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Based on kernel version 4.7.2. Page generated on 2016-08-22 22:39 EST.

1	What:		/sys/class/tpm/tpmX/ppi/
2	Date:		August 2012
3	Kernel Version:	3.6
4	Contact:	xiaoyan.zhang@intel.com
5	Description:
6			This folder includes the attributes related with PPI (Physical
7			Presence Interface). Only if TPM is supported by BIOS, this
8			folder makes sense. The folder path can be got by command
9			'find /sys/ -name 'pcrs''. For the detail information of PPI,
10			please refer to the PPI specification from
11	
12			http://www.trustedcomputinggroup.org/
13	
14			In Linux 4.2 ppi was moved to the character device directory.
15			A symlink from tpmX/device/ppi to tpmX/ppi to provide backwards
16			compatibility.
17	
18	What:		/sys/class/tpm/tpmX/ppi/version
19	Date:		August 2012
20	Contact:	xiaoyan.zhang@intel.com
21	Description:
22			This attribute shows the version of the PPI supported by the
23			platform.
24			This file is readonly.
25	
26	What:		/sys/class/tpm/tpmX/ppi/request
27	Date:		August 2012
28	Contact:	xiaoyan.zhang@intel.com
29	Description:
30			This attribute shows the request for an operation to be
31			executed in the pre-OS environment. It is the only input from
32			the OS to the pre-OS environment. The request should be an
33			integer value range from 1 to 160, and 0 means no request.
34			This file can be read and written.
35	
36	What:		/sys/class/tpm/tpmX/ppi/response
37	Date:		August 2012
38	Contact:	xiaoyan.zhang@intel.com
39	Description:
40			This attribute shows the response to the most recent operation
41			request it acted upon. The format is "<request> <response num>
42			: <response description>".
43			This file is readonly.
44	
45	What:		/sys/class/tpm/tpmX/ppi/transition_action
46	Date:		August 2012
47	Contact:	xiaoyan.zhang@intel.com
48	Description:
49			This attribute shows the platform-specific action that should
50			take place in order to transition to the BIOS for execution of
51			a requested operation. The format is "<action num>: <action
52			description>".
53			This file is readonly.
54	
55	What:		/sys/class/tpm/tpmX/ppi/tcg_operations
56	Date:		August 2012
57	Contact:	xiaoyan.zhang@intel.com
58	Description:
59			This attribute shows whether it is allowed to request an
60			operation to be executed in the pre-OS environment by the BIOS
61			for the requests defined by TCG, i.e. requests from 1 to 22.
62			The format is "<request> <status num>: <status description>".
63			This attribute is only supported by PPI version 1.2+.
64			This file is readonly.
65	
66	What:		/sys/class/tpm/tpmX/ppi/vs_operations
67	Date:		August 2012
68	Contact:	xiaoyan.zhang@intel.com
69	Description:
70			This attribute shows whether it is allowed to request an
71			operation to be executed in the pre-OS environment by the BIOS
72			for the verdor specific requests, i.e. requests from 128 to
73			255. The format is same with tcg_operations. This attribute
74			is also only supported by PPI version 1.2+.
75			This file is readonly.
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