What: /sys/bus/thunderbolt/devices/.../domainX/boot_acl Date: Jun 2018 KernelVersion: 4.17 Contact: Mika Westerberg Description: Holds a comma separated list of device unique_ids that are allowed to be connected automatically during system startup (e.g boot devices). The list always contains maximum supported number of unique_ids where unused entries are empty. This allows the userspace software to determine how many entries the controller supports. If there are multiple controllers, each controller has its own ACL list and size may be different between the controllers. System BIOS may have an option "Preboot ACL" or similar that needs to be selected before this list is taken into consideration. Software always updates a full list in each write. If a device is authorized automatically during boot its boot attribute is set to 1. What: /sys/bus/thunderbolt/devices/.../domainX/deauthorization Date: May 2021 KernelVersion: 5.12 Contact: Mika Westerberg Description: This attribute tells whether the system supports de-authorization of devices. Value of 1 means user can de-authorize PCIe tunnel by writing 0 to authorized attribute under each device. What: /sys/bus/thunderbolt/devices/.../domainX/iommu_dma_protection Date: Mar 2019 KernelVersion: 4.21 Contact: Mika Westerberg Description: This attribute tells whether the system uses IOMMU for DMA protection. Value of 1 means IOMMU is used 0 means it is not (DMA protection is solely based on Thunderbolt security levels). What: /sys/bus/thunderbolt/devices/.../domainX/security Date: Sep 2017 KernelVersion: 4.13 Contact: Mika Westerberg Description: This attribute holds current Thunderbolt security level set by the system BIOS. Possible values are: ======= ================================================== none All devices are automatically authorized user Devices are only authorized based on writing appropriate value to the authorized attribute secure Require devices that support secure connect at minimum. User needs to authorize each device. dponly Automatically tunnel Display port (and USB). No PCIe tunnels are created. usbonly Automatically tunnel USB controller of the connected Thunderbolt dock (and Display Port). All PCIe links downstream of the dock are removed. nopcie USB4 system where PCIe tunneling is disabled from the BIOS. ======= ================================================== What: /sys/bus/thunderbolt/devices/.../authorized Date: Sep 2017 KernelVersion: 4.13 Contact: Mika Westerberg Description: This attribute is used to authorize Thunderbolt devices after they have been connected. If the device is not authorized, no PCIe devices are available to the system. Contents of this attribute will be 0 when the device is not yet authorized. Possible values are supported: == =================================================== 0 The device will be de-authorized (only supported if deauthorization attribute under domain contains 1) 1 The device will be authorized and connected == =================================================== When key attribute contains 32 byte hex string the possible values are: == ======================================================== 0 The device will be de-authorized (only supported if deauthorization attribute under domain contains 1) 1 The 32 byte hex string is added to the device NVM and the device is authorized. 2 Send a challenge based on the 32 byte hex string. If the challenge response from device is valid, the device is authorized. In case of failure errno will be ENOKEY if the device did not contain a key at all, and EKEYREJECTED if the challenge response did not match. == ======================================================== What: /sys/bus/thunderbolt/devices/.../boot Date: Jun 2018 KernelVersion: 4.17 Contact: Mika Westerberg Description: This attribute contains 1 if Thunderbolt device was already authorized on boot and 0 otherwise. What: /sys/bus/thunderbolt/devices/.../generation Date: Jan 2020 KernelVersion: 5.5 Contact: Christian Kellner Description: This attribute contains the generation of the Thunderbolt controller associated with the device. It will contain 4 for USB4. What: /sys/bus/thunderbolt/devices/.../key Date: Sep 2017 KernelVersion: 4.13 Contact: Mika Westerberg Description: When a devices supports Thunderbolt secure connect it will have this attribute. Writing 32 byte hex string changes authorization to use the secure connection method instead. Writing an empty string clears the key and regular connection method can be used again. What: /sys/bus/thunderbolt/devices/.../device Date: Sep 2017 KernelVersion: 4.13 Contact: Mika Westerberg Description: This attribute contains id of this device extracted from the device DROM. What: /sys/bus/thunderbolt/devices/.../device_name Date: Sep 2017 KernelVersion: 4.13 Contact: Mika Westerberg Description: This attribute contains name of this device extracted from the device DROM. What: /sys/bus/thunderbolt/devices/.../maxhopid Date: Jul 2021 KernelVersion: 5.13 Contact: Mika Westerberg Description: Only set for XDomains. The maximum HopID the other host supports as its input HopID. What: /sys/bus/thunderbolt/devices/.../rx_speed Date: Jan 2020 KernelVersion: 5.5 Contact: Mika Westerberg Description: This attribute reports the device RX speed per lane. All RX lanes run at the same speed. What: /sys/bus/thunderbolt/devices/.../rx_lanes Date: Jan 2020 KernelVersion: 5.5 Contact: Mika Westerberg Description: This attribute reports number of RX lanes the device is using simultaneously through its upstream port. What: /sys/bus/thunderbolt/devices/.../tx_speed Date: Jan 2020 KernelVersion: 5.5 Contact: Mika Westerberg Description: This attribute reports the TX speed per lane. All TX lanes run at the same speed. What: /sys/bus/thunderbolt/devices/.../tx_lanes Date: Jan 2020 KernelVersion: 5.5 Contact: Mika Westerberg Description: This attribute reports number of TX lanes the device is using simultaneously through its upstream port. What: /sys/bus/thunderbolt/devices/.../vendor Date: Sep 2017 KernelVersion: 4.13 Contact: Mika Westerberg Description: This attribute contains vendor id of this device extracted from the device DROM. What: /sys/bus/thunderbolt/devices/.../vendor_name Date: Sep 2017 KernelVersion: 4.13 Contact: Mika Westerberg Description: This attribute contains vendor name of this device extracted from the device DROM. What: /sys/bus/thunderbolt/devices/.../unique_id Date: Sep 2017 KernelVersion: 4.13 Contact: Mika Westerberg Description: This attribute contains unique_id string of this device. This is either read from hardware registers (UUID on newer hardware) or based on UID from the device DROM. Can be used to uniquely identify particular device. What: /sys/bus/thunderbolt/devices/.../nvm_version Date: Sep 2017 KernelVersion: 4.13 Contact: Mika Westerberg Description: If the device has upgradeable firmware the version number is available here. Format: %x.%x, major.minor. If the device is in safe mode reading the file returns -ENODATA instead as the NVM version is not available. What: /sys/bus/thunderbolt/devices/.../nvm_authenticate Date: Sep 2017 KernelVersion: 4.13 Contact: Mika Westerberg Description: When new NVM image is written to the non-active NVM area (through non_activeX NVMem device), the authentication procedure is started by writing to this file. If everything goes well, the device is restarted with the new NVM firmware. If the image verification fails an error code is returned instead. This file will accept writing values "1", "2" or "3". - Writing "1" will flush the image to the storage area and authenticate the image in one action. - Writing "2" will run some basic validation on the image and flush it to the storage area. - Writing "3" will authenticate the image that is currently written in the storage area. This is only supported with USB4 devices and retimers. When read holds status of the last authentication operation if an error occurred during the process. This is directly the status value from the DMA configuration based mailbox before the device is power cycled. Writing 0 here clears the status. What: /sys/bus/thunderbolt/devices/.../nvm_authenticate_on_disconnect Date: Oct 2020 KernelVersion: v5.9 Contact: Mario Limonciello Description: For supported devices, automatically authenticate the new Thunderbolt image when the device is disconnected from the host system. This file will accept writing values "1" or "2" - Writing "1" will flush the image to the storage area and prepare the device for authentication on disconnect. - Writing "2" will run some basic validation on the image and flush it to the storage area. What: /sys/bus/thunderbolt/devices/./key Date: Jan 2018 KernelVersion: 4.15 Contact: Mika Westerberg Description: This contains name of the property directory the XDomain service exposes. This entry describes the protocol in question. Following directories are already reserved by the Apple XDomain specification: ======== =============================================== network IP/ethernet over Thunderbolt targetdm Target disk mode protocol over Thunderbolt extdisp External display mode protocol over Thunderbolt ======== =============================================== What: /sys/bus/thunderbolt/devices/./modalias Date: Jan 2018 KernelVersion: 4.15 Contact: Mika Westerberg Description: Stores the same MODALIAS value emitted by uevent for the XDomain service. Format: tbtsvc:kSpNvNrN What: /sys/bus/thunderbolt/devices/./prtcid Date: Jan 2018 KernelVersion: 4.15 Contact: Mika Westerberg Description: This contains XDomain protocol identifier the XDomain service supports. What: /sys/bus/thunderbolt/devices/./prtcvers Date: Jan 2018 KernelVersion: 4.15 Contact: Mika Westerberg Description: This contains XDomain protocol version the XDomain service supports. What: /sys/bus/thunderbolt/devices/./prtcrevs Date: Jan 2018 KernelVersion: 4.15 Contact: Mika Westerberg Description: This contains XDomain software version the XDomain service supports. What: /sys/bus/thunderbolt/devices/./prtcstns Date: Jan 2018 KernelVersion: 4.15 Contact: Mika Westerberg Description: This contains XDomain service specific settings as bitmask. Format: %x What: /sys/bus/thunderbolt/devices/usb4_portX/connector Date: April 2022 Contact: Heikki Krogerus Description: Symlink to the USB Type-C connector. This link is only created when USB Type-C Connector Class is enabled, and only if the system firmware is capable of describing the connection between a port and its connector. What: /sys/bus/thunderbolt/devices/usb4_portX/link Date: Sep 2021 KernelVersion: v5.14 Contact: Mika Westerberg Description: Returns the current link mode. Possible values are "usb4", "tbt" and "none". What: /sys/bus/thunderbolt/devices/usb4_portX/offline Date: Sep 2021 KernelVersion: v5.14 Contact: Rajmohan Mani Description: Writing 1 to this attribute puts the USB4 port into offline mode. Only allowed when there is nothing connected to the port (link attribute returns "none"). Once the port is in offline mode it does not receive any hotplug events. This is used to update NVM firmware of on-board retimers. Writing 0 puts the port back to online mode. This attribute is only visible if the platform supports powering on retimers when there is no cable connected. What: /sys/bus/thunderbolt/devices/usb4_portX/rescan Date: Sep 2021 KernelVersion: v5.14 Contact: Rajmohan Mani Description: When the USB4 port is in offline mode writing 1 to this attribute forces rescan of the sideband for on-board retimers. Each retimer appear under the USB4 port as if the USB4 link was up. These retimers act in the same way as if the cable was connected so upgrading their NVM firmware can be done the usual way. What: /sys/bus/thunderbolt/devices/:./device Date: Oct 2020 KernelVersion: v5.9 Contact: Mika Westerberg Description: Retimer device identifier read from the hardware. What: /sys/bus/thunderbolt/devices/:./nvm_authenticate Date: Oct 2020 KernelVersion: v5.9 Contact: Mika Westerberg Description: When new NVM image is written to the non-active NVM area (through non_activeX NVMem device), the authentication procedure is started by writing 1 to this file. If everything goes well, the device is restarted with the new NVM firmware. If the image verification fails an error code is returned instead. When read holds status of the last authentication operation if an error occurred during the process. Format: %x. What: /sys/bus/thunderbolt/devices/:./nvm_version Date: Oct 2020 KernelVersion: v5.9 Contact: Mika Westerberg Description: Holds retimer NVM version number. Format: %x.%x, major.minor. What: /sys/bus/thunderbolt/devices/:./vendor Date: Oct 2020 KernelVersion: v5.9 Contact: Mika Westerberg Description: Retimer vendor identifier read from the hardware.