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DriverKit CppUserClient Searching for dext service but Failed opening service with error: 0xe00002c7
Hi Everybody, Follow Communicating between a DriverKit extension and a client app to migrate our kext to dext. The dext might have been loaded successfully by using the command systemextensionsctl list, the dext is loaded and enabled. % sectl list 1 extension(s) --- com.apple.system_extension.driver_extension enabled active teamID bundleID (version) name [state] * * K3TDMD9Y6B com.accusys.scsidriver (1.0/1) com.accusys.scsidriver [activated enabled] We try to use the CppUserClient.cpp to communicate with the dext, but can not get the dext service. The debug message as below: Failed opening service with error: 0xe00002c7. Here is the part of CppUserClient.cpp static const char* dextIdentifier = "com.accusys.scsidriver"; kern_return_t ret = kIOReturnSuccess; io_iterator_t iterator = IO_OBJECT_NULL; io_service_t service = IO_OBJECT_NULL; ret = IOServiceGetMatchingServices(kIOMasterPortDefault, IOServiceMatching("IOUserServer"), &iterator); printf("dextIdentifier = %s\n", dextIdentifier); printf("IOServiceNameMatching return = %d\n", ret); if (ret != kIOReturnSuccess) { printf("Unable to find service for identifier with error: 0x%08x.\n", ret); PrintErrorDetails(ret); } printf("Searching for dext service...\n"); while ((service = IOIteratorNext(iterator)) != IO_OBJECT_NULL) { // Open a connection to this user client as a server to that client, and store the instance in "service" ret = IOServiceOpen(service, mach_task_self_, kIOHIDServerConnectType, &connection); if (ret == kIOReturnSuccess) { printf("\tOpened service.\n"); break; } else { printf("\tFailed opening service with error: 0x%08x.\n", ret); } IOObjectRelease(service); } IOObjectRelease(iterator); if (service == IO_OBJECT_NULL) { printf("Failed to match to device.\n"); return EXIT_FAILURE; } The console output message is dextIdentifier = com.accusys.scsidriver IOServiceNameMatching return = 0 Searching for dext service... Failed opening service with error: 0xe00002c7. Failed opening service with error: 0xe00002c7. Failed opening service with error: 0xe00002c7. Failed opening service with error: 0xe00002c7. Failed to match to device. Here is the log show message fredapp start UserInitializeController pcitest: fredapp pci vendorID: 14d6 deviceID: 626f fredapp nnnnnew configuaration read32 0x10 info: 1 fredapp nnnnnew configuaration read32 0x14 info: 80100004 fredapp new 128 before enable busmaster ReqMSGport_info 0x00000040 : fffff pcitest: fredapp 131 pci ConfigurationRead16 busmaster value 0 pcitest: fredapp 134 Enable BusMaster and IO space done...... locate 139 fredapp MemoryWrite32 function done...... fredapp new 143 after enable busmaster ReqMSGport_info 0x00000040 : 0 fredapp newwww before GetBARInfo memoryIndex1 info is: 5 fredapp GetBARInfo 1 kernel return status is: 0 fredapp GetBARInfo memoryIndex1 info is: 0 fredapp GetBARInfo barSize1 info is: 262144 fredapp GetBARInfo barType1 info is: 0 fredapp GetBARInfo result0 info is: 3758097136 fredapp GetBARInfo memoryIndex0 info is: 0 fredapp GetBARInfo barSize0 info is: 0 fredapp GetBARInfo barType0 info is: 0 pcitest: newwww fredapp againnnn test ReqMSGport info: 8 fredapp Start MPIO_Init_Prepare fredapp end MPIO_Init_Prepare. fredapp call 741 Total_memory_size: 1bb900 fredapp Start MemoryAllocationForAME_Module. fredapp IOBufferMemoryDescriptor create return status info is kIOReturnSuc fredapp IOBufferMemoryDescriptor virtualAddressSegment address info: 0x1 fredapp virtualAddressSegment length info: 0x00080000 fredapp end IOBufferMemoryDescriptor Create. fredapp dmaSpecification maxAddressBits: 0x00000000 fredapp dmaSpecification maxAddressBits: 0x00000027 fredapp IODMACommand create return status info is kIOReturnSuccess fredapp end IODMACommand Create. fredapp PrepareForDMA return status info is kIOReturnSuccess fredapp PrepareForDMA return status info is 0x00000000 fredapp Allocate memory PrepareforDMA return flags info: 0x00000003 fredapp Allocate memory PrepareforDMA return segmentsCount info: 0x00000 fredapp Allocate memory PrepareforDMA return physicalAddressSegment info: fredapp IOBufferMemoryDescriptor virtualAddressSegment address info-2: 0 fredapp verify data success init() - Finished. fredapp start UserGetDMASpecification fredapp end UserGetDMASpecification fredapp start UserMapHBAData fredapp end UserMapHBAData fredapp start UserStartController fredapp interruptType info is 0x00010000 fredapp PCI Dext interrupt final value return status info is 0x00000000 Any suggestions? Best Regards, Charles
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753
Jan ’25
Crash in IOService::Create
I am getting an unexpected crash from IOService::Create() when attempting to create a new user-client. The crash is a nullptr exception in OSCopyInObjects(). The last call from my code was IOService::Create(). As far as I can tell, all the input parameters to Create() are correct, and the Info.plist is has the correct key and class information - indeed, if I corrupt these I get an error status return rather than a crash. Any suggestions as to what could be causing this? I suspect that the problem may be related from a change in the underlying application that is creating the user client. This was modified from a standard app to a daemon, following the advice here: https://developer.apple.com/documentation/xcode/signing-a-daemon-with-a-restricted-entitlement. However, it is the driver that crashes - not the host opening the user client.
1
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494
Jan ’25
howto measure time_interval since physical plugin of a USB-gadget ?
=1) The situation: 1A) I make both a "DExt" and a "SDK" for still-imaging-USB-gadgets and MACOS>=14 ,iPADOS>=17 1B) One of the USB-gadgets needs warm_up after PlugIn (i.e End-User-App must know "now-TheMomentOfPlugIn" with precision ~1sec). =2) The question is how to do "1B" rationally? =3) My speculative guess: in BSD-descendant I expect existence (somewhere) of a "normal file" through "macports etc", which has normal "file creation time". Such a "file creation time" (accessible better via IORegistryEntry... at SDK-level; possibly via IOUSBHostInterface at DExt-level) is cognitive target of mine. =4) Additional constraints: Technically absent. I freely modify code either DExt (descendant of IOUSBHostInterface) or SDK-level (IORegistryEntryGetRegistryEntryID, IORegistryEntry...)
11
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589
Feb ’25
Trouble using IOLog from a dext
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?
5
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587
Feb ’25
No logs from log stream | grep CompanyName
I have USB DriverKit driver. When I use the log command below to get log, there is logs from my driver on my own M-series MacBook where the driver is built using developer account. log stream | grep CompanyName But on other mac like (M-series) Mac Mini, there is no log captured from driver though the driver is communicating with the machine correctly. The only log captured are from MacOS regarding CompanyName driver status/unload/load. The MacOS is Sonoma 14.7.2 and 14.7.3. Please advise on how to get log from driver since writing to files is not allowed in DriverKit. I need logs to troubleshoot on Mac Mini. Thanks.
1
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475
Feb ’25
How to implement mouse (pointing) acceleration function in DriverKit?
Hello every one good day :) My project uses a mouse driver handling all events from the mouse produced by our company. In the past the driver is a kext, which implement acceleration by HIDPointerAccelerationTable, we prepare data in the driver's info.plist, while our app specifies a value to IOHIDSystem with key kIOHIDPointerAccelerationKey, the driver will call copyAccelerationTable() to lookup the HIDPointerAccelerationTable and return a value. In current DriverKit area, the process above is deprecated. Now I don't know to do. I've read some document: https://developer.apple.com/documentation/hiddriverkit/iohidpointereventoptions/kiohidpointereventoptionsnoacceleration?changes=__7_8 https://developer.apple.com/documentation/hiddriverkit/kiohidmouseaccelerationtypekey?changes=__7_8 https://developer.apple.com/documentation/hiddriverkit/kiohidpointeraccelerationkey?changes=__7_8 but no any description in those articles. Please help!
6
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447
Jun ’25
Why UserInitializeTargetForID() not be invoked after UserCreateTargetForID() successfully?
Hello Everyone, I am trying to create a Fake SCSI target based on SCSIControllerDriverKit.framework and inherent from IOUserSCSIParallelInterfaceController, here is the code kern_return_t IMPL(DRV_MAIN_CLASS_NAME, Start) { ... // Programmatically create a null SCSI Target SCSIDeviceIdentifier nullTargetID = 0; // Example target ID, adjust as needed ret = UserCreateTargetForID(nullTargetID, nullptr); if (ret != kIOReturnSuccess) { Log("Failed to create Null SCSI Target for ID %llu", nullTargetID); return ret; } ... } According the document UserCreateTargetForID, after creating a TargetID successfully, the framework will call the UserInitializeTargetForID() The document said: As part of the UserCreateTargetForID call, the kernel calls several APIs like UserInitializeTargetForID which run on the default dispatch queue of the dext. But after UserCreateTargetForID created, why the UserInitializeTargetForID() not be invoked automatically? Here is the part of log show init() - Start init() - End Start() - Start Start() - try 1 times UserCreateTargetForID() - Start Allocating resources for Target ID 0 UserCreateTargetForID() - End Start() - Finished. UserInitializeController() - Start - PCI vendorID: 0x14d6, deviceID: 0x626f. - BAR0: 0x1, BAR1: 0x200004. - GetBARInfo() - BAR1 - MemoryIndex: 0, Size: 262144, Type: 0. UserInitializeController() - End UserStartController() - Start - msiInterruptIndex : 0x00000000 - interruptType info is 0x00010000 - PCI Dext interrupt final value, return status info is 0x00000000 UserStartController() - End Any assistance would be greatly appreciated! Thank you in advance for your support. Best regards, Charles
1
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358
Mar ’25
Inconsistent KEXT Status Between System Information and kextstat
Hello Everyone, I have noticed an inconsistency in the KEXT status between the System Information Extensions section and the output of the kextstat command. In System Information, the extension appears as loaded: ACS6x: Version: 3.8.3 Last Modified: 2025/3/10, 8:03 PM Bundle ID: com.Accusys.driver.Acxxx Loaded: Yes Get Info String: ACS6x 3.8.4 Copyright (c) 2004-2020 Accusys, Ltd. Architectures: arm64e 64-Bit (Intel): No Location: /Library/Extensions/ACS6x.kext/ Kext Version: 3.8.3 Load Address: 0 Loadable: Yes Dependencies: Satisfied Signed by: Developer ID Application: Accusys, Inc (K3TDMD9Y6B) Issuer: Developer ID Certification Authority Signing time: 2025-03-10 12:03:20 +0000 Identifier: com.Accusys.driver.Acxxx TeamID: K3TDMD9Y6B However, when I check using kextstat, it does not appear as loaded: $ kextstat | grep ACS6x Executing: /usr/bin/kmutil showloaded No variant specified, falling back to release I use a script to do these jobs echo " Change to build/Release" echo " CodeSign ACS6x.kext" echo " Compress to zip file" echo " Notary & Staple" echo " Unload the old Acxxx Driver" echo " Copy ACS6x.kext driver to /Library/Extensions/" echo " Change ACS6x.kext driver owner" echo " Loaded ACS6x.kext driver" sudo kextload ACS6x.kext echo " Rebiuld system cache" sudo kextcache -system-prelinked-kernel sudo kextcache -system-caches sudo kextcache -i / echo " Reboot" sudo reboot But it seems that the KEXT is not always loaded successfully. What did I forget to do? Any help would be greatly appreciated. Best regards, Charles
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264
Mar ’25
Assistance Needed for Migrating KEXT Delay Code to DriverKit
Hello Everyone, I am working on migrating a KEXT to DriverKit but am struggling to resolve a specific issue. The code in question is simple, but I haven't been able to find a solution. void AME_IO_milliseconds_Delay(AME_U32 Delay) { Log("AME_IO_milliseconds_Delay()"); IOSleep(Delay); return; } //delay for a number of microseconds void AME_IO_microseconds_Delay(AME_U32 Delay) { Log("AME_IO_microseconds_Delay()"); IODelay(Delay); return; } I've sought help from Copilot and ChatGPT, but their suggestions haven't worked. Any guidance on how to implement this functionality in DriverKit would be greatly appreciated. Thank you for your time and assistance. Best regards, Charles
1
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226
Mar ’25
CoreAudio server plugin: propagate kAudioObjectPropertyName change
When my virtual CoreAudio server plugins propagates a change to it´s device name the CoreAudio system does not seem to reflect the change. My user mode application subscribes to the property change and receives the change though. I also alternatively submitted a kAudioObjectPropertyName change with the same effect. Is this possible at all and what needs to be done then? Are there restrictions about which properties can be successfully changed and are reflected by the system? Any hint is highly appreciated! Thanks
1
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60
Mar ’25
How to setup DriverKit Timer Event with OSAction Callback Binding
Hello Everyone, I'm encountering an issue while setting up a timer event in DriverKit and would appreciate any guidance. Here's my current implementation: void DRV_MAIN_CLASS_NAME::SetupEventTimer() { // 1. Create dispatch queue kern_return_t ret = IODispatchQueue::Create("TimerQueue", 0, 0, &ivars->dispatchQueue); if (ret != kIOReturnSuccess) { LogErr("Failed to create dispatch queue: 0x%x", ret); return; } // 2. Create timer source ret = IOTimerDispatchSource::Create(ivars->dispatchQueue, &ivars->dispatchSource); if (ret != kIOReturnSuccess) { LogErr("Failed to create timer: 0x%x", ret); OSSafeReleaseNULL(ivars->dispatchQueue); return; } /*! * @brief Create an instance of OSAction. * @discussion Methods to allocate an OSAction instance are generated for each method defined in a class with * a TYPE attribute, so there should not be any need to directly call OSAction::Create(). * @param target OSObject to receive the callback. This object will be retained until the OSAction is * canceled or freed. * @param targetmsgid Generated message ID for the target method. * @param msgid Generated message ID for the method invoked by the receiver of the OSAction * to generate the callback. * @param referenceSize Size of additional state structure available to the creator of the OSAction * with GetReference. * @param action Created OSAction with +1 retain count to be released by the caller. * @return kIOReturnSuccess on success. See IOReturn.h for error codes. */ // 3: Create an OSAction for the TimerOccurred method // THIS IS WHERE I NEED HELP OSAction* timerAction = nullptr; ret = OSAction::Create(this, 0, 0, 0, &timerAction); if (ret != kIOReturnSuccess) { LogErr("Failed to create OSAction: 0x%x", ret); goto cleanup; } // 4. Set handler ret = ivars->dispatchSource->SetHandler(timerAction); if (ret != kIOReturnSuccess) { LogErr("Failed to set handler: 0x%x", ret); goto cleanup; } // 5. Schedule timer (1 second) uint64_t deadline = mach_absolute_time() + NSEC_PER_SEC; ivars->dispatchSource->WakeAtTime(0, deadline, 0); cleanup: if (ret != kIOReturnSuccess) { OSSafeReleaseNULL(timerAction); OSSafeReleaseNULL(ivars->dispatchSource); OSSafeReleaseNULL(ivars->dispatchQueue); } } Problem: The code runs but the OSAction callback binding seems incorrect (Step 3). According to the OSAction documentation, I need to use the TYPE macro to properly bind the callback method. But I try to use TYPE(DRV_MAIN_CLASS_NAME::TimerOccurred) kern_return_t TimerOccurred() LOCALONLY; TYPE(TimerOccurred) kern_return_t TimerOccurred() LOCALONLY; kern_return_t TimerOccurred() TYPE(DRV_MAIN_CLASS_NAME::TimerOccurred) LOCALONLY; All results in Out-of-line definition of 'TimerOccurred' does not match any declaration in 'DRV_MAIN_CLASS_NAME' Questions: What is the correct way to declare a timer callback method using TYPE? How to get the values targetmsgid & msgid generated by Xcode? Any help would be greatly appreciated! Best Regards, Charles
6
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319
Apr ’25
Does USB Audio in macOS support 12 channels with 16bit PCM samples?
I have a custom USB Audio Class 2 (UAC2) compatible device. When I connect this custom device to a MacBook with a configuration of up to 10 channels (16-bit), everything seems to work fine. However, when I increase the channel count to 12, the MacBook does not recognize the 12 channels. It only shows the channel count as 0. TN2274 is the only source where I found some information about Apple's Audio Class Drivers, but it doesn't mention any limitations regarding channel counts. Could you let me know the current limitations of the Audio Class Drivers on the latest macOS versions? What configuration should I use to get 12 channels working? P.S. I also found that a 12-channel, 8-bit configuration is detected by the MacBook, bit I want it to work with 16bits. For more detail please check FB17098863
6
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197
Apr ’25
Endpoint security system extension
When I develop the system extension tool, I need to subscribe to the remote thread creation event. When the remote thread injection is triggered, I want to get the id, module name and starting function name of the remote thread. How can I get this information from es_event_remote_thread_create_t? If I can't get this information from es_event_remote_thread_create_t, is there any other way to get it?
1
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64
Apr ’25
Cannot enable Calldirectory Extension
Hello, I recently created an app with the Calldirectory Extension. It worked all good as long as I was on my development iphone. I tried to install the app on my privat iphone (same phone/same os version), but then I faced an issue. I couldn't enable the Calldirectory Extension with an error (Error Enabling Extension Failed to request data for APPNAME. You may try enabling the extension again, and if the problem persists, conatact the application developer.)
1
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68
Apr ’25
Cleaning up CoreAudio preferences
Hi, our virtual CoreAudio server plugin creates and removes dynamically CoreAudio devices. Each time it does so it leaves traces in /Library/Preferences/Audio com.apple.audio.DeviceSettings.plist com.apple.audio.SystemSettings.plist The files on the test machine now have become >1Mb and the system keeps recreating them. How can I manually remove/cleanup these files? (This is for development only. It already became pretty tedious to evaluate current device settings for debugging purposes.) How can the CoreAudio server plugin make sure once a device has been removed also its entries are removed from the .plist (It already removes it's storage, but the system still keeps other settings.) Is there some documentation about what gets stored and how the settings are organized in these preferences? (This is also for development and debugging only. We are not intending to access these settings directly ) Thanks!
5
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175
Apr ’25
Multiple thunderbolt device connected by daisy chain.
Hello everyone. I have been developing PCIe device driver through Thunderbolt. However, it was confirmed that up to three devices connected to the daisy chain worked normally, but the fourth device failed to operate the _CopyDeviceMemoryWithIndex() function for connection with the BAR0 App and did not work properly. The standard specification of Thunderbolt 3/4 is said to be supported by daisy chain connection up to 6-device, but in reality, it is only 3 units, so I ask the forum for technical confirmation. Of course total 4 device by 2-port x 2-device daisy chain connecting has working well. The PCI entry in System information indicates that all devices have normal load of the PCIe device driver. Thank you.
2
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77
Apr ’25
How to Reliably Detect DriverKit Support on iPad Devices
We’re looking for a reliable way to determine whether an iPad device supports DriverKit. Since there doesn't appear to be a direct public API for this, our current approach is as follows: Retrieve the device’s model identifier (e.g., "iPad14,8") and the iOS/iPadOS version. Map the model identifier to a known iPad model and its associated chip. If the device has an M-series chip, we assume it supports DriverKit. For future-proofing, we plan to assume that any future iPad with a model identifier of iPad15,* or higher will contain an M-series chip and therefore support DriverKit. We have a couple of questions: Is there a more reliable or official API to determine the chip version or DriverKit support? Is it reasonable to rely on the assumptions outlined in steps 2 and 3 for determining DriverKit compatibility?
2
0
113
May ’25