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Comment by CountSessine | Hacker News Reader

Interesting.

The company I worked for and our competitor VMWare both had to create small kexts to enable on-the-fly capture of USB devices. We both accessed USB devices from user-space, but we needed to put small kexts in the kernel to prevent class drivers from being automatically attached to general USB devices. There was really no race-free user-space way of doing this and Apple ignored our messages on their dev forums when we asked for assistance.

I wonder if they’ve added an interface for this? Or maybe promiscuous USB device control just isn’t going to be possible now?

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If I'm correctly guessing that you might have worked on Parallels, thank you for one of the best programs I've ever used. So many nice delightful touches, like their autodetection of USB devices and asking if I want to use them with the VM or the native system. Without Parallels I could never have used a Mac as my main machine.

I've since moved back to Windows, but I hope Parallels might make a Windows version. The Windows competitors aren't as good as their Mac versions, and painfully slow compared to Parallels running on my ancient MBP 2012.

> on my ancient MBP 2012

I still do all my work on one, fast as the day I bought it.

Why can't someone slap the XNU api onto Linux and create a runtime system that permits Apple's UX frameworks/libraries to be used by Linux developers (who will create more performant apps that do incredible things while maintaining the look-and-feel of the Macs that we once loved)? As long as we're booting Linux on machines bought at their local mall outlet or online store, I don't see the legal problem. Maybe a new generation of managers at Apple would even cooperate with such a Linux distribution (something like A/UX of yesteryear)?

Why can't someone slap the XNU api onto Linux

Probably because importing Mach messaging and VM APIs into the Linux kernel, and recreating IOKit and similar from scratch is a pretty major undertaking; the APSL isn't GPL-compatible, so using the existing XNU code and trying to make it fit into the Linux kernel isn't something that could ever be upstreamed. Aside from the fact that Linux's device model doesn't exactly map to IOKit well.

Then there are invariably plenty of assumptions that userland makes: launchd is probably assumed to have PID 1; all sorts of stuff like that.

Plus of course, there's the question of whether this would be inline with the EULA of Apple's userland…

There's always GNUStep if you want to write Cocoa apps in Objective-C on Linux. Somehow I have a feeling the APIs aren't what's been holding back Linux on the desktop.

Darling is a translation layer that does something similar [0]. Development has gone up and down over the years. One of the main pain points is the way Apple adopts, and then discards, a new GUI API every few years.

[0] https://www.darlinghq.org/

2011 with a disabled AMD GPU as a daily driver here. CPU passmark at 6000 so why not with a SSD.

Parallels’ way of handling USB is just perfect. I was trying to install RockBox firmware to my iPod Classic and the easiest solution was to use Windows XP in parallels. That’s when I realised how well it’s implemented! It first asked me if I wanted to attach usb with Windows VM or MacOS, and later I could even make it default. Very good UX.

Edit: Windows XP, because I still remember its Product Key. Ha. I probably reinstalled XP in my PC as a kid about a hundred times.

Does it start with FCKGW...? ;)

I think that's one of the several "free" product keys available online. Mine starts with Q3GQT and ends with XPKBW. :D

As a side note, the forums aren't the best place for that; the post could just be unseen by the people that matter. The appropriate channels are through Feedback Assistant and/or a technical support report (https://developer.apple.com/support/technical/) which has bit more visibility.

For things vaguely like this, the places I've worked had contacts within the company helping us to varying degrees. Apply was not one of these companies, and unless there's money or contracts are being signed, getting that contact is a challenge.

Sure, but for clarification the channels I noted are if you are any registered developer and don't have close contact.

Or Else the best place these days seems to be Twitter and getting other developers support.

Second this, you get two free Technical Support Incident requests per year as a registered developer, and you can purchase additional ones. We regularly file such requests and have always got timely and helpful responses.

VMware Fusion has a Tech Preview out since last week where the USB passthrough support is no longer done via a kernel extension.

See here: https://communities.vmware.com/servlet/JiveServlet/download/...

Ah - good to know and glad to hear it for the sake of my former colleagues; Apple had already redesigned the USB kernel interfaces to make this more difficult and I wasn’t sure how they were going to keep doing this at all.

Yes, they've added an interface for this. The latest tech preview of VMware Fusion is using this interface rather than their own kext: https://blogs.vmware.com/teamfusion/2020/01/fusion-tp20h1-in...

USBDriverKit can do this.

Isn't this feature what's blocking Bluetooth Passthrough on macOS Dolphin?

In FreeBSD and NetBSD there's a USB_IFACE_DRIVER_DETACH ioctl(). But things are very different on XNU. (-:

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