sysfs-driver-ppi 2.6 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475
  1. What: /sys/class/tpm/tpmX/ppi/
  2. Date: August 2012
  3. KernelVersion: 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. http://www.trustedcomputinggroup.org/
  12. In Linux 4.2 ppi was moved to the character device directory.
  13. A symlink from tpmX/device/ppi to tpmX/ppi to provide backwards
  14. compatibility.
  15. What: /sys/class/tpm/tpmX/ppi/version
  16. Date: August 2012
  17. Contact: xiaoyan.zhang@intel.com
  18. Description:
  19. This attribute shows the version of the PPI supported by the
  20. platform.
  21. This file is readonly.
  22. What: /sys/class/tpm/tpmX/ppi/request
  23. Date: August 2012
  24. Contact: xiaoyan.zhang@intel.com
  25. Description:
  26. This attribute shows the request for an operation to be
  27. executed in the pre-OS environment. It is the only input from
  28. the OS to the pre-OS environment. The request should be an
  29. integer value range from 1 to 160, and 0 means no request.
  30. This file can be read and written.
  31. What: /sys/class/tpm/tpmX/ppi/response
  32. Date: August 2012
  33. Contact: xiaoyan.zhang@intel.com
  34. Description:
  35. This attribute shows the response to the most recent operation
  36. request it acted upon. The format is "<request> <response num>
  37. : <response description>".
  38. This file is readonly.
  39. What: /sys/class/tpm/tpmX/ppi/transition_action
  40. Date: August 2012
  41. Contact: xiaoyan.zhang@intel.com
  42. Description:
  43. This attribute shows the platform-specific action that should
  44. take place in order to transition to the BIOS for execution of
  45. a requested operation. The format is "<action num>: <action
  46. description>".
  47. This file is readonly.
  48. What: /sys/class/tpm/tpmX/ppi/tcg_operations
  49. Date: August 2012
  50. Contact: xiaoyan.zhang@intel.com
  51. Description:
  52. This attribute shows whether it is allowed to request an
  53. operation to be executed in the pre-OS environment by the BIOS
  54. for the requests defined by TCG, i.e. requests from 1 to 22.
  55. The format is "<request> <status num>: <status description>".
  56. This attribute is only supported by PPI version 1.2+.
  57. This file is readonly.
  58. What: /sys/class/tpm/tpmX/ppi/vs_operations
  59. Date: August 2012
  60. Contact: xiaoyan.zhang@intel.com
  61. Description:
  62. This attribute shows whether it is allowed to request an
  63. operation to be executed in the pre-OS environment by the BIOS
  64. for the verdor specific requests, i.e. requests from 128 to
  65. 255. The format is same with tcg_operations. This attribute
  66. is also only supported by PPI version 1.2+.
  67. This file is readonly.