1 What: /sys/class/tpm/tpmX/ppi/ 1 What: /sys/class/tpm/tpmX/ppi/
2 Date: August 2012 2 Date: August 2012
3 KernelVersion: 3.6 !! 3 Kernel Version: 3.6
4 Contact: xiaoyan.zhang@intel.com 4 Contact: xiaoyan.zhang@intel.com
5 Description: 5 Description:
6 This folder includes the attri 6 This folder includes the attributes related with PPI (Physical
7 Presence Interface). Only if T 7 Presence Interface). Only if TPM is supported by BIOS, this
8 folder makes sense. The folder 8 folder makes sense. The folder path can be got by command
9 'find /sys/ -name 'pcrs''. For 9 'find /sys/ -name 'pcrs''. For the detail information of PPI,
10 please refer to the PPI specif 10 please refer to the PPI specification from
11 11
12 http://www.trustedcomputinggro 12 http://www.trustedcomputinggroup.org/
13 13
14 In Linux 4.2 ppi was moved to 14 In Linux 4.2 ppi was moved to the character device directory.
15 A symlink from tpmX/device/ppi 15 A symlink from tpmX/device/ppi to tpmX/ppi to provide backwards
16 compatibility. 16 compatibility.
17 17
18 What: /sys/class/tpm/tpmX/ppi/versio 18 What: /sys/class/tpm/tpmX/ppi/version
19 Date: August 2012 19 Date: August 2012
20 Contact: xiaoyan.zhang@intel.com 20 Contact: xiaoyan.zhang@intel.com
21 Description: 21 Description:
22 This attribute shows the versi 22 This attribute shows the version of the PPI supported by the
23 platform. 23 platform.
24 This file is readonly. 24 This file is readonly.
25 25
26 What: /sys/class/tpm/tpmX/ppi/reques 26 What: /sys/class/tpm/tpmX/ppi/request
27 Date: August 2012 27 Date: August 2012
28 Contact: xiaoyan.zhang@intel.com 28 Contact: xiaoyan.zhang@intel.com
29 Description: 29 Description:
30 This attribute shows the reque 30 This attribute shows the request for an operation to be
31 executed in the pre-OS environ 31 executed in the pre-OS environment. It is the only input from
32 the OS to the pre-OS environme 32 the OS to the pre-OS environment. The request should be an
33 integer value range from 1 to 33 integer value range from 1 to 160, and 0 means no request.
34 This file can be read and writ 34 This file can be read and written.
35 35
36 What: /sys/class/tpm/tpmX/ppi/respon 36 What: /sys/class/tpm/tpmX/ppi/response
37 Date: August 2012 37 Date: August 2012
38 Contact: xiaoyan.zhang@intel.com 38 Contact: xiaoyan.zhang@intel.com
39 Description: 39 Description:
40 This attribute shows the respo 40 This attribute shows the response to the most recent operation
41 request it acted upon. The for 41 request it acted upon. The format is "<request> <response num>
42 : <response description>". 42 : <response description>".
43 This file is readonly. 43 This file is readonly.
44 44
45 What: /sys/class/tpm/tpmX/ppi/transi 45 What: /sys/class/tpm/tpmX/ppi/transition_action
46 Date: August 2012 46 Date: August 2012
47 Contact: xiaoyan.zhang@intel.com 47 Contact: xiaoyan.zhang@intel.com
48 Description: 48 Description:
49 This attribute shows the platf 49 This attribute shows the platform-specific action that should
50 take place in order to transit 50 take place in order to transition to the BIOS for execution of
51 a requested operation. The for 51 a requested operation. The format is "<action num>: <action
52 description>". 52 description>".
53 This file is readonly. 53 This file is readonly.
54 54
55 What: /sys/class/tpm/tpmX/ppi/tcg_op 55 What: /sys/class/tpm/tpmX/ppi/tcg_operations
56 Date: August 2012 56 Date: August 2012
57 Contact: xiaoyan.zhang@intel.com 57 Contact: xiaoyan.zhang@intel.com
58 Description: 58 Description:
59 This attribute shows whether i 59 This attribute shows whether it is allowed to request an
60 operation to be executed in th 60 operation to be executed in the pre-OS environment by the BIOS
61 for the requests defined by TC 61 for the requests defined by TCG, i.e. requests from 1 to 22.
62 The format is "<request> <stat 62 The format is "<request> <status num>: <status description>".
63 This attribute is only support 63 This attribute is only supported by PPI version 1.2+.
64 This file is readonly. 64 This file is readonly.
65 65
66 What: /sys/class/tpm/tpmX/ppi/vs_ope 66 What: /sys/class/tpm/tpmX/ppi/vs_operations
67 Date: August 2012 67 Date: August 2012
68 Contact: xiaoyan.zhang@intel.com 68 Contact: xiaoyan.zhang@intel.com
69 Description: 69 Description:
70 This attribute shows whether i 70 This attribute shows whether it is allowed to request an
71 operation to be executed in th 71 operation to be executed in the pre-OS environment by the BIOS
72 for the verdor specific reques 72 for the verdor specific requests, i.e. requests from 128 to
73 255. The format is same with t 73 255. The format is same with tcg_operations. This attribute
74 is also only supported by PPI 74 is also only supported by PPI version 1.2+.
75 This file is readonly. 75 This file is readonly.
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