Thunderbolt support in Haiku

[VoloDroid]

What’s the current state of Thunderbolt support in Haiku?

I found PulkoMandy’s comment saying that Haiku didn’t support hotplugging and hot-unplugging of devices back in 2021. I guess that hasn’t changed since then, but does it mean that using of Thunderbolt devices plugged-in during the computer start-up should just work?

I have a MacBook Pro 2015 with Thunderbolt 2 ports that hangs during the bootup if I start it with this Thunderbolt-Ethernet adapter plugged in. I can also buy a Thunderbolt 2 cable + Thunderbolt 3 adapter to connect the laptop to an external Thunderbolt 3 disk enclosure, but the cable isn’t cheap (nor is the adapter), so before wasting money on it, I’d like to know if there’s a slight chance it might work.

[PulkoMandy]

@VoloDroid

I guess that hasn’t changed since then, but does it mean that using of Thunderbolt devices plugged-in during the computer start-up should just work?

My understanding is that from the OS side, Thunderbolt is similar enough to PCI and PCI-express that it may just work. But I have not tested it myself.

And yes, the hotplugging and hot-unplugging is still unsupported for now.

[VoloDroid]

“It may just work” is my assumption too, though I was reading about its security levels and thought that might require some sort of a driver in the OS. On that matter I’ve just found an interesting video talking about Thunderbolt on FreeBSD:
https://papers.freebsd.org/2020/bsdcan/long-thunderbolt_on_freebsd/

While the original intent was that OS-specific drivers would not be needed for peripherals to function, the reality is that a driver is needed to interact with the security features of the subsystem, flash firmware, and manage bandwidth and error handling.

and also in the video itself:

Thunderbolt Security Model requires a handshake between the OS and Connection Manager to approve/deny devices
Security model can be disabled in the BIOS

I have no idea if that Security Model is enabled on MacBook but most probably it is. I guess the only way to know it for sure is to buy the cable and test it.

[Zenja]

MacBookPro 11.3 (2014), Haiku supports Thunderbolt ethernet (broadcom 570x), but not hot plugging. Even Win10 (bootcamp) didnt support hotplugging when I last tested it years and years ago.

[VoloDroid]

@Zenja

MacBookPro 11.3 (2014) supports Thunderbolt ethernet (broadcom 570x), but not hot plugging.

That’s weird. According to this archived article from Apple:

Thunderbolt hot plug is supported under Windows 8 or 8.1 on all 2014 and later Mac computers

And hot plugging should be supported by MacOS itself, at least it works on my MacBook Pro 2015. In any case, for the time being I’m not interested in TB hot plugging under Haiku, first step would be just to make it work.

[Zenja]

Fixed logic error in my post, wanted to say Haiku doesnt support hot plugging.

[VoloDroid]

Now that’s interesting! Which Haiku version it worked with for you?