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authorKent Yoder <key@linux.vnet.ibm.com>2012-11-08 03:00:45 +0400
committerKent Yoder <key@linux.vnet.ibm.com>2013-02-05 19:38:21 +0400
commitfeab398e580b1847b729203573a638cf90d5e7fc (patch)
tree95d951d8440ad3e4db46977088ce041d7a8ac31d /Documentation/ABI/stable/sysfs-class-tpm
parent0d2a1b2d03dfd5ee79e7ebc59635690c8f08810f (diff)
downloadlinux-feab398e580b1847b729203573a638cf90d5e7fc.tar.xz
tpm: add documentation for sysfs interfaces
Reviewed-by: Peter Huewe <peter.huewe@infineon.com> Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>
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+What: /sys/class/misc/tpmX/device/
+Date: April 2005
+KernelVersion: 2.6.12
+Contact: tpmdd-devel@lists.sf.net
+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: tpmdd-devel@lists.sf.net
+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: tpmdd-devel@lists.sf.net
+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: tpmdd-devel@lists.sf.net
+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: tpmdd-devel@lists.sf.net
+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: tpmdd-devel@lists.sf.net
+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: tpmdd-devel@lists.sf.net
+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: tpmdd-devel@lists.sf.net
+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: tpmdd-devel@lists.sf.net
+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: tpmdd-devel@lists.sf.net
+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: tpmdd-devel@lists.sf.net
+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.