So Ethernet over TB works. But only if the PC is powered on while the mac is already powered on and connected. After that hot plug worked. Even if I rebooted the pc.
The link speed is 20gbit/s over tb2.
The following UEFI settings are used:
Discrete TB support = enabled
TBT Vt-d base security = enabled
Thunderbolt boot support = enabled
Tbt dynamic AC/DC L1 = enabled
Wake from TB devices = On
Security Level = No Security(for testing purposes might turn on later, see also:
SW SMI on TBT hot-plug = enabled (seems to be a shutdown/power toggle thingy, nut sure)
ACPI notify on tbt hot-plug = enabled (power saving feature)
GPIO3 Force Pwr = On (This forces the tb card to provide power to the tb chip, even if no device
is connected. This is useful for firmware update without a tb device attached to the tb card.)
GPIO filter = disabled (this reduces electrical noise when plugging 12V usb devices)
Enable CLK REQ = enabled (This seems to be a clocking relevant feature)
Enable ASPM = disabled (warning this setting “=enabled” prevented windows from booting)
(This is a pcie power saving feature meant for mobile pcs.) ->
Enable LTR = enabled
Enable PTM = enabled
Enable TBT ASPM = disabled (this sets the supported levels of the power saving feature, does
nothing if the “Enable ASPM” is “=disabled”)
DTBT Controller 0/1 = enabled (I guess you can configure the two ports individually)
TBT Host Router = two port
Thunderbolt OS select:
Windows 10 Thunderbolt support = Enable + RTD3 (Enable is also called “TB native hot plug
support” while RTD3 is a kind of low power mode also is connected to hot plug support ->
I still don’t know what all of these settings do but if yes I’ll document it here.
Edit1: Okay if you put another tb device between the mac and the pc and create a daisy chain it will
detect either of the devices(which ever initializes first) and won’t recognize the other.
If you then reboot the windows pc will detect both the mac and the tb device. If you then try to hotplug the mac it will be recognized again. If you terminate the connection to the tb device in the middle both the tb device and the mac will not be recognized properly.(though the tb device might work despite that.)
This leads me to believe that the behviour of the thunderbolt card is very dependent on the devices connected at boot time of windows.
Now lets try why I’m here in the first place: targed disk mode, brb.
Edit2: When booting the mac into target disc mode the mac shows itself as a drive. While I tried using thunderbolt the mac wasn’t detected at all(why???).
But I have an old firewire 400 pcie card and a thunderbolt to firewire dongle. When using wirewire this method works and the mac shows up as a firewire drive- Btw- this is still windows.
Edit3: Target disc mode doesn’t show up in linux as well. The mac isn’t even detected at all. Maybe there is some special apple sauce like a proprietary driver which I don’t have under linux. Maybe it would show up under macOS(hopefully it’s not dependent on mac firmware). Have to try with a VM.
If someone knows more let me know. All Google knows is how to activate the target disc mode.
Networking over thunderbolt works fine between linux<->macOS and windows<->macOS.
While in Windows the link speed is advertised as 20gbit/s but speed testing shows 8-9gbit/s. Under linux it was closer to 9,5-9,8gbit/s.
Edit4: regarding the target disc mode which I will from now on abbreviate as “tdm”
This book mentions that the drive will be presented as a SCSI drive:
Edit5: I dropped the target disc drive approach, nothing I did made the drive show up and I’m out of ideas.
So I installed arch linux on a USB drive and booted the macbook from it. This worked out fine.
Now I need to get ethernet over thunderbolt between the two linux machines working.
This documentation suggests that I have to manually trigger the loading of the “thunderbolt-net” kernel module via:
sudo modprobe thunderbolt-net
This command gives me no output and doesn’t the support a verbose -v flag. Also the thunderbolt network device doesn’t show up in the network manager. I will post some questions in the linux subforum and report back here.