Developer Guide

  • 10/27/2020
  • Public Content
Contents

Secure Time

This page provides an overview of the Secure Time feature. For detailed instructions and guidelines on how to implement it, see
Secure Time Guidelines
.
Intel® DAL supports the getting and setting of a secure time using the platform Protected Run-Time Clock (PRTC). There is no globally available initial time. Therefore, trusted applications still need to get the initial secure time from some trusted source, such as Sigma.
Note:
For security reasons, each set trusted application time is independent of all other trusted applications and their set times.
Applications can use this feature to create their own notion of time. The feature can be used to always know the current time.
The
FEATURE_SET_STORAGE_SECURE_TIME
bit of the return value of the API indicates whether the secure time feature is supported or not. For example, Intel Atom® SoC code name Broxton coinless platforms do not support it. 
Warning:
The Calendar may reset occasionally on coinless platforms (If there is no coin battery, i.e.,
com.intel.util.PlatformInfo.isCoinBatteryPresent()
returns
False
, the platform is designed such that it may lose Protected Real Time Clock (PRTC) power more than 10 times throughout the normal life cycle of the product and thus has no persistent time).
Supported from API level 1

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804