMemoryDescriptorFromClient(kIOMemoryDirectionOutIn, 1, &segment, &user_buf_mem); if (ret != kIOReturnSuccess) { os_log(OS_LOG_DEFAULT, "Failed to create memdesc with error: 0x%08x", ret); break; } IOMemoryMap* user_buf_map = nullptr; ret = user_buf_mem->CreateMapping(0, 0, 0, 0, 0, &user_buf_map); if (ret != kIOReturnSuccess) { os_log(OS_LOG_DEFAULT, "Failed to create mapping with error: 0x%08x", ret); OSSafeReleaseNULL(user_buf_mem); break; } // ... fill the user_buf_map with edid data ... // For example: // memcpy(user_buf_map->GetAddress(), source_edid_data, edid->size); // At this point we have also verified the data in user_buf_map->GetAddress(), which matches our expectations. OSSafeReleaseNULL(user_buf_map); OSSafeReleaseNULL(user_buf_mem); Please help take a look, thank you!
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0
212
Oct ’25
How to sending capability requests.
I want to create a DriverKit driver and send vendor-specific commands to the storage device. Since UserClient is required to access the DriverKit driver from the app, I am attempting to implement it by referring to the following sample code. [Communicating between a DriverKit extension and a client app] I want to add com.apple.developer.driverkit.allow-any-userclient-access to the driver's Entitlements, submit a Capability Request on the developer site, and create a Provisioning Profile. However, I don't know how to enable com.apple.developer.driverkit.allow-any-userclient-access. I am entering the following information in the “Request a System Extension or DriverKit Entitlement” form. Which entitlement are you applying for? : DriverKit Entitlement Which DriverKit entitlements do you need? : UserClient Access UserClient Bundle IDs : [Bundle ID of MyDriver] Describe your apps and how they’ll use these entitlements. : testing sample code However, even if this request is accepted, I believe only MyDriver will be permitted. How can I grant access to all UserClients?
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152
Nov ’25
Driver Activation failure error code 9. Maybe Entitlements? Please help
This is my first driver and I have had the devil of a time trying to find any information to help me with this. I beg help with this, since I cannot find any tutorials that will get me over this problem. I am attempting to write a bridging driver for an older UPS that only communicates via RPC-over-USB rather than the HID Power Device class the OS requires. I have written the basic framework for the driver (details below) and am calling OSSystemExtensionRequest.submitRequest with a request object created by OSSystemExtensionRequest.activationRequest, but the didFailWithError callback is called with OSSystemExtensionErrorDomain of a value of 9, which appears to be a general failure to activate the driver. I can find no other information on how to address this issue, but I presume the issue is one of entitlements in either the entitlements file or Info.plist. I will have more code-based details below. For testing context, I am testing this on a 2021 iMac (M1) running Sequoia 15.7, and this iMac is on MDM, specifically Jamf. I have disabled SIP and set systemextensionsctl developer on, per the instructions here, and I have compiled and am attempting to debug the app using xcode 26.2. The driver itself targets DriverKit 25, as 26 does not appear to be available in xcode despite hints on google that it's out. For the software, I have a two-target structure in my xcode project, the main Manager app, which is a swift-ui app that both handles installation/activation of the driver and (if that finally manages to work) handles communication from the driver via its UserClient, and the driver which compiles as a dext. Both apps compile and use automated signing attached to our Apple Development team. I won't delve into the Manager app much, as it runs even though activation fails, except to include its entitlements file in case it proves relevant <dict> <key>com.apple.developer.driverkit.communicates-with-drivers</key> <true/> <key>com.apple.developer.system-extension.install</key> <true/> <key>com.apple.security.app-sandbox</key> <true/> <key>com.apple.security.files.user-selected.read-only</key> <true/> </dict> and the relevant activation code: func request(_ request: OSSystemExtensionRequest, didFailWithError error: any Error) { // handling the error, which is always code value 9 } func activateDriver() { let request = OSSystemExtensionRequest.activationRequest(forExtensionWithIdentifier: "com.mycompany.driver.bundle.identifier", queue: .main) request.delegate = self OSSystemExtensionManager.shared.submitRequest(request) //... } And finally the Manager app has the following capabilities requested for its matching identifier in our Apple Developer Account: DriverKit Communicates with Drivers System Extension On the Driver side, I have two major pieces, the main driver class MyDriver, and UserClient class, StatusUserClient. MyDriver derives from IDriverKit/IOService.iig but (in case this is somehow important) does not have the same name as the project/target name MyBatteryDriver. StatusUserClient derives from DriverKit/IOUserClient.iig. I have os_log(OS_LOG_DEFAULT, "trace messages") code in every method of both classes, including the initializers and Start implementations, and the log entries never seem to show up in Console, so I presume that means the OS never tried to load the driver. Unless I'm looking in the wrong place? Because I don't think the driver code is the current issue, I won't go into it unless it becomes necessary. As I mentioned above, I think this is a code signing / entitlements issue, but I don't know how to resolve it. In our Apple Developer account, the Driver's matching identifier has the following capabilities requested: DriverKit (development) DriverKit Allow Any UserClient (development) DriverKit Family HID Device (development) -- NOTE: this is planned for future use, but not yet implemented by my driver code. Could that be part of the problem? DriverKit Transport HID (development) DriverKit USB Transport (development) DriverKit USB Transport - VendorID -- submitted, no response from Apple yet HID Virtual Device -- submitted, no response from Apple. yet. This is vestigial from an early plan to build the bridge via shared memory funneling to a virtual HID device. I think I've found a way to do it with one Service, but... not sure yet. Still, that's a problem for tomorrow. Apparently I've gone over the 7000 character maximum so I will add my entitlements and info.plist contents in a reply.
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380
2w
DriverKit USB: CreateInterfaceIterator returns empty on iPadOS for vendor-class device
I'm developing a DriverKit USB driver for iPadOS that needs to communicate with a vendor-class USB device (bInterfaceClass = 0xFF) as I need to communicate with a USB device using a custom protocol over IOUSBHostPipe for bulk transfers. Current Configuration: Info.plist: IOProviderClass = IOUSBHostDevice Device: bDeviceClass = 0, bInterfaceClass = 0xFF (vendor-specific) What Works: Driver matches and loads successfully Start_Impl() executes device->Open() succeeds device->SetConfiguration() succeeds The Problem: uintptr_t iterRef = 0; kern_return_t ret = device->CreateInterfaceIterator(&iterRef); Result: ret = kIOReturnSuccess (0x0), but iterRef = 0 (empty iterator) What I've Tried: Matching IOUSBHostInterface directly - Driver is loaded, but extension never executed Current approach (IOUSBHostDevice) - Driver extension loads and starts, but CreateInterfaceIterator returns empty Question: Does iPadOS allow third-party DriverKit extensions to access vendor-class (0xFF) USB devices? That is, iPadOS, is there a way for a third-party DriverKit extension to access IOUSBHostInterface objects for vendor-class (0xFF) USB devices?
1
1
179
Jan ’26
DriverKit driver doesn't appear in Settings when installed with iPad app
I'm working on a DriverKit driver. I have it running on macOS, including a very simple client app written in SwiftUI. Everything is working fine there. I've added iPadOS as a destination for the app as demonstrated in the WWDC video on DriverKit for iPadOS. The app builds and runs on my iPad, as expected (after a little work to conditionalize out my use of SystemExtensions.framework for installation on macOS). However, after installing and running the app on an iPad, the driver does not show up in Settings->General, nor in the app-specific settings pane triggered by the inclusion of a settings bundle in the app. I've confirmed that the dext is indeed being included in the app bundle when built for iPadOS (in MyApp.app/SystemExtensions/com.me.MyApp.MyDriver.dext). I also can see in the build log that there's a validation step for the dext, and that seems to be succeeding. I don't know why the app isn't being discovered -- or in any case surfaced to the user -- when the app is installed on the iPad. Has anyone faced this problem and solved it? Are there ways to troubleshoot installation/discovery of an embedded DriverKit extensions on iOS? Unlike on macOS, I don't really see any relevant console messages.
6
2
2.1k
Apr ’25
iPAD: achieve UserClient's privileges in background to have robust IOServiceAddMatchingNotification(...) as if ~[Background modes][Enable external communications].
1) The circumstances: iPADOS~>18, USB still-imaging-gadget, 1-3 gadgets might connect simultaneously via USB-hub, proprietary DExt, UserClient App in developers' iPADs or in TestFlight. = 1 variation A) UserClientApp has attribute [Background modes][Enable external communications]. = 1 variation B) "active USB-hub" vs "passive". = 1 variation C) "ConsoleApp logs iPAD" vs "ConsoleApp is not started". = 1 the term "zombie" below assume issue: == after plug-in ConsoleApp logs "IOUsbUserInterface::init", "::start"; == UserClient never receives respective callback from IOServiceAddMatchingNotification == further IOKit APIs "teardown", "restart" and "re-enumeration of connected gadgets" doesn't reveal the zombie (while it sees another simultaneous gadget); == unplug of the gadget logs "IOUsbUserInterface::stop". =2) The situation when UserClient is in foreground: ~ everything is fine. Note in MAC OS everything (same DExt and UserClient-code) works fine in background and in foreground. =3) The situation when UserClient is in background (beneath ~"Files" or "Safari"): =3A) "1A=true" phys plugin causes zombie in ~1/20 cases (satisfactory) =3B) "1A=false" phys plugin causes zombie in ~1/4 cases (non-satisfactory) =3C) "1 variation B" and "1 variation C" reduce zombies by ~>30%. =3D) ConsoleApp logs with filter "IOAccessory" (~about USB-energy) always look similar by my eyes. =4) From Apple-store: "The app declares support for external-accessory in the UIBackgroundModes"..."The external accessory background mode is intended for apps that communicate with hardware accessories through the External Accessory framework."..."Additionally, the app must be authorized by MFi," =5) My wish/ask: =5 option A) A clue to resolve the "zombie-plugin-issue in background" in a technical manner. = E.g. find a straightforward solution that ~elevates UserClient's "privileges" in background like [Enable external communication]... E.g. what ConsoleApp-logs to add/watch to reveal my potential bugs in DExt or in UserClient? =5 option B) A way to pursue Apple-store to accept (without MFI) an UserClientApp with [Enable external communication].
5
0
370
Oct ’25
Cancel 'Share age range in app'
Hello I'm testing an 'age range sharing' feature using the AgeRangeService API in an app we service. I approved 'Age Sharing' during testing. (For your information, my account is an adult account.) For repeat testing, I would like to delete the our app from 'Apps that requested user age information' or cancel the sharing status. However, there doesn't seem to be such a feature. Is there a way I can't find, or is this a feature that Apple doesn't offer?
1
0
500
Dec ’25
Problem with DriverKitUserClientSample
First time working with DEXT, so I'm trying to make "Communicating between a DriverKit extension and a client app" sample project to work and I'm having trouble. I'm following the steps for "Automatically manage signing". It seems that the step “Sign to Run Locally” is wrong now, so I let it to Apple Developer. Now I have a Provisioning Profile error that says it doesn't include the com.apple.developer.driverkit.allow-any-userclient-access entitlement. If I go to Certificates, Identifiers and Profiles for this AppID and go to Capability Requests and select DriverKit Allow Any UserClient Access, this bring me to a page where I select DriverKit Entitlement but Any UserClient Access is not a choice. I tried asking for UserClient Access but the request has been denied saying that the engineering team does not think these entitlements are necessary for testing locally. So I removed com.apple.developer.driverkit.allow-any-userclient-access from NullDriver.entitlements. I can now install the DEXT but when I try "Communicate with Dext" button, I received the error: Failed opening connection to dext with error: 0xe00002e2. Looking in the console, I see this error message: DK: NullDriverUserClient-0x10000ad6a:UC failed userclient-access check, needed bundle ID com.example.apple-samplecode.dext-to-user-client-2-TEST.driver I tried many things, but I can't seem to be able to pass through the check to allow the application to communicate with the dext. What am I missing? Note that I'm focusing only on macOS, not iOS. Thanks.
Replies
7
Boosts
0
Views
243
Activity
Nov ’25
System Panic with IOUserSCSIParallelInterfaceController during Dispatch Queue Configuration
Hello everyone, We are in the process of migrating a high-performance storage KEXT to DriverKit. During our initial validation phase, we noticed a performance gap between the DEXT and the KEXT, which prompted us to try and optimize our I/O handling process. Background and Motivation: Our test hardware is a RAID 0 array of two HDDs. According to AJA System Test, our legacy KEXT achieves a write speed of about 645 MB/s on this hardware, whereas the new DEXT reaches about 565 MB/s. We suspect the primary reason for this performance gap might be that the DEXT, by default, uses a serial work-loop to submit I/O commands, which fails to fully leverage the parallelism of the hardware array. Therefore, to eliminate this bottleneck and improve performance, we configured a dedicated parallel dispatch queue (MyParallelIOQueue) for the UserProcessParallelTask method. However, during our implementation attempt, we encountered a critical issue that caused a system-wide crash. The Operation Causing the Panic: We configured MyParallelIOQueue using the following combination of methods: In the .iig file: We appended the QUEUENAME(MyParallelIOQueue) macro after the override keyword of the UserProcessParallelTask method declaration. In the .cpp file: We manually created a queue with the same name by calling the IODispatchQueue::Create() function within our UserInitializeController method. The Result: This results in a macOS kernel panic during the DEXT loading process, forcing the user to perform a hard reboot. After the reboot, checking with the systemextensionsctl list command reveals the DEXT's status as [activated waiting for user], which indicates that it encountered an unrecoverable, fatal error during its initialization. Key Code Snippets to Reproduce the Panic: In .iig file - this was our exact implementation: class DRV_MAIN_CLASS_NAME: public IOUserSCSIParallelInterfaceController { public: virtual kern_return_t UserProcessParallelTask(...) override QUEUENAME(MyParallelIOQueue); }; In .h file: struct DRV_MAIN_CLASS_NAME_IVars { // ... IODispatchQueue* MyParallelIOQueue; }; In UserInitializeController implementation: kern_return_t IMPL(DRV_MAIN_CLASS_NAME, UserInitializeController) { // ... // We also included code to manually create the queue. kern_return_t ret = IODispatchQueue::Create("MyParallelIOQueue", kIODispatchQueueReentrant, 0, &ivars->MyParallelIOQueue); if (ret != kIOReturnSuccess) { // ... error handling ... } // ... return kIOReturnSuccess; } Our Question: What is the officially recommended and most stable method for configuring UserProcessParallelTask_Impl() to use a parallel I/O queue? Clarifying this is crucial for all developers pursuing high-performance storage solutions with DriverKit. Any explanation or guidance would be greatly appreciated. Best Regards, Charles
Replies
21
Boosts
0
Views
863
Activity
Feb ’26
INQUIRY command is ILLEGAL REQUEST
I am developing a DriverKit driver with the goal of sending vendor-specific commands to a USB storage device. I have successfully created the DriverKit driver, and when I connect the USB storage device, it appears correctly in IORegistryExplorer. My driver class inherits from IOUserSCSIPeripheralDeviceType00 in the SCSIPeripheralsDriverKit framework. I also created a UserClient class that inherits from IOUserClient, and from its ExternalMethod I tried sending an INQUIRY command as a basic test to confirm that command transmission works. However, the device returns an ILLEGAL REQUEST (Sense Key 0x5 / ASC 0x20). Could someone advise what I might be doing wrong? Below are the logs output from the driver: 2025-11-14 21:00:43.573730+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] Driver - NewUserClient() - Finished. 2025-11-14 21:00:43.573733+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - Start() 2025-11-14 21:00:43.573807+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - Start() - Finished. 2025-11-14 21:00:43.574249+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - ExternalMethod() called 2025-11-14 21:00:43.574258+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - ----- SCSICmdINQUIRY ----- 2025-11-14 21:00:43.574268+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - command.fRequestedByteCountOfTransfer = 512 2025-11-14 21:00:43.575980+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB fCompletionStatus = 0x0 2025-11-14 21:00:43.575988+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB fServiceResponse = 0x2 2025-11-14 21:00:43.575990+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB fSenseDataValid = 0x1 2025-11-14 21:00:43.575992+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB VALID_RESPONSE_CODE = 0x70 2025-11-14 21:00:43.575994+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB SENSE_KEY = 0x5 2025-11-14 21:00:43.575996+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB ADDITIONAL_SENSE_CODE = 0x20 2025-11-14 21:00:43.575998+0900 0x26e9 Default 0x0 0 0 kernel: (SampleDriverKitApp.SampleDriverKitDriver.dext) [DEBUG] UserClient - SCSICmdINQUIRY() UserSendCDB ADDITIONAL_SENSE_CODE_QUALIFIER = 0x0 Here is the UserClient class: class SampleDriverKitUserClient: public IOUserClient { public: virtual bool init(void) override; virtual kern_return_t Start(IOService* provider) override; virtual kern_return_t Stop(IOService* provider) override; virtual void free(void) override; virtual kern_return_t ExternalMethod( uint64_t selector, IOUserClientMethodArguments* arguments, const IOUserClientMethodDispatch* dispatch, OSObject* target, void* reference) override; void SCSICmdINQUIRY(SampleDriverKitDriver *driver) LOCALONLY; }; Here is the part that sends the INQUIRY command: void SampleDriverKitUserClient::SCSICmdINQUIRY(SampleDriverKitDriver *driver) { kern_return_t kr = KERN_SUCCESS; SCSIType00OutParameters command = {}; UInt8 dataBuffer[512] = {0}; SCSI_Sense_Data senseData = {0}; Log("----- SCSICmdINQUIRY -----"); SetCommandCDB(&command.fCommandDescriptorBlock, 0x12, 0x00, 0x00, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00); command.fLogicalUnitNumber = 0; command.fTimeoutDuration = 10000; // milliseconds command.fRequestedByteCountOfTransfer = sizeof(dataBuffer); Log("command.fRequestedByteCountOfTransfer = %lld", command.fRequestedByteCountOfTransfer); command.fBufferDirection = kIOMemoryDirectionIn; command.fDataTransferDirection = kSCSIDataTransfer_FromTargetToInitiator; command.fDataBufferAddr = reinterpret_cast<uint64_t>(dataBuffer); command.fSenseBufferAddr = reinterpret_cast<uint64_t>(&senseData); command.fSenseLengthRequested = sizeof(senseData); if( driver ) { SCSIType00InParameters response = {}; kr = driver->UserSendCDB(command, &response); if( kr != KERN_SUCCESS ) { Log("SCSICmdINQUIRY() UserSendCDB failed (0x%x)", kr); return; } Log("SCSICmdINQUIRY() UserSendCDB fCompletionStatus = 0x%x", response.fCompletionStatus); Log("SCSICmdINQUIRY() UserSendCDB fServiceResponse = 0x%x", response.fServiceResponse); Log("SCSICmdINQUIRY() UserSendCDB fSenseDataValid = 0x%x", response.fSenseDataValid); Log("SCSICmdINQUIRY() UserSendCDB VALID_RESPONSE_CODE = 0x%x", senseData.VALID_RESPONSE_CODE); Log("SCSICmdINQUIRY() UserSendCDB SENSE_KEY = 0x%x", senseData.SENSE_KEY); Log("SCSICmdINQUIRY() UserSendCDB ADDITIONAL_SENSE_CODE = 0x%x", senseData.ADDITIONAL_SENSE_CODE); Log("SCSICmdINQUIRY() UserSendCDB ADDITIONAL_SENSE_CODE_QUALIFIER = 0x%x", senseData.ADDITIONAL_SENSE_CODE_QUALIFIER); if( response.fServiceResponse == kSCSIServiceResponse_TASK_COMPLETE ) { Log("SCSICmdINQUIRY() UserSendCDB complete success!!"); } for( int i=0; i < 5; i++ ) { Log("data [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x [%04d]=0x%x", i*8+0, dataBuffer[i*8+0], i*8+1, dataBuffer[i*8+1], i*8+2, dataBuffer[i*8+2], i*8+3, dataBuffer[i*8+3], i*8+4, dataBuffer[i*8+4], i*8+5, dataBuffer[i*8+5], i*8+6, dataBuffer[i*8+6], i*8+7, dataBuffer[i*8+7] ); } char vendorID[9] = {0}; memcpy(vendorID, &dataBuffer[8], 8); Log("vendorID = %s",vendorID); char productID[17] = {0}; memcpy(productID, &dataBuffer[16], 16); Log("productID = %s",productID); } } My environment is: MacBook Pro (M2), macOS 15.6 If anyone has insight into what causes the ILLEGAL REQUEST, or what I am missing when using IOUserSCSIPeripheralDeviceType00 and UserSendCDB, I would greatly appreciate your help. Thank you.
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Activity
Nov ’25
The total DMA size in DriverKit cannot exceed 2G?
We are developing a DriverKit driver on Apple M1. We use the following code to prepare DMA buffer: IODMACommandSpecification dmaSpecification; bzero(&dmaSpecification, sizeof(dmaSpecification)); dmaSpecification.options = kIODMACommandSpecificationNoOptions; dmaSpecification.maxAddressBits = p_dma_mgr->maxAddressBits; kret = IODMACommand::Create(p_dma_mgr->device, kIODMACommandCreateNoOptions, &dmaSpecification, &impl->dma_cmd ); if (kret != kIOReturnSuccess) { os_log(OS_LOG_DEFAULT, "Error: IODMACommand::Create failed! ret=0x%x\n", kret); impl->user_mem.reset(); IOFree(impl, sizeof(*impl)); return ret; } uint64_t flags = 0; uint32_t segmentsCount = 32; IOAddressSegment segments[32]; kret = impl->dma_cmd->PrepareForDMA(kIODMACommandPrepareForDMANoOptions, impl->user_mem.get(), 0, 0, // 0 for entire memory &flags, &segmentsCount, segments ); if (kret != kIOReturnSuccess) { OSSafeReleaseNULL(impl->dma_cmd); impl->user_mem.reset(); IOFree(impl, sizeof(*impl)); os_log(OS_LOG_DEFAULT, "Error: PrepareForDMA failed! ret=0x%x\n", kret); return kret; } I allocated several 8K BGRA video frames, each with a size of 141557760 bytes, and prepared the DMA according to the method mentioned above. The process was successful when the number of frames was 15 or fewer. However, issues arose when allocating 16 frames: Error: PrepareForDMA failed! ret=0xe00002bd By calculating, I found that the total size of 16 video frames exceeds 2GB. Is there such a limitation in DriverKit that the total DMA size cannot exceed 2GB? Are there any methods that would allow me to bypass this restriction so I can use more video frame buffers?
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Activity
Dec ’25
MacOS(Apple Silicon) IOKit driver for FPGA DMA transmission, kernel panic.
MacOS(Apple Silicon) IOKit driver for FPGA DMA transmission, kernel panic. Hardware and software configuration: MAC mini M1 2020 16GB, macOS Ventura 13.0 or 13.7.8 FPGA device capability: 64-bit Complete description: We've developed a DMA driver for PCIe devices (FPGA) based on IOKit. The driver can start normally through kextload, and the bar mapping, DMA registers, etc. are all correct. I am testing DMA data transmission, but a kernel panic has occurred. The specific content of the panic is as follows: {"bug_type":"210","timestamp":"2026-01-28 14:35:30.00 +0800","os_version":"macOS 13.0 (22A380)","roots_installed":0,"incident_id":"61C9B820-8D1B-4E75-A4EB-10DC2558FA75"} { "build" : "macOS 13.0 (22A380)", "product" : "Macmini9,1", "socId" : "0x00008103", "kernel" : "Darwin Kernel Version 22.1.0: Sun Oct 9 20:14:30 PDT 2022; root:xnu-8792.41.9~2/RELEASE_ARM64_T8103", "incident" : "61C9B820-8D1B-4E75-A4EB-10DC2558FA75", "crashReporterKey" : "6435F6BD-4138-412A-5142-83DD7E5B4F61", "date" : "2026-01-28 14:35:30.16 +0800", "panicString" : "panic(cpu 0 caller 0xfffffe0026c78c2c): "apciec[pcic0-bridge]::handleInterrupt: Request address is greater than 32 bits linksts=0x99000001 pcielint=0x02220060 linkcdmsts=0x00000000 (ltssm 0x11=L0)\n" @AppleT8103PCIeCPort.cpp:1301\nDebugger message: panic\nMemory ID: 0x6\nOS release type: User\nOS version: 22A380\nKernel version: Darwin Kernel Version 22.1.0: Sun Oct 9 20:14:30 PDT 2022; root:xnu-8792.41.9~2/RELEASE_ARM64_T8103\nFileset Kernelcache UUID: C222B4132B9708E5E0E2E8B8C5896410\nKernel UUID: 0BFE6A5D-118B-3889-AE2B-D34A0117A062\nBoot session UUID: 61C9B820-8D1B-4E75-A4EB-10DC2558FA75\niBoot version: iBoot-8419.41.10\nsecure boot?: YES\nroots installed: 0\nPaniclog version: 14\nKernelCache slide: 0x000000001d1b4000\nKernelCache base: 0xfffffe00241b8000\nKernel slide: 0x000000001e3f8000\nKernel text base: 0xfffffe00253fc000\nKernel text exec slide: 0x000000001e4e0000\nKernel text exec base: 0xfffffe00254e4000\nmach_absolute_time: 0x907c3082\nEpoch Time: sec usec\n Boot : 0x6979adbb 0x00023a6a\n Sleep : 0x00000000 0x00000000\n Wake : 0x00000000 0x00000000\n Calendar: 0x6979ae1a 0x00064953\n\nZone info:\n Zone map: 0xfffffe1000834000 - 0xfffffe3000834000\n . VM : 0xfffffe1000834000 - 0xfffffe14cd500000\n . RO : 0xfffffe14cd500000 - 0xfffffe1666e98000\n . GEN0 : 0xfffffe1666e98000 - 0xfffffe1b33b64000\n . GEN1 : 0xfffffe1b33b64000 - 0xfffffe2000830000\n . GEN2 : 0xfffffe2000830000 - 0xfffffe24cd4fc000\n . GEN3 : 0xfffffe24cd4fc000 - 0xfffffe299a1c8000\n . DATA : 0xfffffe299a1c8000 - 0xfffffe3000834000\n Metadata: 0xfffffe3f4d1ac000 - 0xfffffe3f551ac000\n Bitmaps : 0xfffffe3f551ac000 - 0xfffffe3f5ac94000\n\nCORE 0 recently retired instr at 0xfffffe002569d7a0\nCORE 1 recently retired instr at 0xfffffe002569eea0\nCORE 2 recently retired instr at 0xfffffe002569eea0\nCORE 3 recently retired instr at 0xfffffe002569eea0\nCORE 4 recently retired instr at 0xfffffe002569eea0\nCORE 5 recently retired instr at 0xfffffe002569eea0\nCORE 6 recently retired instr at 0xfffffe002569eea0\nCORE 7 recently retired instr at 0xfffffe002569eea0\nTPIDRx_ELy = {1: 0xfffffe2000c23010 0: 0x0000000000000000 0ro: 0x0000000000000000 }\nCORE 0 PVH locks held: None\nCORE 1 PVH locks held: None\nCORE 2 PVH locks held: None\nCORE 3 PVH locks held: None\nCORE 4 PVH locks held: None\nCORE 5 PVH locks held: None\nCORE 6 PVH locks held: None\nCORE 7 PVH locks held: None\nCORE 0 is the one that panicked. Check the full backtrace for details.\nCORE 1: PC=0xfffffe00279db94c, LR=0xfffffe00260d5d9c, FP=0xfffffe8ffecaf850\nCORE 2: PC=0xfffffe0025be76b0, LR=0xfffffe0025be7628, FP=0xfffffe8fff08f5f0\nCORE 3: PC=0x00000001c7cacd78, LR=0x00000001c7cacd84, FP=0x000000016f485130\nCORE 4: PC=0xfffffe002557f55c, LR=0xfffffe002557f55c, FP=0xfffffe8ffe1dff00\nCORE 5: PC=0xfffffe002557f55c, LR=0xfffffe002557f55c, FP=0xfffffe8fff5eff00\nCORE 6: PC=0xfffffe002557f55c, LR=0xfffffe002557f55c, FP=0xfffffe8ffed8bf00\nCORE 7: PC=0xfffffe002557f55c, LR=0xfffffe002557f55c, FP=0xfffffe8fff11bf00\nCompressor Info: 0% of compressed pages limit (OK) and 0% of segments limit (OK) with 0 swapfiles and OK swap space\nPanicked task 0xfffffe1b33aad678: 0 pages, 470 threads: pid 0: kernel_task\nPanicked thread: 0xfffffe2000c23010, backtrace: 0xfffffe8fff6eb6a0, tid: 265\n\t\t ... Kernel Extensions in backtrace:\n com.apple.driver.AppleT8103PCIeC(1.0)[A595D104-026A-39E5-93AA-4C87CE8C14D2]@0xfffffe0026c619d0->0xfffffe0026c86c97\n dependency: com.apple.driver.AppleARMPlatform(1.0.2)[11A9713E-6739-3A4C-8571-2D8EAA062278]@0xfffffe0025f13ff0->0xfffffe0025f6255f\n dependency: com.apple.driver.AppleEmbeddedPCIE(1)[E71CBCCD-AEB8-3E7B-933D-4FED4241BF13]@0xfffffe002654e0b0->0xfffffe00265684c7\n dependency: com.apple.driver.ApplePIODMA(1)[A419BABC-A7A3-316D-A150-7C2C2D1F6D53]@0xfffffe00269a24b0->0xfffffe00269a6c3b\n dependency: com.apple.driver.IODARTFamily(1)[03997E20-8A3F-3412-A4E8-BD968A75A07D]@0xfffffe00275bcf50->0xfffffe00275d0a3f\n dependency: com.apple.iokit.IOPCIFamily(2.9)[EC78F47B-530B-3F87-854E-0A0A5FD9BBB2]@0xfffffe0027934350->0xfffffe002795f3d3\n dependency: com.apple.iokit.IOReportFamily(47)[843B39D3-146E-3992-B7C7-960148685DC8]@0xfffffe0027963010->0xfffffe0027965ffb\n dependency: com.apple.iokit.IOThunderboltFamily(9.3.3)[B22BC005-BB7B-32A3-99C0-39F3BDBD8E54]@0xfffffe0027a5e3f0->0xfffffe0027b9a1a3\n\nlast started kext at 1915345919: com.sobb.pcie-dma\t1.0.0d1 (addr 0xfffffe00240e47f0, size 9580)\nlast stopped kext at 1774866338: com.sobb.pcie-dma\t1.0.0d1 (addr 0xfffffe00240e47f0, size 9580)\nloaded It seems that the DMA request address initiated by FPGA exceeded 32 bits, which was intercepted by PCIe root port and resulted in a kernel panic.This is also the case on macOS (M2). I have tried the following code interface: IOBufferMemoryDescriptor: a. withCapacity(bufferSize, kIODirectionInOut, true); b. inTaskWithPhysicalMask(kernel_task, kIODirectionInOut, bufferSize, 0x00000000FFFFFFFFULL)。 The physical addresses of the constructed descriptors are all >32 bits; IODMACommand: a. withSpecification(kIODMACommandOutputHost64, 64, 0, IODMACommand::kMapped, 0, 0),gen64IOVMSegments() The allocated IOVM address must be>32 bits, which will generate a kernel panic when used later. b.withSpecification(kIODMACommandOutputHost32, 32, 0, IODMACommand::kMapped, 0, 0),gen32IOVMSegments() The allocation of IOVM failed with error code kIOReturnenMessageTooLarge. So after the above attempts, the analysis shows that the strategy of Dart+PCIe root port on macOS (Apple Silicon) is causing the failure of 64 bit DMA address transfer. I have two questions: a. Does Dart in macOS (Apple Silicon) definitely not allocate <=32-bit IOVM addresses? b. Is there any other way to achieve DMA transfer for FGPA devices on macOS (Apple Silicon)? Thanks!
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Activity
Feb ’26
Neither macOS 14.7 "Standard" 'AppleUserHIDEventDriver' Matching Driver Nor Custom HIDDriverKit Driver 'IOUserHIDEventService::dispatchDigitizerTouchEvent' API Work for a HID-standard Digitizer Touch Pad Device
I have been working on a multi-platform multi-touch HID-standard digitizer clickpad device. The device uses Bluetooth Low Energy (BLE) as its connectivity transport and advertises HID over GATT. To date, I have the device working successfully on Windows 11 as a multi-touch, gesture-capable click pad with no custom driver or app on Windows. However, I have been having difficulty getting macOS to recognize and react to it as a HID-standard multi-touch click pad digitizer with either the standard Apple HID driver (AppleUserHIDEventDriver) or with a custom-coded driver extension (DEXT) modeled, based on the DTS stylus example and looking at the IOHIDFamily open source driver(s). The trackpad works with full-gesture support on Windows 11 and the descriptors seem to be compliant with the R23 Accessory Guidelines document, §15. With the standard, matching Apple AppleUserHIDEventDriver HID driver, when enumerating using stock-standard HID mouse descriptors, the device works fine on macOS 14.7 "Sonoma" as a relative pointer device with scroll wheel capability (two finger swipe generates a HID scroll report) and a single button. With the standard, matching Apple AppleUserHIDEventDriver HID driver, when enumerating using stock-standard HID digitizer click/touch pad descriptors (those same descriptors used successfully on Windows 11), the device does nothing. No button, no cursor, no gestures, nothing. Looking at ioreg -filtb, all of the key/value pairs for the driver match look correct. Because, even with the Apple open source IOHIDFamily drivers noted above, we could get little visibility into what might be going wrong, I wrote a custom DriverKit/HIDDriverKit driver extension (DEXT) (as noted above, based on the DTS HID stylus example and the open source IOHIDEventDriver. With that custom driver, I can get a single button click from the click pad to work by dispatching button events to dispatchRelativePointerEvent; however, when parsing, processing, and dispatching HID digitizer touch finger (that is, transducer) events via IOUserHIDEventService::dispatchDigitizerTouchEvent, nothing happens. If I log with: % sudo log stream --info --debug --predicate '(subsystem == "com.apple.iohid")' either using the standard AppleUserHIDEventDriver driver or our custom driver, we can see that our input events are tickling the IOHIDNXEventTranslatorSessionFilter HID event filter, so we know HID events are getting from the device into the macOS HID stack. This was further confirmed with the DTS Bluetooth PacketLogger app. Based on these events flowing in and hitting IOHIDNXEventTranslatorSessionFilter, using the standard AppleUserHIDEventDriver driver or our custom driver, clicks or click pad activity will either wake the display or system from sleep and activity will keep the display or system from going to sleep. In short, whether with the stock driver or our custom driver, HID input reports come in over Bluetooth and get processed successfully; however, nothing happens—no pointer movement or gesture recognition. STEPS TO REPRODUCE For the standard AppleUserHIDEventDriver: Pair the device with macOS 14.7 "Sonoma" using the Bluetooth menu. Confirm that it is paired / bonded / connected in the Bluetooth menu. Attempt to click or move one or more fingers on the touchpad surface. Nothing happens. For the our custom driver: Pair the device with macOS 14.7 "Sonoma" using the Bluetooth menu. Confirm that it is paired / bonded / connected in the Bluetooth menu. Attempt to click or move one or more fingers on the touchpad surface. Clicks are correctly registered. With transducer movement, regardless of the number of fingers, nothing happens.
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Activity
Dec ’25
iOS support for SCSI and NVME commands.
We have a macOS application which interacts with our USB and PCI devices to perform SCSI and NVME commands on them. We use IOUSBHost, IOUSBLib and IOKitLib for USB interface and have created a custom driver to interact with PCI devices. Is there a way we can implement a similar functionality for iOS as well if we connect the cards and readers using OTG?
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269
Activity
Mar ’25
Issue Writing to BAR1 After BAR0 is Unavailable
Hello Everyone, I encountered an issue with PCI memory access in DriverKit. In my case, BAR0 is not available, but BAR1 is ready for use. Here’s the log output: !!! ERROR : Failed to get BAR0 info (error: 0xe00002f0). !!! BAR1 - MemoryIndex: 0x00000000, Size: 0x00040000, Type: 0 Issue Description When I initially wrote to BAR0 using memoryIndex = 0, it worked successfully: AME_Address_Write_32(pAMEData, pAMEData->memoryIndex, AME_HOST_INT_MASK_REGISTER, 0x0F); However, I mistakenly forgot to update memoryIndex to 1 for BAR1. Surprisingly, the write operation still succeeded. When I fixed memoryIndex = 1 for BAR1, the write operation no longer had any effect. There was no error, but the expected behavior did not occur. Relevant API (From IOPCIDevice.iig) /*! /*! * @brief Writes a 32-bit value to the PCI device's aperture at a given memory index. * @discussion This method writes a 32-bit register on the device and returns its value. * @param memoryIndex An index into the array of ranges assigned to the device. * @param offset An offset into the device's memory specified by the index. * @param data A 32-bit value to be written in host byte order. */ void MemoryWrite32(uint8_t memoryIndex, uint64_t offset, uint32_t data) LOCALONLY; Log Output: Writes to BAR0 (memoryIndex = 0) AME_Address_Write_32() called memoryIndex: 0, offset: 0x34, data: 0xf Wrote data 0xF to offset 52 AME_Address_Write_32() called memoryIndex: 0, offset: 0xa0, data: 0x1 Wrote data 0x1 to offset 160 AME_Address_Write_32() called memoryIndex: 0, offset: 0x20, data: 0xffffffff Wrote data 0xFFFFFFFF to offset 32 Writes to BAR1 (memoryIndex = 1) – No Response AME_Address_Write_32() called memoryIndex: 1, offset: 0x34, data: 0xf No confirmation log, no visible effect. Questions What should memoryIndex be set to for BAR1? The log shows "BAR1 - MemoryIndex: 0x00000000", but should I be using 1 instead? How can I verify if a write operation to BAR1 is successful? Is there a way to check if the memory region is actually writable? Should I use MemoryRead32() to confirm the written value? Any guidance would be greatly appreciated! Best Regards, Charles
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Activity
Mar ’25
M1 Air 2020: Failed upgrade from Sequioia 15.3.2 to 15.4, Can't ignore lock validation @t8020dart.c:535
Hi, trying to upgrade from macOS Sequoia 15.3.2 to 15.4 gives this error. Now I can not boot from internal drive of M1 Air 2020, because it restores 15.4, that does not boot. I can only boot from external USB SSD that has macOS 15.3.2. How I can install back 15.3.2 or alternatively newer macOS to internal drive? I only have one Mac, this M1 Air 2020. I have AppleAppleCare+ to 9/18/25. Remaining of error is attached here: Can't ignore lock validation @t8020dart.c:535 panic(cpu 2 caller 0x0): t8020dart 0xfffffdf053908000 (dart-dispext0): Can't ignore lock validation @t8020dart.c:535 Debugger message: panic Memory ID: 0x6 OS release type: Not set yet OS version: Not set yet Kernel version: Darwin Kernel Version 24.4.0: Wed Mar 19 21:12:54 PDT 2025; root:xnu-11417.101.15~1/RELEASE_ARM64_T8103 Fileset Kernelcache UUID: 2BBA525B95E0E6B962ECC44FC093AB57 Kernel UUID: 4E6CBD31-CD1E-3939-8A63-211A206AFA66 Boot session UUID: 3A34167D-2534-402F-9679-2CAD45F67CDA iBoot version: iBoot-11881.101.1 iBoot Stage 2 version: iBoot-11881.101.1 secure boot?: YES
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Activity
Apr ’25
[iPhone13 Pro Max][iOS 26.3] Camera Freeze after update
My back camera freezes after first frame is displayed on the screen. Issue is present in all the apps that use the back camera. Same issue with front camera, however front camera works with Facetime and WhatsApp but not the native camera app.
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150
Activity
Jul ’25
limitations of UserSendCDB in SCSIPeripheralsDriverKit?
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; }
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Activity
Sep ’25
CreateMemoryDescriptorFromClient can't write data to user?
We've developed a PCIDriverKit driver for the capture card on macOS and have identified an issue: CreateMemoryDescriptorFromClient can only read data from the user space to the driver, but cannot write data back to the user. typedef struct _MWCAP_EDID_DATA { uint64_t size; uint64_t uaddr; } MWCAP_EDID_DATA; // App size_t xxx::GetEdid(void *buff, size_t size) { MWCAP_EDID_DATA edid; edid.size = size; edid.uaddr = (uint64_t)buff; kr = IOConnectCallStructMethod( connect, kUserGetEdid, &edid, sizeof(MWCAP_EDID_DATA), NULL, NULL ); // kr is 0. But However, the data in the buffer remains unchanged; // it does not reflect the EDID copied from the DEXT. return size; } // Driver MWCAP_EDID_DATA *edid = (MWCAP_EDID_DATA *)input; IOMemoryDescriptor *user_buf_mem = NULL; IOAddressSegment segment; segment.address = edid->uaddr; segment.length = edid->size; // We have verified that the values in edid->uaddr and edid->size are consistent with what was set by the application. ret = CreateMemoryDescriptorFromClient(kIOMemoryDirectionOutIn, 1, &segment, &user_buf_mem); if (ret != kIOReturnSuccess) { os_log(OS_LOG_DEFAULT, "Failed to create memdesc with error: 0x%08x", ret); break; } IOMemoryMap* user_buf_map = nullptr; ret = user_buf_mem->CreateMapping(0, 0, 0, 0, 0, &user_buf_map); if (ret != kIOReturnSuccess) { os_log(OS_LOG_DEFAULT, "Failed to create mapping with error: 0x%08x", ret); OSSafeReleaseNULL(user_buf_mem); break; } // ... fill the user_buf_map with edid data ... // For example: // memcpy(user_buf_map->GetAddress(), source_edid_data, edid->size); // At this point we have also verified the data in user_buf_map->GetAddress(), which matches our expectations. OSSafeReleaseNULL(user_buf_map); OSSafeReleaseNULL(user_buf_mem); Please help take a look, thank you!
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212
Activity
Oct ’25
How to sending capability requests.
I want to create a DriverKit driver and send vendor-specific commands to the storage device. Since UserClient is required to access the DriverKit driver from the app, I am attempting to implement it by referring to the following sample code. [Communicating between a DriverKit extension and a client app] I want to add com.apple.developer.driverkit.allow-any-userclient-access to the driver's Entitlements, submit a Capability Request on the developer site, and create a Provisioning Profile. However, I don't know how to enable com.apple.developer.driverkit.allow-any-userclient-access. I am entering the following information in the “Request a System Extension or DriverKit Entitlement” form. Which entitlement are you applying for? : DriverKit Entitlement Which DriverKit entitlements do you need? : UserClient Access UserClient Bundle IDs : [Bundle ID of MyDriver] Describe your apps and how they’ll use these entitlements. : testing sample code However, even if this request is accepted, I believe only MyDriver will be permitted. How can I grant access to all UserClients?
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152
Activity
Nov ’25
开发者账户无法注册
在Developer app中现在注册按钮时置灰等,无法点击,我发送的联系邮件也没有得到回应,有什么办法解决吗
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0
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1
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213
Activity
Jan ’26
Driver Activation failure error code 9. Maybe Entitlements? Please help
This is my first driver and I have had the devil of a time trying to find any information to help me with this. I beg help with this, since I cannot find any tutorials that will get me over this problem. I am attempting to write a bridging driver for an older UPS that only communicates via RPC-over-USB rather than the HID Power Device class the OS requires. I have written the basic framework for the driver (details below) and am calling OSSystemExtensionRequest.submitRequest with a request object created by OSSystemExtensionRequest.activationRequest, but the didFailWithError callback is called with OSSystemExtensionErrorDomain of a value of 9, which appears to be a general failure to activate the driver. I can find no other information on how to address this issue, but I presume the issue is one of entitlements in either the entitlements file or Info.plist. I will have more code-based details below. For testing context, I am testing this on a 2021 iMac (M1) running Sequoia 15.7, and this iMac is on MDM, specifically Jamf. I have disabled SIP and set systemextensionsctl developer on, per the instructions here, and I have compiled and am attempting to debug the app using xcode 26.2. The driver itself targets DriverKit 25, as 26 does not appear to be available in xcode despite hints on google that it's out. For the software, I have a two-target structure in my xcode project, the main Manager app, which is a swift-ui app that both handles installation/activation of the driver and (if that finally manages to work) handles communication from the driver via its UserClient, and the driver which compiles as a dext. Both apps compile and use automated signing attached to our Apple Development team. I won't delve into the Manager app much, as it runs even though activation fails, except to include its entitlements file in case it proves relevant <dict> <key>com.apple.developer.driverkit.communicates-with-drivers</key> <true/> <key>com.apple.developer.system-extension.install</key> <true/> <key>com.apple.security.app-sandbox</key> <true/> <key>com.apple.security.files.user-selected.read-only</key> <true/> </dict> and the relevant activation code: func request(_ request: OSSystemExtensionRequest, didFailWithError error: any Error) { // handling the error, which is always code value 9 } func activateDriver() { let request = OSSystemExtensionRequest.activationRequest(forExtensionWithIdentifier: "com.mycompany.driver.bundle.identifier", queue: .main) request.delegate = self OSSystemExtensionManager.shared.submitRequest(request) //... } And finally the Manager app has the following capabilities requested for its matching identifier in our Apple Developer Account: DriverKit Communicates with Drivers System Extension On the Driver side, I have two major pieces, the main driver class MyDriver, and UserClient class, StatusUserClient. MyDriver derives from IDriverKit/IOService.iig but (in case this is somehow important) does not have the same name as the project/target name MyBatteryDriver. StatusUserClient derives from DriverKit/IOUserClient.iig. I have os_log(OS_LOG_DEFAULT, "trace messages") code in every method of both classes, including the initializers and Start implementations, and the log entries never seem to show up in Console, so I presume that means the OS never tried to load the driver. Unless I'm looking in the wrong place? Because I don't think the driver code is the current issue, I won't go into it unless it becomes necessary. As I mentioned above, I think this is a code signing / entitlements issue, but I don't know how to resolve it. In our Apple Developer account, the Driver's matching identifier has the following capabilities requested: DriverKit (development) DriverKit Allow Any UserClient (development) DriverKit Family HID Device (development) -- NOTE: this is planned for future use, but not yet implemented by my driver code. Could that be part of the problem? DriverKit Transport HID (development) DriverKit USB Transport (development) DriverKit USB Transport - VendorID -- submitted, no response from Apple yet HID Virtual Device -- submitted, no response from Apple. yet. This is vestigial from an early plan to build the bridge via shared memory funneling to a virtual HID device. I think I've found a way to do it with one Service, but... not sure yet. Still, that's a problem for tomorrow. Apparently I've gone over the 7000 character maximum so I will add my entitlements and info.plist contents in a reply.
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10
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380
Activity
2w
DriverKit USB: CreateInterfaceIterator returns empty on iPadOS for vendor-class device
I'm developing a DriverKit USB driver for iPadOS that needs to communicate with a vendor-class USB device (bInterfaceClass = 0xFF) as I need to communicate with a USB device using a custom protocol over IOUSBHostPipe for bulk transfers. Current Configuration: Info.plist: IOProviderClass = IOUSBHostDevice Device: bDeviceClass = 0, bInterfaceClass = 0xFF (vendor-specific) What Works: Driver matches and loads successfully Start_Impl() executes device->Open() succeeds device->SetConfiguration() succeeds The Problem: uintptr_t iterRef = 0; kern_return_t ret = device->CreateInterfaceIterator(&iterRef); Result: ret = kIOReturnSuccess (0x0), but iterRef = 0 (empty iterator) What I've Tried: Matching IOUSBHostInterface directly - Driver is loaded, but extension never executed Current approach (IOUSBHostDevice) - Driver extension loads and starts, but CreateInterfaceIterator returns empty Question: Does iPadOS allow third-party DriverKit extensions to access vendor-class (0xFF) USB devices? That is, iPadOS, is there a way for a third-party DriverKit extension to access IOUSBHostInterface objects for vendor-class (0xFF) USB devices?
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1
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179
Activity
Jan ’26
DriverKit vs MFi for iPad custom hardware serial communication?
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?
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2
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57
Activity
2d
DriverKit driver doesn't appear in Settings when installed with iPad app
I'm working on a DriverKit driver. I have it running on macOS, including a very simple client app written in SwiftUI. Everything is working fine there. I've added iPadOS as a destination for the app as demonstrated in the WWDC video on DriverKit for iPadOS. The app builds and runs on my iPad, as expected (after a little work to conditionalize out my use of SystemExtensions.framework for installation on macOS). However, after installing and running the app on an iPad, the driver does not show up in Settings->General, nor in the app-specific settings pane triggered by the inclusion of a settings bundle in the app. I've confirmed that the dext is indeed being included in the app bundle when built for iPadOS (in MyApp.app/SystemExtensions/com.me.MyApp.MyDriver.dext). I also can see in the build log that there's a validation step for the dext, and that seems to be succeeding. I don't know why the app isn't being discovered -- or in any case surfaced to the user -- when the app is installed on the iPad. Has anyone faced this problem and solved it? Are there ways to troubleshoot installation/discovery of an embedded DriverKit extensions on iOS? Unlike on macOS, I don't really see any relevant console messages.
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6
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2.1k
Activity
Apr ’25
iPAD: achieve UserClient's privileges in background to have robust IOServiceAddMatchingNotification(...) as if ~[Background modes][Enable external communications].
1) The circumstances: iPADOS~>18, USB still-imaging-gadget, 1-3 gadgets might connect simultaneously via USB-hub, proprietary DExt, UserClient App in developers' iPADs or in TestFlight. = 1 variation A) UserClientApp has attribute [Background modes][Enable external communications]. = 1 variation B) "active USB-hub" vs "passive". = 1 variation C) "ConsoleApp logs iPAD" vs "ConsoleApp is not started". = 1 the term "zombie" below assume issue: == after plug-in ConsoleApp logs "IOUsbUserInterface::init", "::start"; == UserClient never receives respective callback from IOServiceAddMatchingNotification == further IOKit APIs "teardown", "restart" and "re-enumeration of connected gadgets" doesn't reveal the zombie (while it sees another simultaneous gadget); == unplug of the gadget logs "IOUsbUserInterface::stop". =2) The situation when UserClient is in foreground: ~ everything is fine. Note in MAC OS everything (same DExt and UserClient-code) works fine in background and in foreground. =3) The situation when UserClient is in background (beneath ~"Files" or "Safari"): =3A) "1A=true" phys plugin causes zombie in ~1/20 cases (satisfactory) =3B) "1A=false" phys plugin causes zombie in ~1/4 cases (non-satisfactory) =3C) "1 variation B" and "1 variation C" reduce zombies by ~>30%. =3D) ConsoleApp logs with filter "IOAccessory" (~about USB-energy) always look similar by my eyes. =4) From Apple-store: "The app declares support for external-accessory in the UIBackgroundModes"..."The external accessory background mode is intended for apps that communicate with hardware accessories through the External Accessory framework."..."Additionally, the app must be authorized by MFi," =5) My wish/ask: =5 option A) A clue to resolve the "zombie-plugin-issue in background" in a technical manner. = E.g. find a straightforward solution that ~elevates UserClient's "privileges" in background like [Enable external communication]... E.g. what ConsoleApp-logs to add/watch to reveal my potential bugs in DExt or in UserClient? =5 option B) A way to pursue Apple-store to accept (without MFI) an UserClientApp with [Enable external communication].
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5
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370
Activity
Oct ’25
Cancel 'Share age range in app'
Hello I'm testing an 'age range sharing' feature using the AgeRangeService API in an app we service. I approved 'Age Sharing' during testing. (For your information, my account is an adult account.) For repeat testing, I would like to delete the our app from 'Apps that requested user age information' or cancel the sharing status. However, there doesn't seem to be such a feature. Is there a way I can't find, or is this a feature that Apple doesn't offer?
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1
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500
Activity
Dec ’25