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Review changes from Chris Mayfield.

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Chris Johns
2016-04-01 12:20:13 +11:00
committed by Amar Takhar
parent aae09e24ae
commit ea0777e4ee
3 changed files with 63 additions and 57 deletions
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user/overview/index.rst
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@@ -6,8 +6,8 @@ Overview
Welcome to the :ref:term:`RTEMS` User Manual.
This document covers all the topic required as a user of RTEMS to use the RTEMS
operating system.
This document covers all the topics required as a user of RTEMS to use the
RTEMS operating system.
RTEMS, Real-Time Executive for Multiprocessor Systems, is a real-time executive
(kernel) which provides a high performance environment for embedded
@@ -15,7 +15,7 @@ applications including the following features:
.. sidebar:: Developers
Developers should look at the :r:url:`devel` for technical information the
Developers should look at the :r:url:`devel` for technical information. The
design and development of RTEMS is located there.
- multitasking capabilities
@@ -61,9 +61,9 @@ interdependent, asynchronous or cyclical event streams.
Deadlines can be further characterized as either hard or soft based upon the
value of the results when produced after the deadline has passed. A deadline
is hard if the results have no value or if their use will result in a
catastrophic event. In contrast, results which are produced after a soft
deadline may have some value.
is hard if the results have no value after the deadline has passed, or a
catastophic event results from their intended use if not completed on time. In
contrast, results produced after a soft deadline may still have some value.
Another distinguishing requirement of real-time application systems is the
ability to coordinate or manage a large number of concurrent activities. Since
@@ -84,7 +84,7 @@ complicate each and every characteristic of a real-time system.
Real-time Executive
===================
Fortunately, real-time operating systems or real-time executives serve as a
Fortunately, real-time operating systems, or real-time executives, serve as a
cornerstone on which to build the application system. A real-time multitasking
executive allows an application to be cast into a set of logical, autonomous
processes or tasks which become quite manageable. Each task is internally
@@ -99,19 +99,19 @@ CPU instruction set to support efficient multitasking. By causing tasks to
travel through well-defined state transitions, system calls permit an
application to demand-switch between tasks in response to real-time events.
By proper grouping of responses to stimuli into separate tasks, a system can
now asynchronously switch between independent streams of execution, directly
responding to external stimuli as they occur. This allows the system design to
meet critical performance specifications which are typically measured by
guaranteed response time and transaction throughput. The multiprocessor
extensions of RTEMS provide the features necessary to manage the extra
requirements introduced by a system distributed across several processors. It
removes the physical barriers of processor boundaries from the world of the
system designer, enabling more critical aspects of the system to receive the
required attention. Such a system, based on an efficient real-time,
multiprocessor executive, is a more realistic model of the outside world or
environment for which it is designed. As a result, the system will always be
more logical, efficient, and reliable.
By properly grouping stimuli responses into separate tasks a system can now
asynchronously switch between independent streams of execution. This allows the
system to directly respond to external stimuli as they occur, as well as meet
critical performance specifications that are typically measured by guaranteed
response time and transaction throughput. The multiprocessor extensions of
RTEMS provide the features necessary to manage the extra requirements
introduced by a system distributed across several processors. It removes the
physical barriers of processor boundaries from the world of the system
designer, enabling more critical aspects of the system to receive the required
attention. Such a system, based on an efficient real-time, multiprocessor
executive, is a more realistic model of the outside world or environment for
which it is designed. As a result, the system will always be more logical,
efficient, and reliable.
By using the directives provided by RTEMS, the real-time applications developer
is freed from the problem of controlling and synchronizing multiple tasks and
@@ -124,14 +124,14 @@ sophisticated real-time applications is significantly reduced.
Open Source
===========
RTEMS is an open source operating and an open source project. As a user you
have access to all the source code and we encourage you to work with the source
code and to integrate the processes used to build tools, the kernel and any 3rd
party libraries into your project's configuration management processes. The
RTEMS project is always improving the way it develivers the kernel to you and
so your feedback is important.
RTEMS is an open source operating system and an open source project. As a user,
you have access to all the source code. We encourage you to work with the
source code and integrate the provided processes used to build tools, the
kernel and any 3rd party libraries into your project's configuration management
processes. The RTEMS project is always improving the way it develivers the
kernel to you and so your feedback is important.
What we used in the RTEMS project to develop and maintain RTEMS does not
dictate what you use to develop and maintain your project. You can and should
dictate what you use to develop and maintain your project. You can, and should,
select the work-flow that best suites the demands of your project and what you
are delivering.