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authorJoel Sherrill <joel.sherrill@OARcorp.com>2008-04-16 18:30:16 +0000
committerJoel Sherrill <joel.sherrill@OARcorp.com>2008-04-16 18:30:16 +0000
commit211cafba7fffec27986d8e5e9b3826af94e4e383 (patch)
tree125c1cfc35401728d83ca721816d902a0f4a7f85 /doc/user/overview.t
parent58b9db58773cfdc43c38a4399b99309ab23b78b6 (diff)
downloadrtems-211cafba7fffec27986d8e5e9b3826af94e4e383.tar.bz2
2008-04-16 Joel Sherrill <joel.sherrill@OARcorp.com>
* user/bsp.t, user/conf.t, user/init.t, user/intr.t, user/overview.t, user/timer.t: Correct default values. Make it clear that confdefs.h calculates the memory required for you.
Diffstat (limited to '')
-rw-r--r--doc/user/overview.t43
1 files changed, 15 insertions, 28 deletions
diff --git a/doc/user/overview.t b/doc/user/overview.t
index 817d0dc552..d5e0a05506 100644
--- a/doc/user/overview.t
+++ b/doc/user/overview.t
@@ -1,5 +1,5 @@
@c
-@c COPYRIGHT (c) 1988-2002.
+@c COPYRIGHT (c) 1988-2008.
@c On-Line Applications Research Corporation (OAR).
@c All rights reserved.
@c
@@ -329,33 +329,20 @@ microprocessor architecture.
@section Memory Requirements
Since memory is a critical resource in many real-time
-embedded systems, RTEMS was specifically designed to allow
-unused managers to be excluded from the run-time environment.
-This allows the application designer the flexibility to tailor
-RTEMS to most efficiently meet system requirements while still
-satisfying even the most stringent memory constraints. As a
-result, the size of the RTEMS executive is application
-dependent. A worksheet is provided in the Memory Requirements
-chapter of the Applications Supplement document for a specific
-target processor. The worksheet is used to calculate the memory
-requirements of a custom RTEMS run-time environment. The
-following managers may be optionally excluded:
-
-@itemize @bullet
-@item clock
-@item timer
-@item semaphore
-@item message
-@item event
-@item signal
-@item partition
-@item region
-@item dual ported memory
-@item I/O
-@item rate monotonic
-@item fatal error
-@item multiprocessing
-@end itemize
+embedded systems, RTEMS was specifically designed to automatically
+leave out all services that are not required from the run-time
+environment. Features such as networking, various fileystems,
+and many other features are completely optionsl. This allows
+the application designer the flexibility to tailor RTEMS to most
+efficiently meet system requirements while still satisfying even
+the most stringent memory constraints. As a result, the size
+of the RTEMS executive is application dependent.
+
+RTEMS requires RAM to manage each instance of an RTEMS object
+that is created. Thus the more RTEMS objects an application
+needs, the more memory that must be reserved. See
+@ref{Configuring a System Determining Memory Requirements} for
+more details.
RTEMS utilizes memory for both code and data space.
Although RTEMS' data space must be in RAM, its code space can be