@eskimo , I am becoming convinced that Apple does not want user developed software to interface with the USB-C bus unless it is for a specific device. I also saw that there is a libUSBCfwflash library which seems, on the surface, to be a bit hypocritical of Apple. I am impressed by Apple’s hardware and many of the apps but truly discouraged when it comes to using it with the USB interface. I don’t understand why reading and writing to a USB device from user space should be limited or why Apple doesn’t give an option to disable that part of the Sandbox, like they do in OSX. The IOKit calls used in libUSB that I looked into exist in iPadOS but they are blocked from user access. The current RTL-SDR driver software supports about 30 different combinations of Device ID and Product ID. DriverKit isn’t broken but the entitlement process seems to be. Thanks for all of your help, @eskimo. I appreciate your support! Gene

@eskimo , thanks for your help! Do any of the approaches to escalating privileges work on iPadOS? It struck me that it might be possible to run a virtual machine on an M1 iPad with more USB access than a normal app.

VMWare Fusion supports “USB pass through” or at least the appearance of it

@BenjaminApple and @eskimo , IOUSBHost seems to be a part of Driver kit (i.e. also exists in iPadOS on an M processor). Is there something I can read that will explain how USB access should work on iPadOS ? I think I also read that the driver kit includes portions of IOKit and this has me further confused as to what should work and what should not work. Thanks for helping me steer through this

@eskimo , you said above that "The entitlements required to do this are available to all developers for development". I have not been able to figure out how to do that on iPadOS. (I believe that) iPadOS apps need to be signed and provisions provided and entitlements granted. It is possible to develop software for iPadOS that does not require Apple to grant entitlement for a specific USB device (to associate with a DEXT)? Or is there another approach? Or am I not understanding correctly? Thanks!!! Gene

Thank you again!