From feab398e580b1847b729203573a638cf90d5e7fc Mon Sep 17 00:00:00 2001 From: Kent Yoder Date: Wed, 7 Nov 2012 17:00:45 -0600 Subject: tpm: add documentation for sysfs interfaces Reviewed-by: Peter Huewe Signed-off-by: Kent Yoder --- Documentation/ABI/stable/sysfs-class-tpm | 185 +++++++++++++++++++++++++++++++ 1 file changed, 185 insertions(+) create mode 100644 Documentation/ABI/stable/sysfs-class-tpm (limited to 'Documentation/ABI/stable') diff --git a/Documentation/ABI/stable/sysfs-class-tpm b/Documentation/ABI/stable/sysfs-class-tpm new file mode 100644 index 000000000000..a60b45e2493b --- /dev/null +++ b/Documentation/ABI/stable/sysfs-class-tpm @@ -0,0 +1,185 @@ +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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ossible 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. -- cgit v1.2.1