I'm trying to implement a virtual serial port driver for my ham radio projects which require emulating some serial port devices and I need to have a "backend" to translate the commands received by the virtual serial port into some network-based communications. I think the best way to do that is to subclass IOUserSerial? Based on the available docs on this class (https://developer.apple.com/documentation/serialdriverkit/iouserserial), I've done the basic implementation below. When the driver gets loaded, I can see sth like tty.serial-1000008DD in /dev and I can use picocom to do I/O on the virtual serial port. And I see TxDataAvailable() gets called every time I type a character in picocom. The problems are however, firstly, when TxDataAvailable() is called, the TX buffer is all-zero so although the driver knows there is some incoming data received from picocom, it cannot actually see the data in neither Tx/Rx buffers. Secondly, I couldn't figure out how to notify the system that there are data available for sending back to picocom. I call RxDataAvailable(), but nothing appears on picocom, and RxFreeSpaceAvailable() never gets called back. So I think I must be doing something wrong somewhere. Really appreciate it if anyone could point out how should I fix it, many thanks! VirtualSerialPortDriver.cpp: constexpr int bufferSize = 2048; using SerialPortInterface = driverkit::serial::SerialPortInterface; struct VirtualSerialPortDriver_IVars {     IOBufferMemoryDescriptor *ifmd, *rxq, *txq;     SerialPortInterface *interface;     uint64_t rx_buf, tx_buf;     bool dtr, rts; }; bool VirtualSerialPortDriver::init() {     bool result = false;     result = super::init();     if (result != true)     {         goto Exit;     }     ivars = IONewZero(VirtualSerialPortDriver_IVars, 1);     if (ivars == nullptr)     {         goto Exit;     }     kern_return_t ret;     ret = ivars->rxq->Create(kIOMemoryDirectionInOut, bufferSize, 0, &ivars->rxq);     if (ret != kIOReturnSuccess) {         goto Exit;     }     ret = ivars->txq->Create(kIOMemoryDirectionInOut, bufferSize, 0, &ivars->txq);     if (ret != kIOReturnSuccess) {         goto Exit;     }     IOAddressSegment ioaddrseg;     ivars->rxq->GetAddressRange(&ioaddrseg);     ivars->rx_buf = ioaddrseg.address;     ivars->txq->GetAddressRange(&ioaddrseg);     ivars->tx_buf = ioaddrseg.address;     return true; Exit:     return false; } kern_return_t IMPL(VirtualSerialPortDriver, HwActivate) {     kern_return_t ret;     ret = HwActivate(SUPERDISPATCH);     if (ret != kIOReturnSuccess) {         goto Exit;     }     // Loopback, set CTS to RTS, set DSR and DCD to DTR     ret = SetModemStatus(ivars->rts, ivars->dtr, false, ivars->dtr);     if (ret != kIOReturnSuccess) {         goto Exit;     } Exit:     return ret; } kern_return_t IMPL(VirtualSerialPortDriver, HwDeactivate) {     kern_return_t ret;     ret = HwDeactivate(SUPERDISPATCH);     if (ret != kIOReturnSuccess) {         goto Exit;     } Exit:     return ret; } kern_return_t IMPL(VirtualSerialPortDriver, Start) {     kern_return_t ret;   ret = Start(provider, SUPERDISPATCH);     if (ret != kIOReturnSuccess) {         return ret;     }     IOMemoryDescriptor *rxq_, *txq_;     ret = ConnectQueues(&ivars->ifmd, &rxq_, &txq_, ivars->rxq, ivars->txq, 0, 0, 11, 11);     if (ret != kIOReturnSuccess) {         return ret;     }     IOAddressSegment ioaddrseg;     ivars->ifmd->GetAddressRange(&ioaddrseg);     ivars->interface = reinterpret_cast<SerialPortInterface*>(ioaddrseg.address);     SerialPortInterface &intf = *ivars->interface;     ret = RegisterService();     if (ret != kIOReturnSuccess) {         goto Exit;     }     TxFreeSpaceAvailable(); Exit:     return ret; } void IMPL(VirtualSerialPortDriver, TxDataAvailable) {     SerialPortInterface &intf = *ivars->interface;     // Loopback     // FIXME consider wrapped case     size_t tx_buf_sz = intf.txPI - intf.txCI;     void *src = reinterpret_cast<void *>(ivars->tx_buf + intf.txCI); //    char src[] = "Hello, World!";     void *dest = reinterpret_cast<void *>(ivars->rx_buf + intf.rxPI);     memcpy(dest, src, tx_buf_sz);     intf.rxPI += tx_buf_sz;     RxDataAvailable();     intf.txCI = intf.txPI;     TxFreeSpaceAvailable();     Log("[TX Buf]: %{public}s", reinterpret_cast<char *>(ivars->tx_buf));     Log("[RX Buf]: %{public}s", reinterpret_cast<char *>(ivars->rx_buf)); // dmesg confirms both buffers are all-zero     Log("[TX] txPI: %d, txCI: %d, rxPI: %d, rxCI: %d, txqoffset: %d, rxqoffset: %d, txlogsz: %d, rxlogsz: %d",         intf.txPI, intf.txCI, intf.rxPI, intf.rxCI, intf.txqoffset, intf.rxqoffset, intf.txqlogsz, intf.rxqlogsz); } void IMPL(VirtualSerialPortDriver, RxFreeSpaceAvailable) {     Log("RxFreeSpaceAvailable() called!"); } kern_return_t   IMPL(VirtualSerialPortDriver,HwResetFIFO){     Log("HwResetFIFO() called with tx: %d, rx: %d!", tx, rx);     kern_return_t ret = kIOReturnSuccess;     return ret; } kern_return_t   IMPL(VirtualSerialPortDriver,HwSendBreak){     Log("HwSendBreak() called!");     kern_return_t ret = kIOReturnSuccess;     return ret; } kern_return_t   IMPL(VirtualSerialPortDriver,HwProgramUART){     Log("HwProgramUART() called, BaudRate: %u, nD: %d, nS: %d, P: %d!", baudRate, nDataBits, nHalfStopBits, parity);     kern_return_t ret = kIOReturnSuccess;     return ret; }      kern_return_t   IMPL(VirtualSerialPortDriver,HwProgramBaudRate){     Log("HwProgramBaudRate() called, BaudRate = %d!", baudRate);     kern_return_t ret = kIOReturnSuccess;     return ret; } kern_return_t   IMPL(VirtualSerialPortDriver,HwProgramMCR){     Log("HwProgramMCR() called, DTR: %d, RTS: %d!", dtr, rts);     ivars->dtr = dtr;     ivars->rts = rts;     kern_return_t ret = kIOReturnSuccess; Exit:     return ret; } kern_return_t  IMPL(VirtualSerialPortDriver, HwGetModemStatus){     *cts = ivars->rts;     *dsr = ivars->dtr;     *ri = false;     *dcd = ivars->dtr;     Log("HwGetModemStatus() called, returning CTS=%d, DSR=%d, RI=%d, DCD=%d!", *cts, *dsr, *ri, *dcd);     kern_return_t ret = kIOReturnSuccess;     return ret; } kern_return_t   IMPL(VirtualSerialPortDriver,HwProgramLatencyTimer){     Log("HwProgramLatencyTimer() called!");     kern_return_t ret = kIOReturnSuccess;     return ret; } kern_return_t   IMPL(VirtualSerialPortDriver,HwProgramFlowControl){     Log("HwProgramFlowControl() called! arg: %u, xon: %d, xoff: %d", arg, xon, xoff);     kern_return_t ret = kIOReturnSuccess; Exit:     return ret; }

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.

Few user space applications are available in market for example xnvme, but does not have any interaction with Admin Submission/Completion queues. Also IOCTLs are not very prominent . Is there any ways to get access to the native NVMe Mac driver source code? Thanks, hopefully we will get some positive response here.

How does VMWare access USB devices without have any specifics of the USB device? Does it use the same profile/entitlement process or does it take a different approach?

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?

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)

Hello team, I am using USBDriverKit and Driverkit framework in my application for communication of USB device. After updating my iPad OS to 18 public beta, I am unable to get option to enable drivers in my setting page of my application. However, I am able to see that options in developer beta version of iPad OS 18. Can anyone guide me, how should I proceed further as I am unable to use my USB devices.

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Hello, I'm developing a custom AU plugin that needs to connect to a DriverKit driver. Using the DriverKit sample (https://github.com/DanBurkhardt/DriverKitUserClientSample.git), I was able to get a standalone app to connect to the driver successfully. However, the AU plugin, running in a sandboxed host, isn't establishing the connection. I’ve already added the app sandbox entitlement, but it hasn’t helped. Any advice on what might be missing? TIA!

Is there an option to create a macOS filter driver for the IONVMeFamily Driver that would enable sending NVMe Admin commands( likes security send , security receive, Firmware download)? This approach would allow us to reuse the IO path provided by the family driver.

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!!

Hi everyone, Are there any new updates on communicating with iPhones via USB-C without needing an MFi chip, especially with the iPhone 15 or upcoming iPhone 16? I'm developing a custom accessory and wondering if the switch to USB-C has introduced any new possibilities for data communication without going through the MFi program. Thanks!

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my carplay is not sinking with iphone after up dating to iOS 18. I have honda ZRV. What is the issue and how to resolve?

Hi everyone. I have an iOS application for work with an MFi-certified device connected to the iPhone via USB-C. When I launch the app and attach the device, I can create an EASession and use the InputStream and OutputStream as usual. But if I attach the device before launching the app I can't use the InputStream and OutputStream, because the hasBytesAvailable and hasSpaceAvailable properties are always false. The NSStreamEventHasBytesAvailable and NSStreamEventHasSpaceAvailable events will never be triggered. After I re-attach the device, the streams open fine and I can interact with the device. What can be wrong with the case of attaching the device before the app launches?

Since updating to 18.0 & 18.1 I’ve have issues with CarPlay connected via usb, phone calls specifically where people would say I sound distant and robotic distortion. Tried other vehicles same issue new usb same issue, tried all recommendations with no success some one who refused to update theirs worked well without any issues I’m currently facing. Any suggestions or there gonna be an update that addresses this issue ?

Hello Currently, we are developing an application that collects measurement data from devices via USB port but we have some problems regarding input buffer size that might reduce the reading speed. The data size is quite big (~1.5 million bytes). For every read action, the app will check the available size in the input buffer by command: ioctl(serialPort.hHandle, FIONREAD, readBuffSize) Then that size will be passed as the desired size for the read command. Between read actions, there will be a short sleep (1 - 3 ms). Please confirm some points below: Regardless of the size of the measure data, the available size will only be up to 1020 bytes, is it expected? Is the above size OS defined or driver defined? Could we increase it? As we checked, there were some missing bytes between the measure data and the actual read data. Is there any chance that the data in the input buffer be overwritten while the read thread is in sleep? Any recommended technique that can increase reading speed while still maintaining the integrity of the data? Tested OS: Sonoma 14.5