Hi, Is it possible for a macOS (or iOS/ipadOS) app to communicate with a CCID-compliant reader using the CCID interface (i.e., directly sending the PC_TO_RDR_* messages) instead of using the CryptoTokenKit API? Apple's CCID driver (/System/Library/CryptoTokenKit/usbsmartcardreaderd.slotd) seems to support all the PC_TO_RDR and RDR_TO_PC messages: https://blog.apdu.fr/posts/2023/11/apple-own-ccid-driver-in-sonoma/#enable-my-ccid-driver The background for this question is that we develop smartcard products and we'd like to use the finer grained settings provided by the CCID specification for testing/demo purposes. Thank you.

While developing our driver, we've noticed that the *.ips report that contains the stacktrace of the crash is not always generated. I'm wondering why this report may not get generated, or if there's anything specific to do to guarantee it gets generated.

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!

I want to turn off this effect and maintain the style before iOS18. Do I need to add content about iOS26 to the info.plist? Specifically, which content is it? I want to turn off the glass effect on the button

Hi everyone, We are in the process of migrating a legacy KEXT for our external multi-disk RAID enclosure to the modern DriverKit framework. During the performance validation of our KEXT, we observed a large and consistent maximum throughput difference between Intel-based Macs and Apple Silicon-based Macs. We would like to share our findings and hope to discuss with others in the community to see if you have had similar experiences that could confirm or correct our understanding. The Observation: A Consistent Performance Gap When using the exact same external RAID hardware (an 8-HDD RAID 5 array), driven by our mature KEXT, we see the following results in high-throughput benchmarks (AJA System Test, large sequential writes): On a 2020 Intel-based Mac: We consistently achieve a throughput of ~2500 MB/s. On modern M-series Macs (from M1 to M4): The throughput is consistently capped at ~1500 MB/s. This performance difference of nearly 40% is significant and is present across the entire Apple Silicon product line. Our Hypothesis: A Shift in Architectural Design Philosophy Since the KEXT and external hardware are identical in both tests, we believe this performance difference is not a bug but a fundamental platform architecture distinction. Our hypothesis is as follows: 1. The Intel Mac Era ("Dedicated Throughput") The Intel-based Macs we tested use a dedicated, discrete Intel Thunderbolt controller chip. This chip has its own dedicated PCIe lanes and resources, and its design appears to be singularly focused on maximizing raw, sustained data throughput for external peripherals. 2. The Apple Silicon Era ("Integrated Efficiency") In contrast, M-series Macs use a deeply integrated I/O controller inside the SoC. This controller must share resources, such as the total unified memory bandwidth and the chip's overall power budget, with all other functional units (CPU, GPU, etc.). We speculate that the design priority for this integrated I/O controller has shifted from "maximizing single-task raw throughput" to "maximizing overall system efficiency, multi-task responsiveness, and low latency." As a result, in a pure, single-task storage benchmark, its performance ceiling may be lower than that of the older, dedicated-chip architecture. Our Question to the Community: Is our understanding correct? Have other developers of high-performance storage drivers or peripherals also observed a similar performance ceiling for external storage on Apple Silicon Macs, when compared to high-end Intel Macs? We believe that understanding this as a deliberate architectural trade-off is crucial for setting realistic performance targets for our DEXT. Our current goal has been adjusted to have our DEXT match the KEXT's ~1500 MB/s on the M-series platform. Any insights, confirmations, or corrections from the community or Apple engineers would be greatly appreciated. Thank you very much! Charles

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.

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?

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?

Kevin's Guide to DEXT Signing The question of "How do I sign a DEXT" comes up a lot, so this post is my attempt to describe both what the issues are and the best current solutions are. So... The Problems: When DEXTs were originally introduced, the recommended development signing process required disabling SIP and local signing. There is a newer, much simpler process that's built on Xcode's integrated code-signing support; however, that newer process has not yet been integrated into the documentation library. In addition, while the older flow still works, many of the details it describes are no longer correct due to changes to Xcode and the developer portal. DriverKit's use of individually customized entitlements is different than the other entitlements on our platform, and Xcode's support for it is somewhat incomplete and buggy. The situation has improved considerably over time, particularly from Xcode 15 and Xcode 16, but there are still issues that are not fully resolved. To address #1, we introduced "development" entitlement variants of all DriverKit entitlements. These entitlement variants are ONLY available in development-signed builds, but they're available on all paid developer accounts without any special approval. They also allow a DEXT to match against any hardware, greatly simplifying working with development or prototype hardware which may not match the configuration of a final product. Unfortunately, this also means that DEXT developers will always have at least two entitlement variants (the public development variant and the "private" approved entitlement), which is what then causes the problem I mentioned in #2. The Automatic Solution: If you're using Xcode 16 or above, then Xcode's Automatic code sign support will work all DEXT Families, with the exception of distribution signing the PCI and USB Families. For completeness, here is how that Automatic flow should work: Change the code signing configuration to "Automatic". Add the capability using Xcode. (USB & PCI) Edit your Entitlement.plist to include the correct "Development Only" configuration: USB Development Only Configuration: <key>com.apple.developer.driverkit.transport.usb</key> <array> <dict> <key>idVendor</key> <string>*</string> </dict> </array> PCI Development Only Configuration: <key>com.apple.developer.driverkit.transport.pci</key> <array> <dict> <key>IOPCIPrimaryMatch</key> <string>0xFFFFFFFF&amp;0x00000000</string> </dict> </array> If you've been approved for one of these entitlements, the one oddity you'll see is that adding your approved capability will add both the approved AND the development variant, while deleting either will delete both. This is a visual side effect of #2 above; however, aside from the exception described below, it can be ignored. Similarly, you can sign distribution builds by creating a build archive and then exporting the build using the standard Xcode flow. Debugging Automatic Code-signing In a new project, the flow I describe above should just work; however, if you're converting an existing project, you may get code signing errors, generally complaining about how the provisioning profile configuration doesn't match. In most cases, this happens because Xcode is choosing to reuse a previously downloaded profile with an older configuration instead of generating a new configuration which would then include the configuration changes you made. Currently, you can find these profile files in: ~/Library/Developer/Xcode/UserData/Provisioning Profiles ...which can make it easier to find and delete the specific profile (if you choose). However, one recommendation I'd have here is to not treat the contents of that folder as "precious" or special. What automatic code signing actually does is generate provisioning profiles "on demand", so if you delete an automatic profile... Xcode will just generate it again at the next build. Manually generating profiles is more cumbersome, but the solution there is to preserve them as a separate resource, probably as part of your project data, NOT to just "lose" them in the folder here. If they get deleted from Xcode's store, then you can just copy them back in from your own store (or using Xcode, which can manually download profiles as well). The advantage of this approach is that when profiles "pile up" over time (which they tend to do), you can just delete[1] all of them then let Xcode regenerate the ones you're actually trying to investigate. In terms of looking at their contents, TN3125: Inside Code Signing: Provisioning Profiles has the details of how to see exactly what's there. [1] Moving them somewhere else works too, but could indicate a fear of commitment. __ Kevin Elliott DTS Engineer, CoreOS/Hardware

Have a 2019 Ford Edge w/ Sync 3.4, wired carplay. Worked fine w/ iPhone 16 Pro on iOS 18. Upgraded to iPhone 17 Pro, came w/ iOS 26, carplay hasn't worked since. I've kept trying throughout new iOS 26 releases, lately with iOS 26.3 Public Beta 1, still not working. Have a long running issue with updates and system diagnostics as I've tried over the last few months: FB20739050 There is also a Apple support community thread with issues like this (and a ton of others) - my first post there was https://discussions.apple.com/thread/256138283?answerId=261613103022&sortBy=oldest_first#261613103022 I'm hoping here in the developer forums someone can maybe take a look at the feedback item and various system diagnostics to pin-point the issue. I'm a little concerned it's still not fixed this far into the follow-up point releases of iOS 26. Appreciate any help, thanks! --Chuck

Why hasn't the watchOS app updated immediately after the iPhone app was updated? It remains stuck in "Installing" status on the Apple Watch.

I am developing a macOS virtual audio device using an Audio Server Plug-In (HAL). I want the virtual device to be visible to all applications only when my main app is running, and completely hidden from all apps when the app is closed. The goal is to dynamically control device visibility based on app state without reinstalling the driver.What is the recommended way for the app to notify the HAL plug-in about its running or closed state ? Any guidance on best-practice architecture for this scenario would be appreciated.

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?

Since macOS 26.4 Beta 1, virtual HID devices created via DriverKit can no longer intercept key events from the built-in MacBook keyboard. External keyboards still work. This is confirmed and tracked here: https://github.com/pqrs-org/Karabiner-Elements/issues/4402 One possible lead (from LLM-assisted analysis of Apple's open-source IOHIDFamily code and cross-referencing community reports): macOS 26.4 Beta may have introduced or modified a security policy referred to as com.apple.iohid.protectedDeviceAccess, which could block IOHIDDeviceOpen for the Apple Internal Keyboard connected via SPI transport (AppleHIDTransportHIDDevice). This appears related to a "GamePolicy" check in IOHIDDeviceClass.m that gates whether processes can open HID devices. This has not been independently verified and may or may not be the root cause. This has far-reaching consequences. Karabiner-Elements alone has over 21,000 GitHub stars and is used by hundreds of thousands of macOS users for keyboard customization, accessibility workflows, ergonomic setups, and multilingual input. This change completely breaks its core functionality on any MacBook. Beyond Karabiner, this affects every developer building keyboard remapping, input customization, or accessibility tooling via DriverKit virtual HID devices — including commercial applications currently in development. I'd argue that the power and flexibility of keyboard customization on macOS is a genuine competitive advantage for the platform. Developers and power users choose Macs partly because tools like this exist. Restricting this capability would be detrimental to the ecosystem and to Apple's appeal among professional users. I'd like to understand: is this an intentional security change or a regression? If intentional, is there a migration path?

I have a driver extending IOUserUSBSerial and I want the device to show up as /dev/tty.mycustombasename-123 and /dev/cu. respectively. How can I achieve that?

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

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

I have two Macbook Pros: 14" M4 Pro (company) 16" M4 Max (personal) I work remote full-time and recently purchased 2 of the new Studio Display XDRs. Everything works perfectly however I chose to connect them to the M4 Max. I have a caldigit Element TB5 hub and can daisy chain both monitors through that perfectly. With that said, no matter how I plug them into the M4 Pro I can only ever get one to light up at a time. What I have tried to resolve it: Plug them in individually to the m4 pro Plug them in one at a time, force them to 60hz and then plug them both in. Daisy Chaining the displays Daisy Chaining the displays through the TB5 Hub Nothing works. Only one display comes on and its whichever is plugged in first. I have even tried lowering the refresh to as low as it goes on both manually then plugging them back in. Still nothing. From what I am reading it appears to be that the M4 Pro has 3 display lanes and when I plug the first studio display XDR it is using 2 lanes. If I go down to 60hz which is what the original studio display was, then it should theoretically go down to 1 display lane allowing a second to be plugged in. A bunch of people had the older studio display running 2x 5k ASD monitors on the M4 Pro. Now with the latest Studio Display XDR I am stuck. I was researching possibly editing the EDID of each to mimic the older studio display, but I don't know how to do that easily without BetterDisplay and right now I have no ability to install that. There is a chance I can get approval to run commands / BetterDisplay to get this working if a solution can be found. What I think the ultimate fix is for the firmware / macOS to realize the limitation, force the studio display XDR to 60hz when a second monitor is plugged in and they both would work. A single Studio Display XDR could run 120hz, but immediately upon plugging a second one it swaps to 60hz. I am completely fine with that scenario. I have found a few discussions about this topic with the main one being on apple discussions: https://discussions.apple.com/thread/256262701?sortBy=rank&answerId=261888577022 Someone sort of gave me this idea on Mac because they were trying to use the studio display XDR on windows and it appears to have worked with cloning an older ASD EDID on the new model: https://www.reddit.com/r/mac/comments/1s3ani5/got_studio_display_xdr_working_on_windows_pc_5k/ I don't really know what else to do. I opened a ticket with support. Case # 102853480566, but it went no where. I got disconnected during the first call after describing everything and when they reached back out they didn't even give me 2 seconds to pick up and they hung up and closed the ticket. I really don't want to return the displays because they are beautiful and work beautifully on the m4 max. They should work with 60hz on the m4 pro. Who / How / When can we get this resolved? I would be happy to work with an Apple dev / engineer to help resolve this.

Hi, our CoreAudio server plugin supports different clock sources. A switch might result in a change of the selectable sample rates (and other settings). On a clock source switch the plugin reconfigures the set of available kAudioStreamPropertyAvailablePhysicalFormats and announces the change via AudioServerPlugInHostInterface::PropertiesChanged(). However at least the Audio MIDI Setup seems to ignore to update it's UI. The changes are first reflected after selecting another device and re-selecting the device of interest. (Latest macOS, M4 macMini) Is this a bug? Or is our CoreAudio server plugin required to indicate the change in the list of available audio formats differently? Thanks!

VirtIO provides macOS VM users on Intel with integrations like Shared Folders, Shared Clipboard or Drag and Drop files. After updating VM to macOS 15.4, the VirtIO is no longer available, and we see that the functionality listed above doesn't work. Please fix it.