[PATCH 02/20] c-user: Move "General System Configuration"
Sebastian Huber
sebastian.huber at embedded-brains.de
Mon Mar 9 09:02:45 UTC 2020
Update #3836.
---
c-user/config/general-config.rst | 639 +++++++++++++++++++++++++++++++++++++++
c-user/config/index.rst | 637 +-------------------------------------
2 files changed, 640 insertions(+), 636 deletions(-)
create mode 100644 c-user/config/general-config.rst
diff --git a/c-user/config/general-config.rst b/c-user/config/general-config.rst
new file mode 100644
index 0000000..f6d7531
--- /dev/null
+++ b/c-user/config/general-config.rst
@@ -0,0 +1,639 @@
+.. SPDX-License-Identifier: CC-BY-SA-4.0
+
+.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
+
+General System Configuration
+============================
+
+This section defines the general system configuration options supported by
+``<rtems/confdefs.h>``.
+
+.. index:: CONFIGURE_DIRTY_MEMORY
+
+.. _CONFIGURE_DIRTY_MEMORY:
+
+CONFIGURE_DIRTY_MEMORY
+----------------------
+
+CONSTANT:
+ ``CONFIGURE_DIRTY_MEMORY``
+
+DATA TYPE:
+ Boolean feature macro.
+
+RANGE:
+ Defined or undefined.
+
+DEFAULT VALUE:
+ By default, the memory used by the RTEMS Workspace and the C Program Heap
+ is uninitialized memory.
+
+DESCRIPTION:
+ This macro indicates whether RTEMS should dirty the memory used by the
+ RTEMS Workspace and the C Program Heap as part of its initialization. If
+ defined, the memory areas are dirtied with a ``0xCF`` byte pattern.
+ Otherwise, they are not.
+
+NOTES:
+ Dirtying memory can add significantly to system boot time. It may assist in
+ finding code that incorrectly assumes the contents of free memory areas is
+ cleared to zero during system initialization. In case
+ :ref:`CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY` is also defined, then the
+ memory is first dirtied and then zeroed.
+
+.. index:: CONFIGURE_EXTRA_TASK_STACKS
+.. index:: memory for task tasks
+
+.. _CONFIGURE_EXTRA_TASK_STACKS:
+
+CONFIGURE_EXTRA_TASK_STACKS
+---------------------------
+
+CONSTANT:
+ ``CONFIGURE_EXTRA_TASK_STACKS``
+
+DATA TYPE:
+ Unsigned integer (``size_t``).
+
+RANGE:
+ Undefined or positive.
+
+DEFAULT VALUE:
+ The default value is 0.
+
+DESCRIPTION:
+ This configuration parameter is set to the number of bytes the applications
+ wishes to add to the task stack requirements calculated by
+ ``<rtems/confdefs.h>``.
+
+NOTES:
+ This parameter is very important. If the application creates tasks with
+ stacks larger then the minimum, then that memory is NOT accounted for by
+ ``<rtems/confdefs.h>``.
+
+.. index:: CONFIGURE_INITIAL_EXTENSIONS
+
+.. _CONFIGURE_INITIAL_EXTENSIONS:
+
+CONFIGURE_INITIAL_EXTENSIONS
+----------------------------
+
+CONSTANT:
+ ``CONFIGURE_INITIAL_EXTENSIONS``
+
+DATA TYPE:
+ List of user extension initializers (``rtems_extensions_table``).
+
+RANGE:
+ Undefined or a list of one or more user extensions.
+
+DEFAULT VALUE:
+ This is not defined by default.
+
+DESCRIPTION:
+ If ``CONFIGURE_INITIAL_EXTENSIONS`` is defined by the application, then
+ this application specific set of initial extensions will be placed in the
+ initial extension table.
+
+NOTES:
+ None.
+
+.. index:: CONFIGURE_INTERRUPT_STACK_SIZE
+.. index:: interrupt stack size
+
+.. _CONFIGURE_INTERRUPT_STACK_SIZE:
+
+CONFIGURE_INTERRUPT_STACK_SIZE
+------------------------------
+
+CONSTANT:
+ ``CONFIGURE_INTERRUPT_STACK_SIZE``
+
+DATA TYPE:
+ Unsigned integer.
+
+RANGE:
+ Positive.
+
+DEFAULT VALUE:
+ The default value is ``BSP_INTERRUPT_STACK_SIZE`` in case it is defined,
+ otherwise the default value is ``CPU_STACK_MINIMUM_SIZE``.
+
+DESCRIPTION:
+ The ``CONFIGURE_INTERRUPT_STACK_SIZE`` configuration option defines the
+ size of an interrupt stack in bytes.
+
+NOTES:
+ The interrupt stack size must be aligned according to
+ ``CPU_INTERRUPT_STACK_ALIGNMENT``.
+
+ There is one interrupt stack available for each configured processor
+ (:ref:`CONFIGURE_MAXIMUM_PROCESSORS <CONFIGURE_MAXIMUM_PROCESSORS>`). The
+ interrupt stack areas are statically allocated in a special linker section
+ (``.rtemsstack.interrupt``). The placement of this linker section is
+ BSP-specific.
+
+ Some BSPs use the interrupt stack as the initialization stack which is used
+ to perform the sequential system initialization before the multithreading
+ is started.
+
+ The interrupt stacks are covered by the :ref:`stack checker
+ <CONFIGURE_STACK_CHECKER_ENABLED>`. However, using a too small interrupt
+ stack size may still result in undefined behaviour.
+
+ In releases before RTEMS 5.1 the default value was
+ :ref:`CONFIGURE_MINIMUM_TASK_STACK_SIZE
+ <CONFIGURE_MINIMUM_TASK_STACK_SIZE>` instead of ``CPU_STACK_MINIMUM_SIZE``.
+
+.. index:: CONFIGURE_MAXIMUM_FILE_DESCRIPTORS
+.. index:: maximum file descriptors
+
+.. _CONFIGURE_MAXIMUM_FILE_DESCRIPTORS:
+
+CONFIGURE_MAXIMUM_FILE_DESCRIPTORS
+----------------------------------
+
+CONSTANT:
+ ``CONFIGURE_MAXIMUM_FILE_DESCRIPTORS``
+
+DATA TYPE:
+ Unsigned integer (``uint32_t``).
+
+RANGE:
+ Zero or positive.
+
+DEFAULT VALUE:
+ If ``CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER`` is defined, then the
+ default value is 3, otherwise the default value is 0. Three file
+ descriptors allows RTEMS to support standard input, output, and error I/O
+ streams on ``/dev/console``.
+
+DESCRIPTION:
+ This configuration parameter is set to the maximum number of file like
+ objects that can be concurrently open.
+
+NOTES:
+ None.
+
+.. index:: CONFIGURE_MAXIMUM_PRIORITY
+.. index:: maximum priority
+.. index:: number of priority levels
+
+.. _CONFIGURE_MAXIMUM_PRIORITY:
+
+CONFIGURE_MAXIMUM_PRIORITY
+--------------------------
+
+CONSTANT:
+ ``CONFIGURE_MAXIMUM_PRIORITY``
+
+DATA TYPE:
+ Unsigned integer (``uint8_t``).
+
+RANGE:
+ Valid values for this configuration parameter must be one (1) less than
+ than a power of two (2) between 4 and 256 inclusively. In other words,
+ valid values are 3, 7, 31, 63, 127, and 255.
+
+DEFAULT VALUE:
+ The default value is 255, because RTEMS must support 256 priority levels to
+ be compliant with various standards. These priorities range from zero (0)
+ to 255.
+
+DESCRIPTION:
+ For the schedulers
+
+ * :ref:`SchedulerPriority`, which is the default in uniprocessor
+ configurations and can be configured through the
+ :ref:`CONFIGURE_SCHEDULER_PRIORITY` configuration option,
+
+ * :ref:`SchedulerSMPPriority` which can be configured through the
+ :ref:`CONFIGURE_SCHEDULER_PRIORITY_SMP` configuration option, and
+
+ * :ref:`SchedulerSMPPriorityAffinity` which can be configured through the
+ :ref:`CONFIGURE_SCHEDULER_PRIORITY_AFFINITY_SMP` configuration option
+
+ this configuration option specifies the maximum numeric priority of any task
+ for these schedulers and one less that the number of priority levels for
+ these schedulers. For all other schedulers provided by RTEMS, this
+ configuration option has no effect.
+
+NOTES:
+ The numerically greatest priority is the logically lowest priority in the
+ system and will thus be used by the IDLE task.
+
+ Priority zero (0) is reserved for internal use by RTEMS and is not available
+ to applications.
+
+ Reducing the number of priorities through this configuration option reduces
+ the amount of memory allocated by the schedulers listed above. These
+ schedulers use a chain control structure per priority and this structure
+ consists of three pointers. On a 32-bit architecture, the allocated memory
+ is 12 bytes * (``CONFIGURE_MAXIMUM_PRIORITY`` + 1), e.g. 3072 bytes for 256
+ priority levels (default), 48 bytes for 4 priority levels
+ (``CONFIGURE_MAXIMUM_PRIORITY == 3``).
+
+.. index:: CONFIGURE_MAXIMUM_PROCESSORS
+
+.. _CONFIGURE_MAXIMUM_PROCESSORS:
+
+CONFIGURE_MAXIMUM_PROCESSORS
+----------------------------
+
+CONSTANT:
+ ``CONFIGURE_MAXIMUM_PROCESSORS``
+
+DATA TYPE:
+ Unsigned integer (``uint32_t``).
+
+RANGE:
+ Positive.
+
+DEFAULT VALUE:
+ The default value is 1.
+
+DESCRIPTION:
+ ``CONFIGURE_MAXIMUM_PROCESSORS`` must be set to the maximum number of
+ processors an application intends to use. The number of actually available
+ processors depends on the hardware and may be less. It is recommended to
+ use the smallest value suitable for the application in order to save
+ memory. Each processor needs an idle thread and interrupt stack for
+ example.
+
+NOTES:
+ If there are more processors available than configured, the rest will be
+ ignored. This configuration define is ignored in uniprocessor
+ configurations.
+
+.. index:: CONFIGURE_MAXIMUM_THREAD_NAME_SIZE
+.. index:: maximum thread name size
+
+.. _CONFIGURE_MAXIMUM_THREAD_NAME_SIZE:
+
+CONFIGURE_MAXIMUM_THREAD_NAME_SIZE
+----------------------------------
+
+CONSTANT:
+ ``CONFIGURE_MAXIMUM_THREAD_NAME_SIZE``
+
+DATA TYPE:
+ Unsigned integer (``size_t``).
+
+RANGE:
+ No restrictions.
+
+DEFAULT VALUE:
+ The default value is 16. This value was chosen for Linux compatibility,
+ see
+ `PTHREAD_SETNAME_NP(3) <http://man7.org/linux/man-pages/man3/pthread_setname_np.3.html>`_.
+
+DESCRIPTION:
+ This configuration parameter specifies the maximum thread name size
+ including the terminating `NUL` character.
+
+NOTE:
+ The size of the thread control block is increased by the maximum thread name
+ size. This configuration option is available since RTEMS 5.1.
+
+.. index:: CONFIGURE_MEMORY_OVERHEAD
+
+.. _CONFIGURE_MEMORY_OVERHEAD:
+
+CONFIGURE_MEMORY_OVERHEAD
+-------------------------
+
+CONSTANT:
+ ``CONFIGURE_MEMORY_OVERHEAD``
+
+DATA TYPE:
+ Unsigned integer (``size_t``).
+
+RANGE:
+ Zero or positive.
+
+DEFAULT VALUE:
+ The default value is 0.
+
+DESCRIPTION:
+ This parameter is set to the number of kilobytes the application wishes to
+ add to the requirements calculated by ``<rtems/confdefs.h>``.
+
+NOTES:
+ This configuration parameter should only be used when it is suspected that
+ a bug in ``<rtems/confdefs.h>`` has resulted in an underestimation.
+ Typically the memory allocation will be too low when an application does
+ not account for all message queue buffers or task stacks.
+
+.. index:: CONFIGURE_MICROSECONDS_PER_TICK
+.. index:: tick quantum
+
+.. _CONFIGURE_MICROSECONDS_PER_TICK:
+
+CONFIGURE_MICROSECONDS_PER_TICK
+-------------------------------
+
+CONSTANT:
+ ``CONFIGURE_MICROSECONDS_PER_TICK``
+
+DATA TYPE:
+ Unsigned integer (``uint32_t``).
+
+RANGE:
+ Positive.
+
+DEFAULT VALUE:
+ This is not defined by default. When not defined, the clock tick quantum is
+ configured to be 10,000 microseconds which is ten (10) milliseconds.
+
+DESCRIPTION:
+ This constant is used to specify the length of time between clock ticks.
+
+ When the clock tick quantum value is too low, the system will spend so much
+ time processing clock ticks that it does not have processing time available
+ to perform application work. In this case, the system will become
+ unresponsive.
+
+ The lowest practical time quantum varies widely based upon the speed of the
+ target hardware and the architectural overhead associated with
+ interrupts. In general terms, you do not want to configure it lower than is
+ needed for the application.
+
+ The clock tick quantum should be selected such that it all blocking and
+ delay times in the application are evenly divisible by it. Otherwise,
+ rounding errors will be introduced which may negatively impact the
+ application.
+
+NOTES:
+ This configuration parameter has no impact if the Clock Tick Device driver
+ is not configured.
+
+ There may be BSP specific limits on the resolution or maximum value of a
+ clock tick quantum.
+
+.. index:: CONFIGURE_MINIMUM_TASK_STACK_SIZE
+.. index:: minimum task stack size
+
+.. _CONFIGURE_MINIMUM_TASK_STACK_SIZE:
+
+CONFIGURE_MINIMUM_TASK_STACK_SIZE
+---------------------------------
+
+CONSTANT:
+ ``CONFIGURE_MINIMUM_TASK_STACK_SIZE``
+
+DATA TYPE:
+ Unsigned integer (``uint32_t``).
+
+RANGE:
+ Positive.
+
+DEFAULT VALUE:
+ The default value is architecture-specific.
+
+DESCRIPTION:
+ This configuration parameter defines the minimum stack size in bytes for
+ every user task or thread in the system.
+
+NOTES:
+ Adjusting this parameter should be done with caution. Examining the actual
+ stack usage using the stack checker usage reporting facility is recommended
+ (see also :ref:`CONFIGURE_STACK_CHECKER_ENABLED <CONFIGURE_STACK_CHECKER_ENABLED>`).
+
+ This parameter can be used to lower the minimum from that recommended. This
+ can be used in low memory systems to reduce memory consumption for
+ stacks. However, this must be done with caution as it could increase the
+ possibility of a blown task stack.
+
+ This parameter can be used to increase the minimum from that
+ recommended. This can be used in higher memory systems to reduce the risk
+ of stack overflow without performing analysis on actual consumption.
+
+ By default, this configuration parameter defines also the minimum stack
+ size of POSIX threads. This can be changed with the
+ :ref:`CONFIGURE_MINIMUM_POSIX_THREAD_STACK_SIZE <CONFIGURE_MINIMUM_POSIX_THREAD_STACK_SIZE>`
+ configuration option.
+
+ In releases before RTEMS 5.1 the ``CONFIGURE_MINIMUM_TASK_STACK_SIZE`` was
+ used to define the default value of :ref:`CONFIGURE_INTERRUPT_STACK_SIZE
+ <CONFIGURE_INTERRUPT_STACK_SIZE>`.
+
+.. index:: CONFIGURE_STACK_CHECKER_ENABLED
+
+.. _CONFIGURE_STACK_CHECKER_ENABLED:
+
+CONFIGURE_STACK_CHECKER_ENABLED
+-------------------------------
+
+CONSTANT:
+ ``CONFIGURE_STACK_CHECKER_ENABLED``
+
+DATA TYPE:
+ Boolean feature macro.
+
+RANGE:
+ Defined or undefined.
+
+DEFAULT VALUE:
+ This is not defined by default, and thus stack checking is disabled.
+
+DESCRIPTION:
+ This configuration parameter is defined when the application wishes to
+ enable run-time stack bounds checking.
+
+NOTES:
+ In 4.9 and older, this configuration parameter was named ``STACK_CHECKER_ON``.
+
+ This increases the time required to create tasks as well as adding overhead
+ to each context switch.
+
+.. index:: CONFIGURE_TICKS_PER_TIMESLICE
+.. index:: ticks per timeslice
+
+.. _CONFIGURE_TICKS_PER_TIMESLICE:
+
+CONFIGURE_TICKS_PER_TIMESLICE
+-----------------------------
+
+CONSTANT:
+ ``CONFIGURE_TICKS_PER_TIMESLICE``
+
+DATA TYPE:
+ Unsigned integer (``uint32_t``).
+
+RANGE:
+ Positive.
+
+DEFAULT VALUE:
+ The default value is 50.
+
+DESCRIPTION:
+ This configuration parameter specifies the length of the timeslice quantum
+ in ticks for each task.
+
+NOTES:
+ This configuration parameter has no impact if the Clock Tick Device driver
+ is not configured.
+
+.. index:: CONFIGURE_UNIFIED_WORK_AREAS
+.. index:: unified work areas
+.. index:: separate work areas
+.. index:: RTEMS Workspace
+.. index:: C Program Heap
+
+.. _CONFIGURE_UNIFIED_WORK_AREAS:
+
+CONFIGURE_UNIFIED_WORK_AREAS
+----------------------------
+
+CONSTANT:
+ ``CONFIGURE_UNIFIED_WORK_AREAS``
+
+DATA TYPE:
+ Boolean feature macro.
+
+RANGE:
+ Defined or undefined.
+
+DEFAULT VALUE:
+ This is not defined by default, which specifies that the C Program Heap and
+ the RTEMS Workspace will be separate.
+
+DESCRIPTION:
+ When defined, the C Program Heap and the RTEMS Workspace will be one pool
+ of memory.
+
+ When not defined, there will be separate memory pools for the RTEMS
+ Workspace and C Program Heap.
+
+NOTES:
+ Having separate pools does have some advantages in the event a task blows a
+ stack or writes outside its memory area. However, in low memory systems the
+ overhead of the two pools plus the potential for unused memory in either
+ pool is very undesirable.
+
+ In high memory environments, this is desirable when you want to use the
+ RTEMS "unlimited" objects option. You will be able to create objects until
+ you run out of all available memory rather then just until you run out of
+ RTEMS Workspace.
+
+.. _CONFIGURE_UNLIMITED_ALLOCATION_SIZE:
+
+CONFIGURE_UNLIMITED_ALLOCATION_SIZE
+-----------------------------------
+
+CONSTANT:
+ ``CONFIGURE_UNLIMITED_ALLOCATION_SIZE``
+
+DATA TYPE:
+ Unsigned integer (``uint32_t``).
+
+RANGE:
+ Positive.
+
+DEFAULT VALUE:
+ If not defined and ``CONFIGURE_UNLIMITED_OBJECTS`` is defined, the default
+ value is eight (8).
+
+DESCRIPTION:
+ ``CONFIGURE_UNLIMITED_ALLOCATION_SIZE`` provides an allocation size to use
+ for ``rtems_resource_unlimited`` when using
+ ``CONFIGURE_UNLIMITED_OBJECTS``.
+
+NOTES:
+ By allowing users to declare all resources as being unlimited the user can
+ avoid identifying and limiting the resources
+ used. ``CONFIGURE_UNLIMITED_OBJECTS`` does not support varying the
+ allocation sizes for different objects; users who want that much control
+ can define the ``rtems_resource_unlimited`` macros themselves.
+
+.. index:: CONFIGURE_UNLIMITED_OBJECTS
+
+.. _CONFIGURE_UNLIMITED_OBJECTS:
+
+CONFIGURE_UNLIMITED_OBJECTS
+---------------------------
+
+CONSTANT:
+ ``CONFIGURE_UNLIMITED_OBJECTS``
+
+DATA TYPE:
+ Boolean feature macro.
+
+RANGE:
+ Defined or undefined.
+
+DEFAULT VALUE:
+ This is not defined by default.
+
+DESCRIPTION:
+ ``CONFIGURE_UNLIMITED_OBJECTS`` enables ``rtems_resource_unlimited`` mode
+ for Classic API and POSIX API objects that do not already have a specific
+ maximum limit defined.
+
+NOTES:
+ When using unlimited objects, it is common practice to also specify
+ ``CONFIGURE_UNIFIED_WORK_AREAS`` so the system operates with a single pool
+ of memory for both RTEMS and application memory allocations.
+
+.. index:: CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION
+
+.. _CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION:
+
+CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION
+---------------------------------------
+
+CONSTANT:
+ ``CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION``
+
+DATA TYPE:
+ Boolean feature macro.
+
+RANGE:
+ Defined or undefined.
+
+DEFAULT VALUE:
+ This is not defined by default, and thus the system initialization is
+ quiet.
+
+DESCRIPTION:
+ This configuration option enables to print some information during system
+ initialization.
+
+NOTES:
+ You may use this feature to debug system initialization issues. The
+ printk() function is used to print the information.
+
+.. index:: CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY
+.. index:: clear C Program Heap
+.. index:: clear RTEMS Workspace
+.. index:: zero C Program Heap
+.. index:: zero RTEMS Workspace
+
+.. _CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY:
+
+CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY
+--------------------------------------
+
+CONSTANT:
+ ``CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY``
+
+DATA TYPE:
+ Boolean feature macro.
+
+RANGE:
+ Defined or undefined.
+
+DEFAULT VALUE:
+ This is not defined by default. The default is *NOT* to zero out the RTEMS
+ Workspace or C Program Heap.
+
+DESCRIPTION:
+ This macro indicates whether RTEMS should zero the RTEMS Workspace and C
+ Program Heap as part of its initialization. If defined, the memory regions
+ are zeroed. Otherwise, they are not.
+
+NOTES:
+ Zeroing memory can add significantly to system boot time. It is not
+ necessary for RTEMS but is often assumed by support libraries. In case
+ :ref:`CONFIGURE_DIRTY_MEMORY` is also defined, then the memory is first
+ dirtied and then zeroed.
diff --git a/c-user/config/index.rst b/c-user/config/index.rst
index 982a258..acbdbe2 100644
--- a/c-user/config/index.rst
+++ b/c-user/config/index.rst
@@ -12,642 +12,7 @@ Configuring a System
.. toctree::
intro
-
-General System Configuration
-============================
-
-This section defines the general system configuration options supported by
-``<rtems/confdefs.h>``.
-
-.. index:: CONFIGURE_DIRTY_MEMORY
-
-.. _CONFIGURE_DIRTY_MEMORY:
-
-CONFIGURE_DIRTY_MEMORY
-----------------------
-
-CONSTANT:
- ``CONFIGURE_DIRTY_MEMORY``
-
-DATA TYPE:
- Boolean feature macro.
-
-RANGE:
- Defined or undefined.
-
-DEFAULT VALUE:
- By default, the memory used by the RTEMS Workspace and the C Program Heap
- is uninitialized memory.
-
-DESCRIPTION:
- This macro indicates whether RTEMS should dirty the memory used by the
- RTEMS Workspace and the C Program Heap as part of its initialization. If
- defined, the memory areas are dirtied with a ``0xCF`` byte pattern.
- Otherwise, they are not.
-
-NOTES:
- Dirtying memory can add significantly to system boot time. It may assist in
- finding code that incorrectly assumes the contents of free memory areas is
- cleared to zero during system initialization. In case
- :ref:`CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY` is also defined, then the
- memory is first dirtied and then zeroed.
-
-.. index:: CONFIGURE_EXTRA_TASK_STACKS
-.. index:: memory for task tasks
-
-.. _CONFIGURE_EXTRA_TASK_STACKS:
-
-CONFIGURE_EXTRA_TASK_STACKS
----------------------------
-
-CONSTANT:
- ``CONFIGURE_EXTRA_TASK_STACKS``
-
-DATA TYPE:
- Unsigned integer (``size_t``).
-
-RANGE:
- Undefined or positive.
-
-DEFAULT VALUE:
- The default value is 0.
-
-DESCRIPTION:
- This configuration parameter is set to the number of bytes the applications
- wishes to add to the task stack requirements calculated by
- ``<rtems/confdefs.h>``.
-
-NOTES:
- This parameter is very important. If the application creates tasks with
- stacks larger then the minimum, then that memory is NOT accounted for by
- ``<rtems/confdefs.h>``.
-
-.. index:: CONFIGURE_INITIAL_EXTENSIONS
-
-.. _CONFIGURE_INITIAL_EXTENSIONS:
-
-CONFIGURE_INITIAL_EXTENSIONS
-----------------------------
-
-CONSTANT:
- ``CONFIGURE_INITIAL_EXTENSIONS``
-
-DATA TYPE:
- List of user extension initializers (``rtems_extensions_table``).
-
-RANGE:
- Undefined or a list of one or more user extensions.
-
-DEFAULT VALUE:
- This is not defined by default.
-
-DESCRIPTION:
- If ``CONFIGURE_INITIAL_EXTENSIONS`` is defined by the application, then
- this application specific set of initial extensions will be placed in the
- initial extension table.
-
-NOTES:
- None.
-
-.. index:: CONFIGURE_INTERRUPT_STACK_SIZE
-.. index:: interrupt stack size
-
-.. _CONFIGURE_INTERRUPT_STACK_SIZE:
-
-CONFIGURE_INTERRUPT_STACK_SIZE
-------------------------------
-
-CONSTANT:
- ``CONFIGURE_INTERRUPT_STACK_SIZE``
-
-DATA TYPE:
- Unsigned integer.
-
-RANGE:
- Positive.
-
-DEFAULT VALUE:
- The default value is ``BSP_INTERRUPT_STACK_SIZE`` in case it is defined,
- otherwise the default value is ``CPU_STACK_MINIMUM_SIZE``.
-
-DESCRIPTION:
- The ``CONFIGURE_INTERRUPT_STACK_SIZE`` configuration option defines the
- size of an interrupt stack in bytes.
-
-NOTES:
- The interrupt stack size must be aligned according to
- ``CPU_INTERRUPT_STACK_ALIGNMENT``.
-
- There is one interrupt stack available for each configured processor
- (:ref:`CONFIGURE_MAXIMUM_PROCESSORS <CONFIGURE_MAXIMUM_PROCESSORS>`). The
- interrupt stack areas are statically allocated in a special linker section
- (``.rtemsstack.interrupt``). The placement of this linker section is
- BSP-specific.
-
- Some BSPs use the interrupt stack as the initialization stack which is used
- to perform the sequential system initialization before the multithreading
- is started.
-
- The interrupt stacks are covered by the :ref:`stack checker
- <CONFIGURE_STACK_CHECKER_ENABLED>`. However, using a too small interrupt
- stack size may still result in undefined behaviour.
-
- In releases before RTEMS 5.1 the default value was
- :ref:`CONFIGURE_MINIMUM_TASK_STACK_SIZE
- <CONFIGURE_MINIMUM_TASK_STACK_SIZE>` instead of ``CPU_STACK_MINIMUM_SIZE``.
-
-.. index:: CONFIGURE_MAXIMUM_FILE_DESCRIPTORS
-.. index:: maximum file descriptors
-
-.. _CONFIGURE_MAXIMUM_FILE_DESCRIPTORS:
-
-CONFIGURE_MAXIMUM_FILE_DESCRIPTORS
-----------------------------------
-
-CONSTANT:
- ``CONFIGURE_MAXIMUM_FILE_DESCRIPTORS``
-
-DATA TYPE:
- Unsigned integer (``uint32_t``).
-
-RANGE:
- Zero or positive.
-
-DEFAULT VALUE:
- If ``CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER`` is defined, then the
- default value is 3, otherwise the default value is 0. Three file
- descriptors allows RTEMS to support standard input, output, and error I/O
- streams on ``/dev/console``.
-
-DESCRIPTION:
- This configuration parameter is set to the maximum number of file like
- objects that can be concurrently open.
-
-NOTES:
- None.
-
-.. index:: CONFIGURE_MAXIMUM_PRIORITY
-.. index:: maximum priority
-.. index:: number of priority levels
-
-.. _CONFIGURE_MAXIMUM_PRIORITY:
-
-CONFIGURE_MAXIMUM_PRIORITY
---------------------------
-
-CONSTANT:
- ``CONFIGURE_MAXIMUM_PRIORITY``
-
-DATA TYPE:
- Unsigned integer (``uint8_t``).
-
-RANGE:
- Valid values for this configuration parameter must be one (1) less than
- than a power of two (2) between 4 and 256 inclusively. In other words,
- valid values are 3, 7, 31, 63, 127, and 255.
-
-DEFAULT VALUE:
- The default value is 255, because RTEMS must support 256 priority levels to
- be compliant with various standards. These priorities range from zero (0)
- to 255.
-
-DESCRIPTION:
- For the schedulers
-
- * :ref:`SchedulerPriority`, which is the default in uniprocessor
- configurations and can be configured through the
- :ref:`CONFIGURE_SCHEDULER_PRIORITY` configuration option,
-
- * :ref:`SchedulerSMPPriority` which can be configured through the
- :ref:`CONFIGURE_SCHEDULER_PRIORITY_SMP` configuration option, and
-
- * :ref:`SchedulerSMPPriorityAffinity` which can be configured through the
- :ref:`CONFIGURE_SCHEDULER_PRIORITY_AFFINITY_SMP` configuration option
-
- this configuration option specifies the maximum numeric priority of any task
- for these schedulers and one less that the number of priority levels for
- these schedulers. For all other schedulers provided by RTEMS, this
- configuration option has no effect.
-
-NOTES:
- The numerically greatest priority is the logically lowest priority in the
- system and will thus be used by the IDLE task.
-
- Priority zero (0) is reserved for internal use by RTEMS and is not available
- to applications.
-
- Reducing the number of priorities through this configuration option reduces
- the amount of memory allocated by the schedulers listed above. These
- schedulers use a chain control structure per priority and this structure
- consists of three pointers. On a 32-bit architecture, the allocated memory
- is 12 bytes * (``CONFIGURE_MAXIMUM_PRIORITY`` + 1), e.g. 3072 bytes for 256
- priority levels (default), 48 bytes for 4 priority levels
- (``CONFIGURE_MAXIMUM_PRIORITY == 3``).
-
-.. index:: CONFIGURE_MAXIMUM_PROCESSORS
-
-.. _CONFIGURE_MAXIMUM_PROCESSORS:
-
-CONFIGURE_MAXIMUM_PROCESSORS
-----------------------------
-
-CONSTANT:
- ``CONFIGURE_MAXIMUM_PROCESSORS``
-
-DATA TYPE:
- Unsigned integer (``uint32_t``).
-
-RANGE:
- Positive.
-
-DEFAULT VALUE:
- The default value is 1.
-
-DESCRIPTION:
- ``CONFIGURE_MAXIMUM_PROCESSORS`` must be set to the maximum number of
- processors an application intends to use. The number of actually available
- processors depends on the hardware and may be less. It is recommended to
- use the smallest value suitable for the application in order to save
- memory. Each processor needs an idle thread and interrupt stack for
- example.
-
-NOTES:
- If there are more processors available than configured, the rest will be
- ignored. This configuration define is ignored in uniprocessor
- configurations.
-
-.. index:: CONFIGURE_MAXIMUM_THREAD_NAME_SIZE
-.. index:: maximum thread name size
-
-.. _CONFIGURE_MAXIMUM_THREAD_NAME_SIZE:
-
-CONFIGURE_MAXIMUM_THREAD_NAME_SIZE
-----------------------------------
-
-CONSTANT:
- ``CONFIGURE_MAXIMUM_THREAD_NAME_SIZE``
-
-DATA TYPE:
- Unsigned integer (``size_t``).
-
-RANGE:
- No restrictions.
-
-DEFAULT VALUE:
- The default value is 16. This value was chosen for Linux compatibility,
- see
- `PTHREAD_SETNAME_NP(3) <http://man7.org/linux/man-pages/man3/pthread_setname_np.3.html>`_.
-
-DESCRIPTION:
- This configuration parameter specifies the maximum thread name size
- including the terminating `NUL` character.
-
-NOTE:
- The size of the thread control block is increased by the maximum thread name
- size. This configuration option is available since RTEMS 5.1.
-
-.. index:: CONFIGURE_MEMORY_OVERHEAD
-
-.. _CONFIGURE_MEMORY_OVERHEAD:
-
-CONFIGURE_MEMORY_OVERHEAD
--------------------------
-
-CONSTANT:
- ``CONFIGURE_MEMORY_OVERHEAD``
-
-DATA TYPE:
- Unsigned integer (``size_t``).
-
-RANGE:
- Zero or positive.
-
-DEFAULT VALUE:
- The default value is 0.
-
-DESCRIPTION:
- This parameter is set to the number of kilobytes the application wishes to
- add to the requirements calculated by ``<rtems/confdefs.h>``.
-
-NOTES:
- This configuration parameter should only be used when it is suspected that
- a bug in ``<rtems/confdefs.h>`` has resulted in an underestimation.
- Typically the memory allocation will be too low when an application does
- not account for all message queue buffers or task stacks.
-
-.. index:: CONFIGURE_MICROSECONDS_PER_TICK
-.. index:: tick quantum
-
-.. _CONFIGURE_MICROSECONDS_PER_TICK:
-
-CONFIGURE_MICROSECONDS_PER_TICK
--------------------------------
-
-CONSTANT:
- ``CONFIGURE_MICROSECONDS_PER_TICK``
-
-DATA TYPE:
- Unsigned integer (``uint32_t``).
-
-RANGE:
- Positive.
-
-DEFAULT VALUE:
- This is not defined by default. When not defined, the clock tick quantum is
- configured to be 10,000 microseconds which is ten (10) milliseconds.
-
-DESCRIPTION:
- This constant is used to specify the length of time between clock ticks.
-
- When the clock tick quantum value is too low, the system will spend so much
- time processing clock ticks that it does not have processing time available
- to perform application work. In this case, the system will become
- unresponsive.
-
- The lowest practical time quantum varies widely based upon the speed of the
- target hardware and the architectural overhead associated with
- interrupts. In general terms, you do not want to configure it lower than is
- needed for the application.
-
- The clock tick quantum should be selected such that it all blocking and
- delay times in the application are evenly divisible by it. Otherwise,
- rounding errors will be introduced which may negatively impact the
- application.
-
-NOTES:
- This configuration parameter has no impact if the Clock Tick Device driver
- is not configured.
-
- There may be BSP specific limits on the resolution or maximum value of a
- clock tick quantum.
-
-.. index:: CONFIGURE_MINIMUM_TASK_STACK_SIZE
-.. index:: minimum task stack size
-
-.. _CONFIGURE_MINIMUM_TASK_STACK_SIZE:
-
-CONFIGURE_MINIMUM_TASK_STACK_SIZE
----------------------------------
-
-CONSTANT:
- ``CONFIGURE_MINIMUM_TASK_STACK_SIZE``
-
-DATA TYPE:
- Unsigned integer (``uint32_t``).
-
-RANGE:
- Positive.
-
-DEFAULT VALUE:
- The default value is architecture-specific.
-
-DESCRIPTION:
- This configuration parameter defines the minimum stack size in bytes for
- every user task or thread in the system.
-
-NOTES:
- Adjusting this parameter should be done with caution. Examining the actual
- stack usage using the stack checker usage reporting facility is recommended
- (see also :ref:`CONFIGURE_STACK_CHECKER_ENABLED <CONFIGURE_STACK_CHECKER_ENABLED>`).
-
- This parameter can be used to lower the minimum from that recommended. This
- can be used in low memory systems to reduce memory consumption for
- stacks. However, this must be done with caution as it could increase the
- possibility of a blown task stack.
-
- This parameter can be used to increase the minimum from that
- recommended. This can be used in higher memory systems to reduce the risk
- of stack overflow without performing analysis on actual consumption.
-
- By default, this configuration parameter defines also the minimum stack
- size of POSIX threads. This can be changed with the
- :ref:`CONFIGURE_MINIMUM_POSIX_THREAD_STACK_SIZE <CONFIGURE_MINIMUM_POSIX_THREAD_STACK_SIZE>`
- configuration option.
-
- In releases before RTEMS 5.1 the ``CONFIGURE_MINIMUM_TASK_STACK_SIZE`` was
- used to define the default value of :ref:`CONFIGURE_INTERRUPT_STACK_SIZE
- <CONFIGURE_INTERRUPT_STACK_SIZE>`.
-
-.. index:: CONFIGURE_STACK_CHECKER_ENABLED
-
-.. _CONFIGURE_STACK_CHECKER_ENABLED:
-
-CONFIGURE_STACK_CHECKER_ENABLED
--------------------------------
-
-CONSTANT:
- ``CONFIGURE_STACK_CHECKER_ENABLED``
-
-DATA TYPE:
- Boolean feature macro.
-
-RANGE:
- Defined or undefined.
-
-DEFAULT VALUE:
- This is not defined by default, and thus stack checking is disabled.
-
-DESCRIPTION:
- This configuration parameter is defined when the application wishes to
- enable run-time stack bounds checking.
-
-NOTES:
- In 4.9 and older, this configuration parameter was named ``STACK_CHECKER_ON``.
-
- This increases the time required to create tasks as well as adding overhead
- to each context switch.
-
-.. index:: CONFIGURE_TICKS_PER_TIMESLICE
-.. index:: ticks per timeslice
-
-.. _CONFIGURE_TICKS_PER_TIMESLICE:
-
-CONFIGURE_TICKS_PER_TIMESLICE
------------------------------
-
-CONSTANT:
- ``CONFIGURE_TICKS_PER_TIMESLICE``
-
-DATA TYPE:
- Unsigned integer (``uint32_t``).
-
-RANGE:
- Positive.
-
-DEFAULT VALUE:
- The default value is 50.
-
-DESCRIPTION:
- This configuration parameter specifies the length of the timeslice quantum
- in ticks for each task.
-
-NOTES:
- This configuration parameter has no impact if the Clock Tick Device driver
- is not configured.
-
-.. index:: CONFIGURE_UNIFIED_WORK_AREAS
-.. index:: unified work areas
-.. index:: separate work areas
-.. index:: RTEMS Workspace
-.. index:: C Program Heap
-
-.. _CONFIGURE_UNIFIED_WORK_AREAS:
-
-CONFIGURE_UNIFIED_WORK_AREAS
-----------------------------
-
-CONSTANT:
- ``CONFIGURE_UNIFIED_WORK_AREAS``
-
-DATA TYPE:
- Boolean feature macro.
-
-RANGE:
- Defined or undefined.
-
-DEFAULT VALUE:
- This is not defined by default, which specifies that the C Program Heap and
- the RTEMS Workspace will be separate.
-
-DESCRIPTION:
- When defined, the C Program Heap and the RTEMS Workspace will be one pool
- of memory.
-
- When not defined, there will be separate memory pools for the RTEMS
- Workspace and C Program Heap.
-
-NOTES:
- Having separate pools does have some advantages in the event a task blows a
- stack or writes outside its memory area. However, in low memory systems the
- overhead of the two pools plus the potential for unused memory in either
- pool is very undesirable.
-
- In high memory environments, this is desirable when you want to use the
- RTEMS "unlimited" objects option. You will be able to create objects until
- you run out of all available memory rather then just until you run out of
- RTEMS Workspace.
-
-.. _CONFIGURE_UNLIMITED_ALLOCATION_SIZE:
-
-CONFIGURE_UNLIMITED_ALLOCATION_SIZE
------------------------------------
-
-CONSTANT:
- ``CONFIGURE_UNLIMITED_ALLOCATION_SIZE``
-
-DATA TYPE:
- Unsigned integer (``uint32_t``).
-
-RANGE:
- Positive.
-
-DEFAULT VALUE:
- If not defined and ``CONFIGURE_UNLIMITED_OBJECTS`` is defined, the default
- value is eight (8).
-
-DESCRIPTION:
- ``CONFIGURE_UNLIMITED_ALLOCATION_SIZE`` provides an allocation size to use
- for ``rtems_resource_unlimited`` when using
- ``CONFIGURE_UNLIMITED_OBJECTS``.
-
-NOTES:
- By allowing users to declare all resources as being unlimited the user can
- avoid identifying and limiting the resources
- used. ``CONFIGURE_UNLIMITED_OBJECTS`` does not support varying the
- allocation sizes for different objects; users who want that much control
- can define the ``rtems_resource_unlimited`` macros themselves.
-
-.. index:: CONFIGURE_UNLIMITED_OBJECTS
-
-.. _CONFIGURE_UNLIMITED_OBJECTS:
-
-CONFIGURE_UNLIMITED_OBJECTS
----------------------------
-
-CONSTANT:
- ``CONFIGURE_UNLIMITED_OBJECTS``
-
-DATA TYPE:
- Boolean feature macro.
-
-RANGE:
- Defined or undefined.
-
-DEFAULT VALUE:
- This is not defined by default.
-
-DESCRIPTION:
- ``CONFIGURE_UNLIMITED_OBJECTS`` enables ``rtems_resource_unlimited`` mode
- for Classic API and POSIX API objects that do not already have a specific
- maximum limit defined.
-
-NOTES:
- When using unlimited objects, it is common practice to also specify
- ``CONFIGURE_UNIFIED_WORK_AREAS`` so the system operates with a single pool
- of memory for both RTEMS and application memory allocations.
-
-.. index:: CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION
-
-.. _CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION:
-
-CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION
----------------------------------------
-
-CONSTANT:
- ``CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION``
-
-DATA TYPE:
- Boolean feature macro.
-
-RANGE:
- Defined or undefined.
-
-DEFAULT VALUE:
- This is not defined by default, and thus the system initialization is
- quiet.
-
-DESCRIPTION:
- This configuration option enables to print some information during system
- initialization.
-
-NOTES:
- You may use this feature to debug system initialization issues. The
- printk() function is used to print the information.
-
-.. index:: CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY
-.. index:: clear C Program Heap
-.. index:: clear RTEMS Workspace
-.. index:: zero C Program Heap
-.. index:: zero RTEMS Workspace
-
-.. _CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY:
-
-CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY
---------------------------------------
-
-CONSTANT:
- ``CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY``
-
-DATA TYPE:
- Boolean feature macro.
-
-RANGE:
- Defined or undefined.
-
-DEFAULT VALUE:
- This is not defined by default. The default is *NOT* to zero out the RTEMS
- Workspace or C Program Heap.
-
-DESCRIPTION:
- This macro indicates whether RTEMS should zero the RTEMS Workspace and C
- Program Heap as part of its initialization. If defined, the memory regions
- are zeroed. Otherwise, they are not.
-
-NOTES:
- Zeroing memory can add significantly to system boot time. It is not
- necessary for RTEMS but is often assumed by support libraries. In case
- :ref:`CONFIGURE_DIRTY_MEMORY` is also defined, then the memory is first
- dirtied and then zeroed.
+ general-config
Classic API Configuration
=========================
--
2.16.4
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