1 What: /sys/bus/thunderbolt/devices/.
2 Date: Jun 2018
3 KernelVersion: 4.17
4 Contact: Mika Westerberg <mika.westerber
5 Description: Holds a comma separated list o
6 are allowed to be connected au
7 startup (e.g boot devices). Th
8 maximum supported number of un
9 entries are empty. This allows
10 to determine how many entries
11 If there are multiple controll
12 its own ACL list and size may
13 controllers.
14
15 System BIOS may have an option
16 that needs to be selected befo
17 consideration.
18
19 Software always updates a full
20
21 If a device is authorized auto
22 boot attribute is set to 1.
23
24 What: /sys/bus/thunderbolt/devices/.
25 Date: May 2021
26 KernelVersion: 5.12
27 Contact: Mika Westerberg <mika.westerber
28 Description: This attribute tells whether t
29 de-authorization of devices. V
30 de-authorize PCIe tunnel by wr
31 attribute under each device.
32
33 What: /sys/bus/thunderbolt/devices/.
34 Date: Mar 2019
35 KernelVersion: 4.21
36 Contact: Mika Westerberg <mika.westerber
37 Description: This attribute tells whether t
38 for DMA protection. Value of 1
39 it is not (DMA protection is s
40 security levels).
41
42 What: /sys/bus/thunderbolt/devices/.
43 Date: Sep 2017
44 KernelVersion: 4.13
45 Contact: Mika Westerberg <mika.westerber
46 Description: This attribute holds current T
47 set by the system BIOS. Possib
48
49 ======= =====================
50 none All devices are autom
51 user Devices are only auth
52 appropriate value to
53 secure Require devices that
54 minimum. User needs t
55 dponly Automatically tunnel
56 PCIe tunnels are crea
57 usbonly Automatically tunnel
58 connected Thunderbolt
59 PCIe links downstream
60 nopcie USB4 system where PCI
61 the BIOS.
62 ======= =====================
63
64 What: /sys/bus/thunderbolt/devices/.
65 Date: Sep 2017
66 KernelVersion: 4.13
67 Contact: Mika Westerberg <mika.westerber
68 Description: This attribute is used to auth
69 after they have been connected
70 authorized, no PCIe devices ar
71
72 Contents of this attribute wil
73 yet authorized.
74
75 Possible values are supported:
76
77 == ==========================
78 0 The device will be de-auth
79 deauthorization attribute
80 1 The device will be authori
81 == ==========================
82
83 When key attribute contains 32
84 values are:
85
86 == ==========================
87 0 The device will be de-auth
88 deauthorization attribute
89 1 The 32 byte hex string is
90 the device is authorized.
91 2 Send a challenge based on
92 challenge response from de
93 authorized. In case of fai
94 the device did not contain
95 EKEYREJECTED if the challe
96 == ==========================
97
98 What: /sys/bus/thunderbolt/devices/.
99 Date: Jun 2018
100 KernelVersion: 4.17
101 Contact: Mika Westerberg <mika.westerber
102 Description: This attribute contains 1 if T
103 authorized on boot and 0 other
104
105 What: /sys/bus/thunderbolt/devices/.
106 Date: Jan 2020
107 KernelVersion: 5.5
108 Contact: Christian Kellner <christian@ke
109 Description: This attribute contains the ge
110 controller associated with the
111 for USB4.
112
113 What: /sys/bus/thunderbolt/devices/.
114 Date: Sep 2017
115 KernelVersion: 4.13
116 Contact: Mika Westerberg <mika.westerber
117 Description: When a devices supports Thunde
118 have this attribute. Writing 3
119 authorization to use the secur
120 Writing an empty string clears
121 method can be used again.
122
123 What: /sys/bus/thunderbolt/devices/.
124 Date: Sep 2017
125 KernelVersion: 4.13
126 Contact: Mika Westerberg <mika.westerber
127 Description: This attribute contains id of
128 the device DROM.
129
130 What: /sys/bus/thunderbolt/devices/.
131 Date: Sep 2017
132 KernelVersion: 4.13
133 Contact: Mika Westerberg <mika.westerber
134 Description: This attribute contains name o
135 the device DROM.
136
137 What: /sys/bus/thunderbolt/devices/.
138 Date: Jul 2021
139 KernelVersion: 5.13
140 Contact: Mika Westerberg <mika.westerber
141 Description: Only set for XDomains. The max
142 supports as its input HopID.
143
144 What: /sys/bus/thunderbolt/devices/.
145 Date: Jan 2020
146 KernelVersion: 5.5
147 Contact: Mika Westerberg <mika.westerber
148 Description: This attribute reports the dev
149 All RX lanes run at the same s
150
151 What: /sys/bus/thunderbolt/devices/.
152 Date: Jan 2020
153 KernelVersion: 5.5
154 Contact: Mika Westerberg <mika.westerber
155 Description: This attribute reports number
156 using simultaneously through i
157
158 What: /sys/bus/thunderbolt/devices/.
159 Date: Jan 2020
160 KernelVersion: 5.5
161 Contact: Mika Westerberg <mika.westerber
162 Description: This attribute reports the TX
163 All TX lanes run at the same s
164
165 What: /sys/bus/thunderbolt/devices/.
166 Date: Jan 2020
167 KernelVersion: 5.5
168 Contact: Mika Westerberg <mika.westerber
169 Description: This attribute reports number
170 using simultaneously through i
171
172 What: /sys/bus/thunderbolt/devices/.
173 Date: Sep 2017
174 KernelVersion: 4.13
175 Contact: Mika Westerberg <mika.westerber
176 Description: This attribute contains vendor
177 from the device DROM.
178
179 What: /sys/bus/thunderbolt/devices/.
180 Date: Sep 2017
181 KernelVersion: 4.13
182 Contact: Mika Westerberg <mika.westerber
183 Description: This attribute contains vendor
184 from the device DROM.
185
186 What: /sys/bus/thunderbolt/devices/.
187 Date: Sep 2017
188 KernelVersion: 4.13
189 Contact: Mika Westerberg <mika.westerber
190 Description: This attribute contains unique
191 This is either read from hardw
192 newer hardware) or based on UI
193 Can be used to uniquely identi
194
195 What: /sys/bus/thunderbolt/devices/.
196 Date: Sep 2017
197 KernelVersion: 4.13
198 Contact: Mika Westerberg <mika.westerber
199 Description: If the device has upgradeable
200 number is available here. Form
201 If the device is in safe mode
202 -ENODATA instead as the NVM ve
203
204 What: /sys/bus/thunderbolt/devices/.
205 Date: Sep 2017
206 KernelVersion: 4.13
207 Contact: Mika Westerberg <mika.westerber
208 Description: When new NVM image is written
209 area (through non_activeX NVMe
210 authentication procedure is st
211 this file.
212 If everything goes well, the d
213 restarted with the new NVM fir
214 verification fails an error co
215
216 This file will accept writing
217
218 - Writing "1" will flush the i
219 area and authenticate the im
220 - Writing "2" will run some ba
221 and flush it to the storage
222 - Writing "3" will authenticat
223 currently written in the sto
224 supported with USB4 devices
225
226 When read holds status of the
227 operation if an error occurred
228 is directly the status value f
229 based mailbox before the devic
230 0 here clears the status.
231
232 What: /sys/bus/thunderbolt/devices/.
233 Date: Oct 2020
234 KernelVersion: v5.9
235 Contact: Mario Limonciello <mario.limonc
236 Description: For supported devices, automat
237 image when the device is disco
238
239 This file will accept writing
240
241 - Writing "1" will flush the i
242 area and prepare the device
243 - Writing "2" will run some ba
244 and flush it to the storage
245
246 What: /sys/bus/thunderbolt/devices/<
247 Date: Jan 2018
248 KernelVersion: 4.15
249 Contact: Mika Westerberg <mika.westerber
250 Description: This contains name of the prop
251 service exposes. This entry de
252 question. Following directorie
253 the Apple XDomain specificatio
254
255 ======== ====================
256 network IP/ethernet over Thu
257 targetdm Target disk mode pro
258 extdisp External display mod
259 ======== ====================
260
261 What: /sys/bus/thunderbolt/devices/<
262 Date: Jan 2018
263 KernelVersion: 4.15
264 Contact: Mika Westerberg <mika.westerber
265 Description: Stores the same MODALIAS value
266 the XDomain service. Format: t
267
268 What: /sys/bus/thunderbolt/devices/<
269 Date: Jan 2018
270 KernelVersion: 4.15
271 Contact: Mika Westerberg <mika.westerber
272 Description: This contains XDomain protocol
273 service supports.
274
275 What: /sys/bus/thunderbolt/devices/<
276 Date: Jan 2018
277 KernelVersion: 4.15
278 Contact: Mika Westerberg <mika.westerber
279 Description: This contains XDomain protocol
280 service supports.
281
282 What: /sys/bus/thunderbolt/devices/<
283 Date: Jan 2018
284 KernelVersion: 4.15
285 Contact: Mika Westerberg <mika.westerber
286 Description: This contains XDomain software
287 service supports.
288
289 What: /sys/bus/thunderbolt/devices/<
290 Date: Jan 2018
291 KernelVersion: 4.15
292 Contact: Mika Westerberg <mika.westerber
293 Description: This contains XDomain service
294 bitmask. Format: %x
295
296 What: /sys/bus/thunderbolt/devices/u
297 Date: April 2022
298 Contact: Heikki Krogerus <heikki.krogeru
299 Description:
300 Symlink to the USB Type-C conn
301 created when USB Type-C Connec
302 and only if the system firmwar
303 describing the connection betw
304 connector.
305
306 What: /sys/bus/thunderbolt/devices/u
307 Date: Sep 2021
308 KernelVersion: v5.14
309 Contact: Mika Westerberg <mika.westerber
310 Description: Returns the current link mode.
311 "usb4", "tbt" and "none".
312
313 What: /sys/bus/thunderbolt/devices/u
314 Date: Sep 2021
315 KernelVersion: v5.14
316 Contact: Rajmohan Mani <rajmohan.mani@in
317 Description: Writing 1 to this attribute pu
318 offline mode. Only allowed whe
319 connected to the port (link at
320 Once the port is in offline mo
321 hotplug events. This is used t
322 on-board retimers. Writing 0 p
323 online mode.
324
325 This attribute is only visible
326 powering on retimers when ther
327
328 What: /sys/bus/thunderbolt/devices/u
329 Date: Sep 2021
330 KernelVersion: v5.14
331 Contact: Rajmohan Mani <rajmohan.mani@in
332 Description: When the USB4 port is in offli
333 attribute forces rescan of the
334 retimers. Each retimer appear
335 the USB4 link was up. These re
336 as if the cable was connected
337 firmware can be done the usual
338
339 What: /sys/bus/thunderbolt/devices/<
340 Date: Oct 2020
341 KernelVersion: v5.9
342 Contact: Mika Westerberg <mika.westerber
343 Description: Retimer device identifier read
344
345 What: /sys/bus/thunderbolt/devices/<
346 Date: Oct 2020
347 KernelVersion: v5.9
348 Contact: Mika Westerberg <mika.westerber
349 Description: When new NVM image is written
350 area (through non_activeX NVMe
351 authentication procedure is st
352 this file. If everything goes
353 restarted with the new NVM fir
354 verification fails an error co
355
356 When read holds status of the
357 operation if an error occurred
358 Format: %x.
359
360 What: /sys/bus/thunderbolt/devices/<
361 Date: Oct 2020
362 KernelVersion: v5.9
363 Contact: Mika Westerberg <mika.westerber
364 Description: Holds retimer NVM version numb
365
366 What: /sys/bus/thunderbolt/devices/<
367 Date: Oct 2020
368 KernelVersion: v5.9
369 Contact: Mika Westerberg <mika.westerber
370 Description: Retimer vendor identifier read
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