diff options
authorJoel Sherrill <>2022-09-02 11:25:22 -0500
committerSebastian Huber <>2022-09-05 09:02:06 +0200
commit4f9e9e522f2eee484edffe9d220ae6717367b95b (patch)
parentc-user: Clarify BSP related configuration settings (diff)
c-user/config/face.rst: New file -- add CONFIGURE_POSIX_TIMERS_FACE_BEHAVIOR
Closes #4691.
2 files changed, 77 insertions, 0 deletions
diff --git a/c-user/config/face-technical-standard.rst b/c-user/config/face-technical-standard.rst
new file mode 100644
index 0000000..8772773
--- /dev/null
+++ b/c-user/config/face-technical-standard.rst
@@ -0,0 +1,76 @@
+.. SPDX-License-Identifier: CC-BY-SA-4.0
+.. Copyright (C) 2022 On-Line Applications Research Corporation (OAR)
+.. This file is part of the RTEMS quality process and was automatically
+.. generated. If you find something that needs to be fixed or
+.. worded better please post a report or patch to an RTEMS mailing list
+.. or raise a bug report:
+.. For information on updating and regenerating please refer to the How-To
+.. section in the Software Requirements Engineering chapter of the
+.. RTEMS Software Engineering manual. The manual is provided as a part of
+.. a release. For development sources please refer to the online
+.. documentation at:
+.. Generated from spec:/acfg/if/group-face
+FACE Technical Standard Related Configuration
+This section describes configuration options related to adapting
+RTEMS behavior to be aligned with the FACE Technical Standard.
+The FACE Technical Standard is a product of the FACE Consortium
+which operates under the Open Group. The FACE Consortium was founded
+by avionics organizations to improve the portability of cockpit software
+across various platforms. It addresses technical and business concerns.
+Most important from an RTEMS perspective, the FACE Technical Standard
+defines four POSIX profiles: Security, Safety Base, Safety Extended, and
+the General Purpose Profile. Each has an increasingly larger subset of
+POSIX APIs. In the Security and Safety profiles, ARINC 653 is required.
+It is optional in the General Purpose Profile.
+The RTEMS Project has been tracking alignment with the FACE POSIX profiles
+and they are included in the "RTEMS POSIX 1003.1 Compliance Guide."
+.. Generated from spec:/acfg/if/posix-timer-face-behavior
+.. raw:: latex
+ \clearpage
+.. rubric:: CONSTANT:
+.. rubric:: OPTION TYPE:
+This configuration option is a boolean feature define.
+If this configuration option is undefined, then the described feature is not
+.. rubric:: DESCRIPTION:
+If this configuration option is defined, then POSIX timers may not be created
+to use the :term:`CLOCK_REALTIME`. Per POSIX, this is allowed
+behavior but per the FACE Technical Standard, it is not. Using POSIX timers
+based on CLOCK_REALTIME (e.g., time of day) is unsafe for real-time safety
+systems as setting CLOCK_REALTIME will perturb any active timers.
+If this option is not defined, POSIX timers may be created to use the
+CLOCK_REALTIME in compliance with the POSIX specification.
diff --git a/c-user/config/index.rst b/c-user/config/index.rst
index b0e21a4..fd877b5 100644
--- a/c-user/config/index.rst
+++ b/c-user/config/index.rst
@@ -24,6 +24,7 @@ Configuring a System
+ face-technical-standard