| What: /sys/devices/pnp0/<bus-num>/ppi/ | |
| Date: August 2012 | |
| Kernel Version: 3.6 | |
| Contact: xiaoyan.zhang@intel.com | |
| Description: | |
| This folder includes the attributes related with PPI (Physical | |
| Presence Interface). Only if TPM is supported by BIOS, this | |
| folder makes sense. The folder path can be got by command | |
| 'find /sys/ -name 'pcrs''. For the detail information of PPI, | |
| please refer to the PPI specification from | |
| http://www.trustedcomputinggroup.org/ | |
| What: /sys/devices/pnp0/<bus-num>/ppi/version | |
| Date: August 2012 | |
| Contact: xiaoyan.zhang@intel.com | |
| Description: | |
| This attribute shows the version of the PPI supported by the | |
| platform. | |
| This file is readonly. | |
| What: /sys/devices/pnp0/<bus-num>/ppi/request | |
| Date: August 2012 | |
| Contact: xiaoyan.zhang@intel.com | |
| Description: | |
| This attribute shows the request for an operation to be | |
| executed in the pre-OS environment. It is the only input from | |
| the OS to the pre-OS environment. The request should be an | |
| integer value range from 1 to 160, and 0 means no request. | |
| This file can be read and written. | |
| What: /sys/devices/pnp0/00:<bus-num>/ppi/response | |
| Date: August 2012 | |
| Contact: xiaoyan.zhang@intel.com | |
| Description: | |
| This attribute shows the response to the most recent operation | |
| request it acted upon. The format is "<request> <response num> | |
| : <response description>". | |
| This file is readonly. | |
| What: /sys/devices/pnp0/<bus-num>/ppi/transition_action | |
| Date: August 2012 | |
| Contact: xiaoyan.zhang@intel.com | |
| Description: | |
| This attribute shows the platform-specific action that should | |
| take place in order to transition to the BIOS for execution of | |
| a requested operation. The format is "<action num>: <action | |
| description>". | |
| This file is readonly. | |
| What: /sys/devices/pnp0/<bus-num>/ppi/tcg_operations | |
| Date: August 2012 | |
| Contact: xiaoyan.zhang@intel.com | |
| Description: | |
| This attribute shows whether it is allowed to request an | |
| operation to be executed in the pre-OS environment by the BIOS | |
| for the requests defined by TCG, i.e. requests from 1 to 22. | |
| The format is "<request> <status num>: <status description>". | |
| This attribute is only supported by PPI version 1.2+. | |
| This file is readonly. | |
| What: /sys/devices/pnp0/<bus-num>/ppi/vs_operations | |
| Date: August 2012 | |
| Contact: xiaoyan.zhang@intel.com | |
| Description: | |
| This attribute shows whether it is allowed to request an | |
| operation to be executed in the pre-OS environment by the BIOS | |
| for the verdor specific requests, i.e. requests from 128 to | |
| 255. The format is same with tcg_operations. This attribute | |
| is also only supported by PPI version 1.2+. | |
| This file is readonly. |