| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | What: /sys/class/tpm/tpmX/ppi/ |
| 2 | Date: August 2012 |
| David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 3 | KernelVersion: 3.6 |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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. |
