forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
tpm: add documentation for sysfs interfaces
Reviewed-by: Peter Huewe <[email protected]> Signed-off-by: Kent Yoder <[email protected]>
- Loading branch information
Kent Yoder
committed
Feb 5, 2013
1 parent
0d2a1b2
commit feab398
Showing
1 changed file
with
185 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,185 @@ | ||
What: /sys/class/misc/tpmX/device/ | ||
Date: April 2005 | ||
KernelVersion: 2.6.12 | ||
Contact: [email protected] | ||
Description: The device/ directory under a specific TPM instance exposes | ||
the properties of that TPM chip | ||
|
||
|
||
What: /sys/class/misc/tpmX/device/active | ||
Date: April 2006 | ||
KernelVersion: 2.6.17 | ||
Contact: [email protected] | ||
Description: The "active" property prints a '1' if the TPM chip is accepting | ||
commands. An inactive TPM chip still contains all the state of | ||
an active chip (Storage Root Key, NVRAM, etc), and can be | ||
visible to the OS, but will only accept a restricted set of | ||
commands. See the TPM Main Specification part 2, Structures, | ||
section 17 for more information on which commands are | ||
available. | ||
|
||
What: /sys/class/misc/tpmX/device/cancel | ||
Date: June 2005 | ||
KernelVersion: 2.6.13 | ||
Contact: [email protected] | ||
Description: The "cancel" property allows you to cancel the currently | ||
pending TPM command. Writing any value to cancel will call the | ||
TPM vendor specific cancel operation. | ||
|
||
What: /sys/class/misc/tpmX/device/caps | ||
Date: April 2005 | ||
KernelVersion: 2.6.12 | ||
Contact: [email protected] | ||
Description: The "caps" property contains TPM manufacturer and version info. | ||
|
||
Example output: | ||
|
||
Manufacturer: 0x53544d20 | ||
TCG version: 1.2 | ||
Firmware version: 8.16 | ||
|
||
Manufacturer is a hex dump of the 4 byte manufacturer info | ||
space in a TPM. TCG version shows the TCG TPM spec level that | ||
the chip supports. Firmware version is that of the chip and | ||
is manufacturer specific. | ||
|
||
What: /sys/class/misc/tpmX/device/durations | ||
Date: March 2011 | ||
KernelVersion: 3.1 | ||
Contact: [email protected] | ||
Description: The "durations" property shows the 3 vendor-specific values | ||
used to wait for a short, medium and long TPM command. All | ||
TPM commands are categorized as short, medium or long in | ||
execution time, so that the driver doesn't have to wait | ||
any longer than necessary before starting to poll for a | ||
result. | ||
|
||
Example output: | ||
|
||
3015000 4508000 180995000 [original] | ||
|
||
Here the short, medium and long durations are displayed in | ||
usecs. "[original]" indicates that the values are displayed | ||
unmodified from when they were queried from the chip. | ||
Durations can be modified in the case where a buggy chip | ||
reports them in msec instead of usec and they need to be | ||
scaled to be displayed in usecs. In this case "[adjusted]" | ||
will be displayed in place of "[original]". | ||
|
||
What: /sys/class/misc/tpmX/device/enabled | ||
Date: April 2006 | ||
KernelVersion: 2.6.17 | ||
Contact: [email protected] | ||
Description: The "enabled" property prints a '1' if the TPM chip is enabled, | ||
meaning that it should be visible to the OS. This property | ||
may be visible but produce a '0' after some operation that | ||
disables the TPM. | ||
|
||
What: /sys/class/misc/tpmX/device/owned | ||
Date: April 2006 | ||
KernelVersion: 2.6.17 | ||
Contact: [email protected] | ||
Description: The "owned" property produces a '1' if the TPM_TakeOwnership | ||
ordinal has been executed successfully in the chip. A '0' | ||
indicates that ownership hasn't been taken. | ||
|
||
What: /sys/class/misc/tpmX/device/pcrs | ||
Date: April 2005 | ||
KernelVersion: 2.6.12 | ||
Contact: [email protected] | ||
Description: The "pcrs" property will dump the current value of all Platform | ||
Configuration Registers in the TPM. Note that since these | ||
values may be constantly changing, the output is only valid | ||
for a snapshot in time. | ||
|
||
Example output: | ||
|
||
PCR-00: 3A 3F 78 0F 11 A4 B4 99 69 FC AA 80 CD 6E 39 57 C3 3B 22 75 | ||
PCR-01: 3A 3F 78 0F 11 A4 B4 99 69 FC AA 80 CD 6E 39 57 C3 3B 22 75 | ||
PCR-02: 3A 3F 78 0F 11 A4 B4 99 69 FC AA 80 CD 6E 39 57 C3 3B 22 75 | ||
PCR-03: 3A 3F 78 0F 11 A4 B4 99 69 FC AA 80 CD 6E 39 57 C3 3B 22 75 | ||
PCR-04: 3A 3F 78 0F 11 A4 B4 99 69 FC AA 80 CD 6E 39 57 C3 3B 22 75 | ||
... | ||
|
||
The number of PCRs and hex bytes needed to represent a PCR | ||
value will vary depending on TPM chip version. For TPM 1.1 and | ||
1.2 chips, PCRs represent SHA-1 hashes, which are 20 bytes | ||
long. Use the "caps" property to determine TPM version. | ||
|
||
What: /sys/class/misc/tpmX/device/pubek | ||
Date: April 2005 | ||
KernelVersion: 2.6.12 | ||
Contact: [email protected] | ||
Description: The "pubek" property will return the TPM's public endorsement | ||
key if possible. If the TPM has had ownership established and | ||
is version 1.2, the pubek will not be available without the | ||
owner's authorization. Since the TPM driver doesn't store any | ||
secrets, it can't authorize its own request for the pubek, | ||
making it unaccessible. The public endorsement key is gener- | ||
ated at TPM menufacture time and exists for the life of the | ||
chip. | ||
|
||
Example output: | ||
|
||
Algorithm: 00 00 00 01 | ||
Encscheme: 00 03 | ||
Sigscheme: 00 01 | ||
Parameters: 00 00 08 00 00 00 00 02 00 00 00 00 | ||
Modulus length: 256 | ||
Modulus: | ||
B4 76 41 82 C9 20 2C 10 18 40 BC 8B E5 44 4C 6C | ||
3A B2 92 0C A4 9B 2A 83 EB 5C 12 85 04 48 A0 B6 | ||
1E E4 81 84 CE B2 F2 45 1C F0 85 99 61 02 4D EB | ||
86 C4 F7 F3 29 60 52 93 6B B2 E5 AB 8B A9 09 E3 | ||
D7 0E 7D CA 41 BF 43 07 65 86 3C 8C 13 7A D0 8B | ||
82 5E 96 0B F8 1F 5F 34 06 DA A2 52 C1 A9 D5 26 | ||
0F F4 04 4B D9 3F 2D F2 AC 2F 74 64 1F 8B CD 3E | ||
1E 30 38 6C 70 63 69 AB E2 50 DF 49 05 2E E1 8D | ||
6F 78 44 DA 57 43 69 EE 76 6C 38 8A E9 8E A3 F0 | ||
A7 1F 3C A8 D0 12 15 3E CA 0E BD FA 24 CD 33 C6 | ||
47 AE A4 18 83 8E 22 39 75 93 86 E6 FD 66 48 B6 | ||
10 AD 94 14 65 F9 6A 17 78 BD 16 53 84 30 BF 70 | ||
E0 DC 65 FD 3C C6 B0 1E BF B9 C1 B5 6C EF B1 3A | ||
F8 28 05 83 62 26 11 DC B4 6B 5A 97 FF 32 26 B6 | ||
F7 02 71 CF 15 AE 16 DD D1 C1 8E A8 CF 9B 50 7B | ||
C3 91 FF 44 1E CF 7C 39 FE 17 77 21 20 BD CE 9B | ||
|
||
Possible values: | ||
|
||
Algorithm: TPM_ALG_RSA (1) | ||
Encscheme: TPM_ES_RSAESPKCSv15 (2) | ||
TPM_ES_RSAESOAEP_SHA1_MGF1 (3) | ||
Sigscheme: TPM_SS_NONE (1) | ||
Parameters, a byte string of 3 u32 values: | ||
Key Length (bits): 00 00 08 00 (2048) | ||
Num primes: 00 00 00 02 (2) | ||
Exponent Size: 00 00 00 00 (0 means the | ||
default exp) | ||
Modulus Length: 256 (bytes) | ||
Modulus: The 256 byte Endorsement Key modulus | ||
|
||
What: /sys/class/misc/tpmX/device/temp_deactivated | ||
Date: April 2006 | ||
KernelVersion: 2.6.17 | ||
Contact: [email protected] | ||
Description: The "temp_deactivated" property returns a '1' if the chip has | ||
been temporarily dectivated, usually until the next power | ||
cycle. Whether a warm boot (reboot) will clear a TPM chip | ||
from a temp_deactivated state is platform specific. | ||
|
||
What: /sys/class/misc/tpmX/device/timeouts | ||
Date: March 2011 | ||
KernelVersion: 3.1 | ||
Contact: [email protected] | ||
Description: The "timeouts" property shows the 4 vendor-specific values | ||
for the TPM's interface spec timeouts. The use of these | ||
timeouts is defined by the TPM interface spec that the chip | ||
conforms to. | ||
|
||
Example output: | ||
|
||
750000 750000 750000 750000 [original] | ||
|
||
The four timeout values are shown in usecs, with a trailing | ||
"[original]" or "[adjusted]" depending on whether the values | ||
were scaled by the driver to be reported in usec from msecs. |