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; }

Dear Apple engineers and DriverKit developers, We have developed a DriverKit (DEXT) driver for an HBA RAID controller. The RAID controller is connected to hosts through Thunderbolt (PCIe port of the Thunderbolt controller). We use an IO script to verify the developed driver. The test fails after a few (10-12) hours of running with an error: “BUG IN CLIENT OF LIBDISPATCH: dispatch_sync called on queue already owned by current thread”. We inspected the stack trace of the crash report. This error happens in the interrupt handler. Thread 5 Crashed: 0 libdispatch.dylib 0x19671aa8c __DISPATCH_WAIT_FOR_QUEUE__ + 484 1 libdispatch.dylib 0x19671a5d0 _dispatch_sync_f_slow + 152 2 DriverKit 0x195d3fc1c IODispatchQueue::DispatchSync_f(void*, void (*)(void*)) + 296 3 DriverKit 0x195d40860 IOInterruptDispatchSourceThread(void*) + 380 4 libsystem_pthread.dylib 0x1968a3738 _pthread_start + 140 5 libsystem_pthread.dylib 0x1968ac6c8 thread_start + 8 On our side we created 5 DispatchQueue(s) for the interrupt processing and configured 5 interrupt handlers using ConfigureInterrupts(kIOInterruptTypePCIMessagedX, 1, 5). It gives 5 interrupts, as requested and it is not clear what is the reason for the issue. Our code samples are below uint32_t configureInterrupts(uint32_t requested, uint32_t required)  {      const kern_return_t ret = ioPCIdevice->ConfigureInterrupts(kIOInterruptTypePCIMessagedX, required, requested);      if (ret != kIOReturnSuccess)          return 0;      uint64_t interruptType = 0;      uint32_t interruptsCount = 0;      uint32_t interruptIndex = 0;        for ( ;; ++interruptIndex) {          if (IOInterruptDispatchSource::GetInterruptType(ioPCIdevice, interruptIndex, &interruptType) != kIOReturnSuccess)              break;          if ((interruptType & kIOInterruptTypePCIMessagedX) == 0)              continue;          ++interruptsCount;      }      return interruptsCount;  }  ..... // Create DQs     for(int i = 0; i < maxInterrupts; ++i) {          ret = IODispatchQueue::Create(INTERRUPT_DQ_NAME, 0, 0, &ivars->interruptQueue[i]);          if (kIOReturnSuccess != ret || nullptr == ivars->interruptQueue[i]) {              GH_PRINT_ERR("Interrupts queue %d creation failed with error %d", i, ret);              return false;          }      } ..... // Link DQ with interrupt   for(int index = 0; index < maxInterrupts; ++ index) {      kern_return_t ret = CreateActionHandleInterruptRequest(size, &ivars->interruptActions[index]);      if (kIOReturnSuccess != ret) {          GH_PRINT_ERR("Create action for interrupt handler %u failed.", index);          return ;      }      ret = IOInterruptDispatchSource::Create(ivars->PCI_io.dev, index, ivars->interruptQueue[index], &ivars->interruptSources[index]);      if (kIOReturnSuccess != ret || nullptr == ivars->interruptSources[index]) {          GH_PRINT_ERR("Creating interrupt source %u failed for interrupt index %u.", index, index);          return ;      }      ret = ivars->interruptSources[index]->SetHandler(ivars->interruptActions[index]);      if (kIOReturnSuccess != ret) {          GH_PRINT_ERR("Setting the handler for interrupt source %u failed.", index);          return ;      }      ivars->contexts[index] = ivars->interruptActions[index]->GetReference();      }  ..... // definition for interrupt handler void    HandleInterruptRequest ( OSAction *action, uint64_t count, uint64_t time) TYPE (IOInterruptDispatchSource::InterruptOccurred);  Do you have any clue how we can fix this error? Or directions and ways for investigation? Please let us know if you need more details.

Hello everybody, Since macOS 15, the systemextension allow in changed as switch style and put in the "Login items & Extensions". I know the URL navigating to here, which is: x-apple.systempreferences:com.apple.LoginItems-Settings.extension But the extension options we need to scroll deep down and we need to click the "!" to open it. I want to open the finally window for user can easily see it and enable it. Please tell me how. Appreciate!!

I have an iPhone 14 Pro. I downloaded the iOS 26 beta and had a SERIOUS error, rendering the phone unusable. I charged it to 60% and kept it plugged in while updating. While updating, I restarted several times at the Apple logo, then at the Welcome screen, and it had quite a few bugs with low battery warnings. When I turned it on, I noticed I had 1% (I thought it was strange). When it was plugged in, it wouldn't charge; it only had 1% left, and it also restarted every 2 minutes. Off-plugged, it did exactly the same thing. In the end, I had to go back to iOS 18.5; I had no problems with this version.

I am trying to localize the CFBundleDisplayName and OSBundleUsageDescription of a driver that is part of an app. I am able to use InfoPlist.strings files to localize the Bundle display name for the app, but when I try to use the same file as part of the driver, the name displayed in settings for the app does not change correctly. In fact, it seems to follow the default language set in the xcode project. If the default language is not included in the suite of InfoPlist.strings files, it seems to take the string from the info.plist file. sometimes it just seems to take the English version regardless of the default language or tablet language. Has anyone had success with this?

Hi guys! OK, reaching out for some help here. I am having all kinds of trouble with OSDeclareDefaultStructors. I have seriously been at this for nearly a week now and have come to the conclusion that I need to reach out for help from people that are more experience using Xcode. I believe entirely that my issue is just that I can't for whatever reason see how to set up includes and libraries and things like that. I have this line: OSDeclareDefaultStructors(NukeVirtualGamepad) No matter what I do, Xcode will not recognize OSDeclareDefaultStructors. The project builds a DriverKit &gt; Driver extension. I have literally tried absolutely everything with this. I am at a loss for words. I even set up a new blank project and it still will not recognize OSDeclareDefaultStructors. I did a lot of research and it looks like expo needs OSDeclareDefaultStructors in order for the extension to build with a binary in it instead of being just a codeless extension. Here is the code with the issue: #pragma once #include &lt;DriverKit/OSMetaClass.h&gt; #include &lt;HIDDriverKit/IOUserHIDDevice.h&gt; #include &lt;DriverKit/OSData.h&gt; class NukeVirtualGamepad : public IOUserHIDDevice { OSDeclareDefaultStructors(NukeVirtualGamepad) // The problem is right here! This line! public: // Keep it minimal; no 'override' keywords since the .h types may not mark them virtual bool init(); void free(); kern_return_t Start(IOService* provider); void Stop (IOService* provider); OSData* newReportDescriptor(); // (Optional) helper you’ll use later to inject input matching your report kern_return_t PostInput(uint16_t buttons, int8_t x, int8_t y); }; I do have to mention to everyone that I am still very new with Xcode. So there is a ton that I don't know yet or might be misunderstanding. Has anyone seen this before? Thank you in advance.

The device I am trying to develop a firmware updater for is an NVMe drive with a USB4 interface. It can connect in USB4 mode (tunneled NVMe), in USB 3 mode or in USB 2 mode. In USB 2 and USB 3 mode, the device descriptor shows one interface with two alternates. Alternate 0 uses the bulk-only protocol, with one IN and one OUT pipe. Alternate 1 uses the UAS protocol, with two IN and two OUT pipes. I use identical code in my driver to send custom CDBs. I can see using IORegistryExplorer that in USB 2 mode, macOS chooses alternate 0, the bulk-only protocol. My custom CDBs and their accompanying data pay loads are put on the bus, more or less as expected. In USB 3 mode, macOS chooses alternate 1, the UAS protocol. My custom CDB is put on the bus, but no payload data is transferred. Is this expected behavior? If so, is there a way to force the OS to choose alternate 0 even when on USB 3, perhaps with another dext? I'll file a bug about this when Feedback Assistant lets me.

Hi, We are using the AX88772C as a USB->Ethernet bridge in a product we are developing. Due to the chip not following the NCM protocol, it is not supported by the default networking drivers on the iPhone. Initially, we intended on using DriverKit to develop a userspace driver for this device. However, we have been informed DriverKit is only available on iPad OS, not iOS. As such is the case, we have found two possible alternatives. First being IOkit, and the second being External Accessory Session (EASession). What are the limitations of each of these options? We need the ability to send and receive USB packets to Control and Bulk endpoints. Is this possible with either of the options defined above? Would either of these options require the device to be MFi certified? We have read that some APIs within IOkit require the apple device to be jailbroken. Is there a list of features that can be used without a jailbroken device? Documentation on these 2 options is limited, so any official documentation would be great. Thanks!

Hello forum, I'm trying to build communications between a non-MFi HID device (say, a keyboard with a USB-C port) and an iOS device over a MFi-licensed cable with Swift, what framework would you suggest? The USB-C cable is MFi-licensed. The keyboard is not MFi-licensed.

Investigating a kernel panic, I discovered that Apple Silicon Panic traces are not working with how I know to symbolicate the panic information. I have not found proper documentation that corrects this situation. Attached file is an indentity-removed panic, received from causing an intentional panic (dereferencing nullptr), so that I know what functions to expect in the call stack. This is cut-and-pasted from the "Report To Apple" dialog that appears after the reboot: panic_1_4_21_b.txt To start, I download and install the matching KDK (in this case KDK_14.6.1_23G93.kdk), identified from this line: OS version: 23G93 Kernel version: Darwin Kernel Version 23.6.0: Mon Jul 29 21:14:04 PDT 2024; root:xnu-10063.141.2~1/RELEASE_ARM64_T8122 Then start lldb from Terminal, using this command: bash_prompt % lldb -arch arm64e /Library/Developer/KDKs/KDK_14.6.1_23G93.kdk/System/Library/Kernels/kernel.release.t8122 Next I load the remaining scripts per the instructions from lldb: (lldb) settings set target.load-script-from-symbol-file true I need to know what address to load my kext symbols to, which I read from this line of the panic log, after the @ symbol: com.company.product(1.4.21d119)[92BABD94-80A4-3F6D-857A-3240E4DA8009]@0xfffffe001203bfd0->0xfffffe00120533ab I am using a debug build of my kext, so the DWARF symbols are part of the binary. I use this line to load the symbols into the lldb session: (lldb) addkext -F /Library/Extensions/KextName.kext/Contents/MacOS/KextName 0xfffffe001203bfd0 And now I should be able to use lldb image lookup to identify pointers on the stack that land within my kext. For example, the current PC at the moment of the crash lands within the kext (expected, because it was intentional): (lldb) image lookup -a 0xfffffe001203fe10 Which gives the following incorrect result: Address: KextName[0x0000000000003e40] (KextName.__TEXT.__cstring + 14456) Summary: "ffer has %d retains\n" That's not even a program instruction - that's within a cstring. No, that cstring isn't involved in anything pertaining to the intentional panic I am expecting to see. Can someone please explain what I'm doing wrong and provide instructions that will give symbol information from a panic trace on an Apple Silicon Mac? Disclaimers: Yes I know IOPCIFamily is deprecated, I am in process of transitioning to DriverKit Dext from IOKit kext. Until then I must maintain the kext. Terminal command "atos" provides similar incorrect results, and seems to not work with debug-built-binaries (only dSYM files) Yes this is an intentional panic so that I can verify the symbolicate process before I move on to investigating an unexpected panic I have set nvram boot-args to include keepsyms=1 I have tried (lldb) command script import lldb.macosx but get a result of error: no images in crash log (after the nvram settings)

I have two different USB devices with different vendor IDs I would like to connect to. I submitted two separate requests for the com.apple.developer.driverkit.transport.usb entitlement for each vendor ID. However I am noticing the provisioning profile only has one of the vendor IDs. How do I submit a request for the USB Transport entitlement to support more than one vendor ID? I'm new to writing a DriverKit driver, so is this even possible?

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?

I have an app that captures USB storage device and sends some commands to it. The app has a privilege helper tool which captures the USB device. Everything was working fine upto macOS 15.2 but it 15.3 update broke the functionality. When the helper tool tries to capture the USB device, it is able to capture IOUSBHostDevice but fails to capture IOUSBHostInterface. The error is Code: 3758097097; Domain: IOUSBHostErrorDomain; Description: Failed to create IOUSBHostInterface.; Reason: Failed [super init] I have verified the UID, EUID, GID, EGID = 0 for the helper process. So by IOUSBHost documentation it should have worked. The code that cause the error inside the helper tool is func captureUSBInterface(interface: io_service_t) -> IOUSBHostInterface? { let queue = DispatchQueue(label: "com.example.usbdevice.queue2") var capturedInterface: IOUSBHostInterface? do { capturedInterface = try IOUSBHostInterface(__ioService: interface, options: .deviceCapture, queue: queue, interestHandler: nil) } catch { NSLog("Failed to capture USB interface: \(error)") return nil } return capturedInterface } The app has sandbox=False and is distributed outside of the App Store. Please advise (long-term, short-term solutions) on how to make this work.

Hello, We are experiencing some issues with our USB accessory unexpectedly charging the iOS device it is connected with only when the iOS device supports USB-C and is on iOS 18+ The following is a description of the discrepancy we note between iOS versions: After performing a USB Role switch, our Accessory becomes a typical USB Device and the Apple device becomes the USB host. with iOS 17: 
 The Accessory then sends a PowerSourceUpdate message to the iOS 17 device via iAP2 protocol. Apple device has a USB Type C Connector. * We are specifying: AvailableCurrentForDevice = 0 mA  DeviceBatteryShouldChargeIfPowerIsPresent = 1. Three observations: iPad Battery Settings page -  we observe  'Last charged to…' (indicating no charging) On the Lumify App running (iOS 17), we observe that UIKit.current.batteryState indicated 'Not charging' Battery icon on top right of the screen indicates 'No Charging' with iOS 18: The same Accessory sends the same PowerSourceUpdate message to the iOS 18 device via iAP2 protocol using USB Type C Connector. We are specifying the same: AvailableCurrentForDevice = 0 mA DeviceBatteryShouldChargeIfPowerIsPresent = 1. We observe: iPad Battery Settings page -  we observe  'Charging'  On the Lumify App running (iOS 18), we observe that UIKit.current.batteryState indicated 'Charging' Battery icon on top right of the screen indicates 'No Charging' Please could you help us understand why the Battery status is showing as 'Charging' in the Settings page and with the 'UIKit.current.batteryState' even though we have specified 'AvailableCurrentForDevice = 0 mA'?
 Since our accessory is heavily reliant on the Battery status / Charging state, is there potentially another way we get an accurate battery charging status that we are missing? Or are there other suggestions outside of what we do currently to ensure our accessory does not place the iOS18 device into a charging state?

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!

Hi, I have a usb composite device with multiple interfaces that support cdc-acm UARTs. My custom driver (.dext) loads and works for single channel usb-cdcccm device with these entries in the info.plist: bInterfaceNumber 1 But there is no option to define multiple "bInterfaceNumber" key. I tried bInterfaceClass also, as given below, but no success. Option-1: bInterfaceClass 10 bInterfaceSubClass 0 bInterfaceProtocol 0 Option-2: bInterfaceClass 10 bInterfaceSubClass 0 bInterfaceProtocol 0 Both the above options yield no result. But as I said in the beginning: <key>IOProviderClass</key> <string>IOUSBHostInterface</string> <key>IOClass</key> <string>IOUserSerial</string> <key>IOResourceMatch</key> <string>IOKit</string> <key>IOUserClass</key> <string>MyDriver</string> <key>IOUserServerName</key> <string>$(PRODUCT_BUNDLE_IDENTIFIER)</string> <key>idVendor</key> <integer>VENDORID</integer> <key>idProduct</key> <integer>PRODUCTID</integer> <key>bInterfaceNumber</key> <integer>1</integer> <key>bConfigurationValue</key> <integer>1</integer> "MyDriver" loads for interface-1 and works fine. The default AppleCDCACM driver loads for the 2nd channel. I want the same driver load for both the channels. Any help/suggestions \is very much appreciated. Thank you.

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.

Hello, forum, I'm trying to build connection between a non-MFi HID device (like keyboard) and iOS app with IOKit and Swift. Thanks to this post, I have manage to import the IOKit into objc header. IOKit on iOS/iPadOS 16.0+ #import <IOKit/IOKitLib.h> However, I have this compiler error when I try to imitate same methods in the SerialPortSaple project from following article, but the IOKit can not be imported to Swift at first place. Communicating with a Modem on a Serial Port The screen shot of the sample project: It looks like the complier unable to reach the io_object_t type somehow, is there any workaround or approach?

Hi, I am trying to develop MacOS application which will be connecting to USB devices and should be available in AppStore. So it must be Sandbox and probably I've to use permission com.apple.security.device.usb. I've following requirements: I need to detect USB devices with file system I need to have ability to upload & download files from this device I need to read device serial number I wonder if I can use IOKit for this and it will be compliant with AppStore rules or not?

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