I am currently in the process of developing a DEXT for a USB based external mass storage device using the USBDriverKit framework. IOUSBHostInterface is used as the provider to communicate with the interface's endpoints and I am successful in it. As per the IOUSBHostInterface documentation, To use a host interface object, call Open to create a new session between the interface and your driver. After successfully opening your session, you can request information from the interface and set up pipes to communicate with the interface's endpoints. Remember to close the session you opened in the Stop method of your driver. However, calling Open gains exclusive access to the USB interface and does not allow other services to access the interface. Also, to let go of the exclusive access, Close method can be called but in the Stop method which is called only once during the lifecycle of the extension (when the DEXT is unloaded). As a result of this, Apple's mass storage related KEXTs (media and partition related specifically) do not match the interface and so the filesystem of the drive in question does not get mounted whenever the DEXT has matched the interface. Is this exclusive access a limitation of USBDriverkit or is there any way to get around this issue in this case?

In a project, I'm using the DriverKit(and HIDDriverKit) framework. I have encountered a problem in the connection between the client app and the driver, which is implemented by the "IOKit" framework. By calling the function "IOServiceGetMatchingServices" the value of "iterator" returns correctly and then communication with the driver is done. However, after releasing the version on the TestFlight, on some systems, the value of the "iterator" returned 0 and it is not possible to communicate with the driver. I checked the status of the activated driver with the command "systemextensionsctl list" and there are no problems on the driver side and the values of "Enabled" and "Active" are starred. AppSandbox = True, SIP: enable ret = IOServiceGetMatchingServices(kIOMainPortDefault, IOServiceNameMatching(dextIdentifier), &iterator); if (ret != kIOReturnSuccess) { goto fail; } while ((service = IOIteratorNext(iterator)) != IO_OBJECT_NULL) { ret = IOServiceOpen(service, mach_task_self(), 0, &connection); if(ret == kIOReturnSuccess) { break; } else { syslog(LOG_WARNING, "IDmelonLog LIB: Can't open service"); } IOObjectRelease(service); }

I am currently writing a iPadOS application to act as a companion to the desktop version that controls a piece of hardware via a USB CDC serial connection. Due to modern iPads having USB-C ports for the last 2 years and the ability to attach certain USB devices via adaptors since the origin of the 30pin doc connector I would expect protocol availability to be fairly complete. So then why is it that the headers required to use USB CDC serial don't exist and if you make them yourself you need to use illegal symbols so you can't upload it to App Store connect. Where as USB CDC ethernet has full support along with Bluetooth RFCOMM (rs232 serial over bluetooth) and even USB MIDI given that midi is a superset of serial. So why isn't there a USB CDC serial kit/api/even just allowing a data stream to the TTY/CU port? If there is a way please tell me what it is and point me to the documentation.