1*4882a593SmuzhiyunWhat: /sys/class/tpm/tpmX/ppi/ 2*4882a593SmuzhiyunDate: August 2012 3*4882a593SmuzhiyunKernelVersion: 3.6 4*4882a593SmuzhiyunContact: xiaoyan.zhang@intel.com 5*4882a593SmuzhiyunDescription: 6*4882a593Smuzhiyun This folder includes the attributes related with PPI (Physical 7*4882a593Smuzhiyun Presence Interface). Only if TPM is supported by BIOS, this 8*4882a593Smuzhiyun folder makes sense. The folder path can be got by command 9*4882a593Smuzhiyun 'find /sys/ -name 'pcrs''. For the detail information of PPI, 10*4882a593Smuzhiyun please refer to the PPI specification from 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun http://www.trustedcomputinggroup.org/ 13*4882a593Smuzhiyun 14*4882a593Smuzhiyun In Linux 4.2 ppi was moved to the character device directory. 15*4882a593Smuzhiyun A symlink from tpmX/device/ppi to tpmX/ppi to provide backwards 16*4882a593Smuzhiyun compatibility. 17*4882a593Smuzhiyun 18*4882a593SmuzhiyunWhat: /sys/class/tpm/tpmX/ppi/version 19*4882a593SmuzhiyunDate: August 2012 20*4882a593SmuzhiyunContact: xiaoyan.zhang@intel.com 21*4882a593SmuzhiyunDescription: 22*4882a593Smuzhiyun This attribute shows the version of the PPI supported by the 23*4882a593Smuzhiyun platform. 24*4882a593Smuzhiyun This file is readonly. 25*4882a593Smuzhiyun 26*4882a593SmuzhiyunWhat: /sys/class/tpm/tpmX/ppi/request 27*4882a593SmuzhiyunDate: August 2012 28*4882a593SmuzhiyunContact: xiaoyan.zhang@intel.com 29*4882a593SmuzhiyunDescription: 30*4882a593Smuzhiyun This attribute shows the request for an operation to be 31*4882a593Smuzhiyun executed in the pre-OS environment. It is the only input from 32*4882a593Smuzhiyun the OS to the pre-OS environment. The request should be an 33*4882a593Smuzhiyun integer value range from 1 to 160, and 0 means no request. 34*4882a593Smuzhiyun This file can be read and written. 35*4882a593Smuzhiyun 36*4882a593SmuzhiyunWhat: /sys/class/tpm/tpmX/ppi/response 37*4882a593SmuzhiyunDate: August 2012 38*4882a593SmuzhiyunContact: xiaoyan.zhang@intel.com 39*4882a593SmuzhiyunDescription: 40*4882a593Smuzhiyun This attribute shows the response to the most recent operation 41*4882a593Smuzhiyun request it acted upon. The format is "<request> <response num> 42*4882a593Smuzhiyun : <response description>". 43*4882a593Smuzhiyun This file is readonly. 44*4882a593Smuzhiyun 45*4882a593SmuzhiyunWhat: /sys/class/tpm/tpmX/ppi/transition_action 46*4882a593SmuzhiyunDate: August 2012 47*4882a593SmuzhiyunContact: xiaoyan.zhang@intel.com 48*4882a593SmuzhiyunDescription: 49*4882a593Smuzhiyun This attribute shows the platform-specific action that should 50*4882a593Smuzhiyun take place in order to transition to the BIOS for execution of 51*4882a593Smuzhiyun a requested operation. The format is "<action num>: <action 52*4882a593Smuzhiyun description>". 53*4882a593Smuzhiyun This file is readonly. 54*4882a593Smuzhiyun 55*4882a593SmuzhiyunWhat: /sys/class/tpm/tpmX/ppi/tcg_operations 56*4882a593SmuzhiyunDate: August 2012 57*4882a593SmuzhiyunContact: xiaoyan.zhang@intel.com 58*4882a593SmuzhiyunDescription: 59*4882a593Smuzhiyun This attribute shows whether it is allowed to request an 60*4882a593Smuzhiyun operation to be executed in the pre-OS environment by the BIOS 61*4882a593Smuzhiyun for the requests defined by TCG, i.e. requests from 1 to 22. 62*4882a593Smuzhiyun The format is "<request> <status num>: <status description>". 63*4882a593Smuzhiyun This attribute is only supported by PPI version 1.2+. 64*4882a593Smuzhiyun This file is readonly. 65*4882a593Smuzhiyun 66*4882a593SmuzhiyunWhat: /sys/class/tpm/tpmX/ppi/vs_operations 67*4882a593SmuzhiyunDate: August 2012 68*4882a593SmuzhiyunContact: xiaoyan.zhang@intel.com 69*4882a593SmuzhiyunDescription: 70*4882a593Smuzhiyun This attribute shows whether it is allowed to request an 71*4882a593Smuzhiyun operation to be executed in the pre-OS environment by the BIOS 72*4882a593Smuzhiyun for the verdor specific requests, i.e. requests from 128 to 73*4882a593Smuzhiyun 255. The format is same with tcg_operations. This attribute 74*4882a593Smuzhiyun is also only supported by PPI version 1.2+. 75*4882a593Smuzhiyun This file is readonly. 76