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diff --git a/c_user/configuring_a_system.rst b/c_user/configuring_a_system.rst index f33df6b..b55eea1 100644 --- a/c_user/configuring_a_system.rst +++ b/c_user/configuring_a_system.rst @@ -1,3 +1,7 @@ +.. COMMENT: COPYRIGHT (c) 1988-2008. +.. COMMENT: On-Line Applications Research Corporation (OAR). +.. COMMENT: All rights reserved. + Configuring a System #################### @@ -6,106 +10,111 @@ Configuring a System Introduction ============ -RTEMS must be configured for an application. This configuration -encompasses a variety of information including the length of each clock -tick, the maximum number of each information RTEMS object that can -be created, the application initialization tasks, the task scheduling -algorithm to be used, and the device drivers in the application. - -Although this information is contained in data structures that are used -by RTEMS at system initialization time, the data structures themselves -should only rarely to be generated by hand. RTEMS provides a set of -macros system which provides a simple standard mechanism to automate -the generation of these structures. +RTEMS must be configured for an application. This configuration encompasses a +variety of information including the length of each clock tick, the maximum +number of each information RTEMS object that can be created, the application +initialization tasks, the task scheduling algorithm to be used, and the device +drivers in the application. + +Although this information is contained in data structures that are used by +RTEMS at system initialization time, the data structures themselves should only +rarely to be generated by hand. RTEMS provides a set of macros system which +provides a simple standard mechanism to automate the generation of these +structures. + .. index:: confdefs.h .. index:: confdefs.h .. index:: <rtems/confdefs.h> .. index:: <rtems/confdefs.h> -The RTEMS header file ``<rtems/confdefs.h>`` is at the core of the -automatic generation of system configuration. It is based on the idea -of setting macros which define configuration parameters of interest to -the application and defaulting or calculating all others. This variety -of macros can automatically produce all of the configuration data -required for an RTEMS application. - -Trivia: ``confdefs`` is shorthand for a *Configuration Defaults*. - -As a general rule, application developers only specify values -for the configuration parameters of interest to them. They define what -resources or features they require. In most cases, when a parameter is -not specified, it defaults to zero (0) instances, a standards compliant -value, or disabled as appropriate. For example, by default there will be -256 task priority levels but this can be lowered by the application. This -number of priority levels is required to be compliant with the RTEID/ORKID -standards upon which the Classic API is based. There are similar cases -where the default is selected to be compliant with with the POSIX standard. +The RTEMS header file ``<rtems/confdefs.h>`` is at the core of the automatic +generation of system configuration. It is based on the idea of setting macros +which define configuration parameters of interest to the application and +defaulting or calculating all others. This variety of macros can automatically +produce all of the configuration data required for an RTEMS application. + +.. sidebar: Trivia: + + The term ``confdefs`` is shorthand for a *Configuration Defaults*. + +As a general rule, application developers only specify values for the +configuration parameters of interest to them. They define what resources or +features they require. In most cases, when a parameter is not specified, it +defaults to zero (0) instances, a standards compliant value, or disabled as +appropriate. For example, by default there will be 256 task priority levels but +this can be lowered by the application. This number of priority levels is +required to be compliant with the RTEID/ORKID standards upon which the Classic +API is based. There are similar cases where the default is selected to be +compliant with with the POSIX standard. For each configuration parameter in the configuration tables, the macro -corresponding to that field is discussed. The RTEMS Maintainers -expect that all systems can be easily configured using the``<rtems/confdefs.h>`` mechanism and that using this mechanism will -avoid internal RTEMS configuration changes impacting applications. +corresponding to that field is discussed. The RTEMS Maintainers expect that all +systems can be easily configured using the ``<rtems/confdefs.h>`` mechanism and +that using this mechanism will avoid internal RTEMS configuration changes +impacting applications. .. COMMENT: === Philosophy === Default Value Selection Philosophy ================================== -The user should be aware that the defaults are intentionally set as -low as possible. By default, no application resources are configured. -The ``<rtems/confdefs.h>`` file ensures that at least one application -task or thread is configured and that at least one of the initialization -task/thread tables is configured. +The user should be aware that the defaults are intentionally set as low as +possible. By default, no application resources are configured. The +``<rtems/confdefs.h>`` file ensures that at least one application task or +thread is configured and that at least one of the initialization task/thread +tables is configured. .. COMMENT: === Sizing the RTEMS Workspace === Sizing the RTEMS Workspace ========================== -The RTEMS Workspace is a user-specified block of memory reserved for -use by RTEMS. The application should NOT modify this memory. This area -consists primarily of the RTEMS data structures whose exact size depends -upon the values specified in the Configuration Table. In addition, -task stacks and floating point context areas are dynamically allocated -from the RTEMS Workspace. - -The ``<rtems/confdefs.h>`` mechanism calculates the size of the RTEMS -Workspace automatically. It assumes that all tasks are floating point and -that all will be allocated the minimum stack space. This calculation -includes the amount of memory that will be allocated for internal use -by RTEMS. The automatic calculation may underestimate the workspace -size truly needed by the application, in which case one can use the``CONFIGURE_MEMORY_OVERHEAD`` macro to add a value to the estimate. See `Specify Memory Overhead`_ for more details. +The RTEMS Workspace is a user-specified block of memory reserved for use by +RTEMS. The application should NOT modify this memory. This area consists +primarily of the RTEMS data structures whose exact size depends upon the values +specified in the Configuration Table. In addition, task stacks and floating +point context areas are dynamically allocated from the RTEMS Workspace. + +The ``<rtems/confdefs.h>`` mechanism calculates the size of the RTEMS Workspace +automatically. It assumes that all tasks are floating point and that all will +be allocated the minimum stack space. This calculation includes the amount of +memory that will be allocated for internal use by RTEMS. The automatic +calculation may underestimate the workspace size truly needed by the +application, in which case one can use the ``CONFIGURE_MEMORY_OVERHEAD`` macro +to add a value to the estimate. See :ref:`Specify Memory Overhead` for more +details. The memory area for the RTEMS Workspace is determined by the BSP. In case the RTEMS Workspace is too large for the available memory, then a fatal run-time error occurs and the system terminates. -The file ``<rtems/confdefs.h>`` will calculate the value of the``work_space_size`` parameter of the Configuration Table. There -are many parameters the application developer can specify to -help ``<rtems/confdefs.h>`` in its calculations. Correctly -specifying the application requirements via parameters such as``CONFIGURE_EXTRA_TASK_STACKS`` and ``CONFIGURE_MAXIMUM_TASKS`` -is critical for production software. - -For each class of objects, the allocation can operate in one of two ways. -The default way has an ceiling on the maximum number of object instances -which can concurrently exist in the system. Memory for all instances of -that object class is reserved at system initialization. The second -way allocates memory for an initial number of objects and increases the -current allocation by a fixed increment when required. Both ways allocate -space from inside the RTEMS Workspace. - -See `Unlimited Objects`_ for more details about -the second way, which allows for dynamic allocation of objects and -therefore does not provide determinism. This mode is useful mostly for -when the number of objects cannot be determined ahead of time or when -porting software for which you do not know the object requirements. - -The space needed for stacks and for RTEMS objects will vary from -one version of RTEMS and from one target processor to another. -Therefore it is safest to use ``<rtems/confdefs.h>`` and specify -your application's requirements in terms of the numbers of objects and -multiples of ``RTEMS_MINIMUM_STACK_SIZE``, as far as is possible. The -automatic estimates of space required will in general change when: +The file ``<rtems/confdefs.h>`` will calculate the value of +the``work_space_size`` parameter of the Configuration Table. There are many +parameters the application developer can specify to help ``<rtems/confdefs.h>`` +in its calculations. Correctly specifying the application requirements via +parameters such as ``CONFIGURE_EXTRA_TASK_STACKS`` and +``CONFIGURE_MAXIMUM_TASKS`` is critical for production software. + +For each class of objects, the allocation can operate in one of two ways. The +default way has an ceiling on the maximum number of object instances which can +concurrently exist in the system. Memory for all instances of that object class +is reserved at system initialization. The second way allocates memory for an +initial number of objects and increases the current allocation by a fixed +increment when required. Both ways allocate space from inside the RTEMS +Workspace. + +See :ref:`Unlimited Objects` for more details about the second way, which +allows for dynamic allocation of objects and therefore does not provide +determinism. This mode is useful mostly for when the number of objects cannot +be determined ahead of time or when porting software for which you do not know +the object requirements. + +The space needed for stacks and for RTEMS objects will vary from one version of +RTEMS and from one target processor to another. Therefore it is safest to use +``<rtems/confdefs.h>`` and specify your application's requirements in terms of +the numbers of objects and multiples of ``RTEMS_MINIMUM_STACK_SIZE``, as far as +is possible. The automatic estimates of space required will in general change +when: - a configuration parameter is changed, @@ -127,18 +136,19 @@ run-time errors terminating the system. Potential Issues with RTEMS Workspace Size Estimation ===================================================== -The ``<rtems/confdefs.h>`` file estimates the amount of memory -required for the RTEMS Workspace. This estimate is only as accurate -as the information given to ``<rtems/confdefs.h>`` and may be either -too high or too low for a variety of reasons. Some of the reasons that``<rtems/confdefs.h>`` may reserve too much memory for RTEMS are: +The ``<rtems/confdefs.h>`` file estimates the amount of memory required for the +RTEMS Workspace. This estimate is only as accurate as the information given to +``<rtems/confdefs.h>`` and may be either too high or too low for a variety of +reasons. Some of the reasons that ``<rtems/confdefs.h>`` may reserve too much +memory for RTEMS are: - All tasks/threads are assumed to be floating point. -Conversely, there are many more reasons that the resource estimate could be -too low: +Conversely, there are many more reasons that the resource estimate could be too +low: -- Task/thread stacks greater than minimum size must be - accounted for explicitly by developer. +- Task/thread stacks greater than minimum size must be accounted for explicitly + by developer. - Memory for messages is not included. @@ -149,53 +159,53 @@ too low: - Requirements for add-on libraries are not included. In general, ``<rtems/confdefs.h>`` is very accurate when given enough -information. However, it is quite easy to use a library and forget to -account for its resources. +information. However, it is quite easy to use a library and forget to account +for its resources. .. COMMENT: === Format to be followed for making changes in this file === Format to be followed for making changes in this file ===================================================== -- MACRO NAME +*MACRO NAME:*: Should be alphanumeric. Can have '_' (underscore). -- DATA TYPE +*DATA TYPE:* Please refer to all existing formats. -- RANGE: - +*RANGE:* The range depends on the Data Type of the macro. - - - If the data type is of type task priority, then its value should - be an integer in the range of 1 to 255. - - - If the data type is an integer, then it can have numbers, characters - (in case the value is defined using another macro) and arithmetic operations + - If the data type is of type task priority, then its value should be an + integer in the range of 1 to 255. + + - If the data type is an integer, then it can have numbers, characters (in + case the value is defined using another macro) and arithmetic operations (+, -, \*, /). - - - If the data type is a function pointer the first character - should be an alphabet or an underscore. The rest of the string - can be alphanumeric. - - - If the data type is RTEMS Attributes or RTEMS Mode then - the string should be alphanumeric. - - - If the data type is RTEMS NAME then the value should be - an integer>=0 or RTEMS_BUILD_NAME( 'U', 'I', '1', ' ' ) -- DEFAULT VALUE + - If the data type is a function pointer the first character should be an + alphabet or an underscore. The rest of the string can be alphanumeric. - The default value should be in the following formats- - Please note that the '.' (full stop) is necessary. + - If the data type is RTEMS Attributes or RTEMS Mode then the string should + be alphanumeric. - - - In case the value is not defined then: - This is not defined by default. - - - If we know the default value then: - The default value is XXX. - - - If the default value is BSP Specific then: - This option is BSP specific. + - If the data type is RTEMS NAME then the value should be an integer>=0 or + RTEMS_BUILD_NAME( 'U', 'I', '1', ' ' ) + +*DEFAULT VALUE:* + The default value should be in the following formats- Please note that the + '.' (full stop) is necessary. + + - In case the value is not defined then: This is not defined by default. -- DESCRIPTION + - If we know the default value then: The default value is XXX. + + - If the default value is BSP Specific then: This option is BSP specific. + +*DESCRIPTION:* The description of the macro. (No specific format) -- NOTES +*NOTES:* Any further notes. (No specific format) .. COMMENT: === Configuration Example === @@ -203,108 +213,108 @@ Format to be followed for making changes in this file Configuration Example ===================== -In the following example, the configuration information for a system -with a single message queue, four (4) tasks, and a timeslice of -fifty (50) milliseconds is as follows: +In the following example, the configuration information for a system with a +single message queue, four (4) tasks, and a timeslice of fifty (50) +milliseconds is as follows: + .. code:: c #include <bsp.h> #define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER #define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER - #define CONFIGURE_MICROSECONDS_PER_TICK 1000 /* 1 millisecond \*/ - #define CONFIGURE_TICKS_PER_TIMESLICE 50 /* 50 milliseconds \*/ + #define CONFIGURE_MICROSECONDS_PER_TICK 1000 /* 1 millisecond */ + #define CONFIGURE_TICKS_PER_TIMESLICE 50 /* 50 milliseconds */ #define CONFIGURE_RTEMS_INIT_TASKS_TABLE #define CONFIGURE_MAXIMUM_TASKS 4 #define CONFIGURE_MAXIMUM_MESSAGE_QUEUES 1 - #define CONFIGURE_MESSAGE_BUFFER_MEMORY \\ - CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE(20, sizeof(struct USER_MESSAGE)) + #define CONFIGURE_MESSAGE_BUFFER_MEMORY \ + CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE(20, sizeof(struct USER_MESSAGE)) #define CONFIGURE_INIT #include <rtems/confdefs.h> -In this example, only a few configuration parameters are specified. The -impact of these are as follows: - -- The example specified ``CONFIGURE_RTEMS_INIT_TASK_TABLE`` - but did not specify any additional parameters. This results in a - configuration of an application which will begin execution of a single - initialization task named ``Init`` which is non-preemptible and at - priority one (1). - -- By specifying ``CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER``, - this application is configured to have a clock tick device - driver. Without a clock tick device driver, RTEMS has no way to know - that time is passing and will be unable to support delays and wall - time. Further configuration details about time are - provided. Per ``CONFIGURE_MICROSECONDS_PER_TICK`` and``CONFIGURE_TICKS_PER_TIMESLICE``, the user specified they wanted a - clock tick to occur each millisecond, and that the length of a timeslice - would be fifty (50) milliseconds. - -- By specifying ``CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER``, - the application will include a console device driver. Although the - console device driver may support a combination of multiple serial - ports and display and keyboard combinations, it is only required to - provide a single device named ``/dev/console``. This device will - be used for Standard Input, Output and Error I/O Streams. Thus when``CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER`` is specified, implicitly - three (3) file descriptors are reserved for the Standard I/O Streams and - those file descriptors are associated with ``/dev/console`` during - initialization. All console devices are expected to support the POSIX*termios* interface. - -- The example above specifies via ``CONFIGURE_MAXIMUM_TASKS`` - that the application requires a maximum of four (4) - simultaneously existing Classic API tasks. Similarly, by specifying``CONFIGURE_MAXIMUM_MESSAGE_QUEUES``, there may be a maximum of only - one (1) concurrently existent Classic API message queues. - -- The most surprising configuration parameter in this example is the - use of ``CONFIGURE_MESSAGE_BUFFER_MEMORY``. Message buffer memory is - allocated from the RTEMS Workspace and must be accounted for. In this - example, the single message queue will have up to twenty (20) messages - of type ``struct USER_MESSAGE``. - -- The ``CONFIGURE_INIT`` constant must be defined in order to - make ``<rtems/confdefs.h>`` instantiate the configuration data - structures. This can only be defined in one source file per - application that includes ``<rtems/confdefs.h>`` or the symbol - table will be instantiated multiple times and linking errors - produced. - -This example illustrates that parameters have default values. Among -other things, the application implicitly used the following defaults: - -- All unspecified types of communications and synchronization objects - in the Classic and POSIX Threads API have maximums of zero (0). +In this example, only a few configuration parameters are specified. The impact +of these are as follows: + +- The example specified ``CONFIGURE_RTEMS_INIT_TASK_TABLE`` but did not specify + any additional parameters. This results in a configuration of an application + which will begin execution of a single initialization task named ``Init`` + which is non-preemptible and at priority one (1). + +- By specifying ``CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER``, this application + is configured to have a clock tick device driver. Without a clock tick device + driver, RTEMS has no way to know that time is passing and will be unable to + support delays and wall time. Further configuration details about time are + provided. Per ``CONFIGURE_MICROSECONDS_PER_TICK`` and + ``CONFIGURE_TICKS_PER_TIMESLICE``, the user specified they wanted a clock + tick to occur each millisecond, and that the length of a timeslice would be + fifty (50) milliseconds. + +- By specifying ``CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER``, the application + will include a console device driver. Although the console device driver may + support a combination of multiple serial ports and display and keyboard + combinations, it is only required to provide a single device named + ``/dev/console``. This device will be used for Standard Input, Output and + Error I/O Streams. Thus when ``CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER`` + is specified, implicitly three (3) file descriptors are reserved for the + Standard I/O Streams and those file descriptors are associated with + ``/dev/console`` during initialization. All console devices are expected to + support the POSIX*termios* interface. + +- The example above specifies via ``CONFIGURE_MAXIMUM_TASKS`` that the + application requires a maximum of four (4) simultaneously existing Classic + API tasks. Similarly, by specifying ``CONFIGURE_MAXIMUM_MESSAGE_QUEUES``, + there may be a maximum of only one (1) concurrently existent Classic API + message queues. + +- The most surprising configuration parameter in this example is the use of + ``CONFIGURE_MESSAGE_BUFFER_MEMORY``. Message buffer memory is allocated from + the RTEMS Workspace and must be accounted for. In this example, the single + message queue will have up to twenty (20) messages of type ``struct + USER_MESSAGE``. + +- The ``CONFIGURE_INIT`` constant must be defined in order to make + ``<rtems/confdefs.h>`` instantiate the configuration data structures. This + can only be defined in one source file per application that includes + ``<rtems/confdefs.h>`` or the symbol table will be instantiated multiple + times and linking errors produced. + +This example illustrates that parameters have default values. Among other +things, the application implicitly used the following defaults: + +- All unspecified types of communications and synchronization objects in the + Classic and POSIX Threads API have maximums of zero (0). - The filesystem will be the default filesystem which is the In-Memory File System (IMFS). - The application will have the default number of priority levels. -- The minimum task stack size will be that recommended by RTEMS for - the target architecture. +- The minimum task stack size will be that recommended by RTEMS for the target + architecture. .. COMMENT: === Unlimited Objects === - Unlimited Objects ----------------- -In real-time embedded systems the RAM is normally a limited, critical -resource and dynamic allocation is avoided as much as possible to -ensure predictable, deterministic execution times. For such cases, see `Sizing the RTEMS Workspace`_ for an overview -of how to tune the size of the workspace. Frequently when users are -porting software to RTEMS the precise resource requirements of the -software is unknown. In these situations users do not need to control -the size of the workspace very tightly because they just want to get +In real-time embedded systems the RAM is normally a limited, critical resource +and dynamic allocation is avoided as much as possible to ensure predictable, +deterministic execution times. For such cases, see :ref:`Sizing the RTEMS +Workspace` for an overview of how to tune the size of the workspace. +Frequently when users are porting software to RTEMS the precise resource +requirements of the software is unknown. In these situations users do not need +to control the size of the workspace very tightly because they just want to get the new software to run; later they can tune the workspace size as needed. -The following API-independent object classes can be configured in -unlimited mode: +The following API-independent object classes can be configured in unlimited +mode: - POSIX Keys - POSIX Key Value Pairs -The following object classes in the Classic API can be configured in -unlimited mode: +The following object classes in the Classic API can be configured in unlimited +mode: - Tasks @@ -324,8 +334,8 @@ unlimited mode: - Ports -Additionally, the following object classes from the POSIX API can be -configured in unlimited mode: +Additionally, the following object classes from the POSIX API can be configured +in unlimited mode: - Threads @@ -358,12 +368,13 @@ The following object classes can *not* be configured in unlimited mode: - POSIX Queued Signals Due to the memory requirements of unlimited objects it is strongly recommended -to use them only in combination with the unified work areas. See `Separate or Unified Work Areas`_ for more information -on unified work areas. +to use them only in combination with the unified work areas. See :ref:`Separate +or Unified Work Areas` for more information on unified work areas. The following example demonstrates how the two simple configuration defines for unlimited objects and unified works areas can replace many seperate configuration defines for supported object classes: + .. code:: c #define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER @@ -375,10 +386,10 @@ configuration defines for supported object classes: #include <rtems/confdefs.h> Users are cautioned that using unlimited objects is not recommended for -production software unless the dynamic growth is absolutely required. It -is generally considered a safer embedded systems programming practice to -know the system limits rather than experience an out of memory error -at an arbitrary and largely unpredictable time in the field. +production software unless the dynamic growth is absolutely required. It is +generally considered a safer embedded systems programming practice to know the +system limits rather than experience an out of memory error at an arbitrary and +largely unpredictable time in the field. .. COMMENT: === Per Object Class Unlimited Object Instances === @@ -387,16 +398,17 @@ Per Object Class Unlimited Object Instances .. index:: rtems_resource_unlimited When the number of objects is not known ahead of time, RTEMS provides an -auto-extending mode that can be enabled individually for each object -type by using the macro ``rtems_resource_unlimited``. This takes a value -as a parameter, and is used to set the object maximum number field in -an API Configuration table. The value is an allocation unit size. When -RTEMS is required to grow the object table it is grown by this -size. The kernel will return the object memory back to the RTEMS Workspace -when an object is destroyed. The kernel will only return an allocated -block of objects to the RTEMS Workspace if at least half the allocation -size of free objects remain allocated. RTEMS always keeps one -allocation block of objects allocated. Here is an example of using``rtems_resource_unlimited``: +auto-extending mode that can be enabled individually for each object type by +using the macro ``rtems_resource_unlimited``. This takes a value as a +parameter, and is used to set the object maximum number field in an API +Configuration table. The value is an allocation unit size. When RTEMS is +required to grow the object table it is grown by this size. The kernel will +return the object memory back to the RTEMS Workspace when an object is +destroyed. The kernel will only return an allocated block of objects to the +RTEMS Workspace if at least half the allocation size of free objects remain +allocated. RTEMS always keeps one allocation block of objects allocated. Here +is an example of using ``rtems_resource_unlimited``: + .. code:: c #define CONFIGURE_MAXIMUM_TASKS rtems_resource_unlimited(5) @@ -404,18 +416,19 @@ allocation block of objects allocated. Here is an example of using``rtems_resour .. index:: rtems_resource_is_unlimited .. index:: rtems_resource_maximum_per_allocation -Object maximum specifications can be evaluated with the``rtems_resource_is_unlimited`` and``rtems_resource_maximum_per_allocation`` macros. +Object maximum specifications can be evaluated with the +``rtems_resource_is_unlimited`` and``rtems_resource_maximum_per_allocation`` +macros. .. COMMENT: === Unlimited Object Instances === Unlimited Object Instances -------------------------- -To ease the burden of developers who are porting new software RTEMS -also provides the capability to make all object classes listed above -operate in unlimited mode in a simple manner. The application developer -is only responsible for enabling unlimited objects and specifying the -allocation size. +To ease the burden of developers who are porting new software RTEMS also +provides the capability to make all object classes listed above operate in +unlimited mode in a simple manner. The application developer is only +responsible for enabling unlimited objects and specifying the allocation size. .. COMMENT: === CONFIGURE_UNLIMITED_OBJECTS === @@ -437,14 +450,15 @@ Enable Unlimited Object Instances **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. +``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. +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. .. COMMENT: === CONFIGURE_UNLIMITED_ALLOCATION_SIZE === @@ -460,21 +474,22 @@ Specify Unlimited Objects Allocation Size *RANGE:* Positive. -*DEFAULT VALUE:* - If not defined and ``CONFIGURE_UNLIMITED_OBJECTS`` is defined, the - default value is eight (8). +*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``. +``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. +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. + .. code:: c #define CONFIGURE_UNLIMITED_OBJECTS @@ -485,8 +500,8 @@ the ``rtems_resource_unlimited`` macros themselves. Classic API Configuration ========================= -This section defines the Classic API related system configuration -parameters supported by ``<rtems/confdefs.h>``. +This section defines the Classic API related system configuration parameters +supported by ``<rtems/confdefs.h>``. .. COMMENT: === CONFIGURE_MAXIMUM_TASKS === @@ -508,27 +523,29 @@ Specify Maximum Classic API Tasks **DESCRIPTION:** -``CONFIGURE_MAXIMUM_TASKS`` is the maximum number of Classic API -Tasks that can be concurrently active. +``CONFIGURE_MAXIMUM_TASKS`` is the maximum number of Classic API Tasks that can +be concurrently active. **NOTES:** This object class can be configured in unlimited allocation mode. -The calculations for the required memory in the RTEMS Workspace -for tasks assume that each task has a minimum stack size and -has floating point support enabled. The configuration parameter``CONFIGURE_EXTRA_TASK_STACKS`` is used to specify task stack -requirements *ABOVE* the minimum size required. See `Reserve Task/Thread Stack Memory Above Minimum`_ -for more information about ``CONFIGURE_EXTRA_TASK_STACKS``. +The calculations for the required memory in the RTEMS Workspace for tasks +assume that each task has a minimum stack size and has floating point support +enabled. The configuration parameter ``CONFIGURE_EXTRA_TASK_STACKS`` is used +to specify task stack requirements *ABOVE* the minimum size required. See +:ref:`Reserve Task/Thread Stack Memory Above Minimum` for more information +about ``CONFIGURE_EXTRA_TASK_STACKS``. -The maximum number of POSIX threads is specified by``CONFIGURE_MAXIMUM_POSIX_THREADS``. +The maximum number of POSIX threads is specified by +``CONFIGURE_MAXIMUM_POSIX_THREADS``. .. COMMENT: XXX - Add xref to CONFIGURE_MAXIMUM_POSIX_THREADS. -A future enhancement to ``<rtems/confdefs.h>`` could be to eliminate -the assumption that all tasks have floating point enabled. This would -require the addition of a new configuration parameter to specify the -number of tasks which enable floating point support. +A future enhancement to ``<rtems/confdefs.h>`` could be to eliminate the +assumption that all tasks have floating point enabled. This would require the +addition of a new configuration parameter to specify the number of tasks which +enable floating point support. .. COMMENT: === CONFIGURE_MAXIMUM_TIMERS === @@ -550,8 +567,8 @@ Specify Maximum Classic API Timers **DESCRIPTION:** -``CONFIGURE_MAXIMUM_TIMERS`` is the maximum number of Classic API -Timers that can be concurrently active. +``CONFIGURE_MAXIMUM_TIMERS`` is the maximum number of Classic API Timers that +can be concurrently active. **NOTES:** @@ -577,8 +594,8 @@ Specify Maximum Classic API Semaphores **DESCRIPTION:** -``CONFIGURE_MAXIMUM_SEMAPHORES`` is the maximum number of Classic -API Semaphores that can be concurrently active. +``CONFIGURE_MAXIMUM_SEMAPHORES`` is the maximum number of Classic API +Semaphores that can be concurrently active. **NOTES:** @@ -604,9 +621,9 @@ Specify Maximum Classic API Semaphores usable with MrsP **DESCRIPTION:** -``CONFIGURE_MAXIMUM_MRSP_SEMAPHORES`` is the -maximum number of Classic API Semaphores using the Multiprocessor Resource -Sharing Protocol (MrsP) that can be concurrently active. +``CONFIGURE_MAXIMUM_MRSP_SEMAPHORES`` is the maximum number of Classic API +Semaphores using the Multiprocessor Resource Sharing Protocol (MrsP) that can +be concurrently active. **NOTES:** @@ -634,8 +651,8 @@ Specify Maximum Classic API Message Queues **DESCRIPTION:** -``CONFIGURE_MAXIMUM_MESSAGE_QUEUES`` is the maximum number of Classic -API Message Queues that can be concurrently active. +``CONFIGURE_MAXIMUM_MESSAGE_QUEUES`` is the maximum number of Classic API +Message Queues that can be concurrently active. **NOTES:** @@ -661,8 +678,8 @@ Specify Maximum Classic API Barriers **DESCRIPTION:** -``CONFIGURE_MAXIMUM_BARRIERS`` is the maximum number of Classic -API Barriers that can be concurrently active. +``CONFIGURE_MAXIMUM_BARRIERS`` is the maximum number of Classic API Barriers +that can be concurrently active. **NOTES:** @@ -688,8 +705,8 @@ Specify Maximum Classic API Periods **DESCRIPTION:** -``CONFIGURE_MAXIMUM_PERIODS`` is the maximum number of Classic -API Periods that can be concurrently active. +``CONFIGURE_MAXIMUM_PERIODS`` is the maximum number of Classic API Periods that +can be concurrently active. **NOTES:** @@ -715,8 +732,8 @@ Specify Maximum Classic API Partitions **DESCRIPTION:** -``CONFIGURE_MAXIMUM_PARTITIONS`` is the maximum number of Classic -API Partitions that can be concurrently active. +``CONFIGURE_MAXIMUM_PARTITIONS`` is the maximum number of Classic API +Partitions that can be concurrently active. **NOTES:** @@ -742,8 +759,8 @@ Specify Maximum Classic API Regions **DESCRIPTION:** -``CONFIGURE_MAXIMUM_REGIONS`` is the maximum number of Classic -API Regions that can be concurrently active. +``CONFIGURE_MAXIMUM_REGIONS`` is the maximum number of Classic API Regions that +can be concurrently active. **NOTES:** @@ -769,8 +786,8 @@ Specify Maximum Classic API Ports **DESCRIPTION:** -``CONFIGURE_MAXIMUM_PORTS`` is the maximum number of Classic -API Ports that can be concurrently active. +``CONFIGURE_MAXIMUM_PORTS`` is the maximum number of Classic API Ports that can +be concurrently active. **NOTES:** @@ -796,8 +813,8 @@ Specify Maximum Classic API User Extensions **DESCRIPTION:** -``CONFIGURE_MAXIMUM_USER_EXTENSIONS`` is the maximum number of Classic -API User Extensions that can be concurrently active. +``CONFIGURE_MAXIMUM_USER_EXTENSIONS`` is the maximum number of Classic API User +Extensions that can be concurrently active. **NOTES:** @@ -808,9 +825,9 @@ This object class can be configured in unlimited allocation mode. Classic API Initialization Tasks Table Configuration ==================================================== -The ``<rtems/confdefs.h>`` configuration system can automatically -generate an Initialization Tasks Table named``Initialization_tasks`` with a single entry. The following -parameters control the generation of that table. +The ``<rtems/confdefs.h>`` configuration system can automatically generate an +Initialization Tasks Table named ``Initialization_tasks`` with a single entry. +The following parameters control the generation of that table. .. COMMENT: === CONFIGURE_RTEMS_INIT_TASKS_TABLE === @@ -832,21 +849,21 @@ Instantiate Classic API Initialization Task Table **DESCRIPTION:** -``CONFIGURE_RTEMS_INIT_TASKS_TABLE`` is defined if the user wishes -to use a Classic RTEMS API Initialization Task Table. The table built by``<rtems/confdefs.h>`` specifies the parameters for a single task. This -is sufficient for applications which initialization the system from a -single task. +``CONFIGURE_RTEMS_INIT_TASKS_TABLE`` is defined if the user wishes to use a +Classic RTEMS API Initialization Task Table. The table built by +``<rtems/confdefs.h>`` specifies the parameters for a single task. This is +sufficient for applications which initialization the system from a single task. -By default, this field is not defined as the user MUST select their own -API for initialization tasks. +By default, this field is not defined as the user MUST select their own API for +initialization tasks. **NOTES:** -The application may choose to use the initialization tasks or threads -table from another API. +The application may choose to use the initialization tasks or threads table +from another API. -A compile time error will be generated if the user does not configure -any initialization tasks or threads. +A compile time error will be generated if the user does not configure any +initialization tasks or threads. .. COMMENT: === CONFIGURE_INIT_TASK_ENTRY_POINT === @@ -868,14 +885,14 @@ Specifying Classic API Initialization Task Entry Point **DESCRIPTION:** -``CONFIGURE_INIT_TASK_ENTRY_POINT`` is the entry point (a.k.a. function -name) of the single initialization task defined by the Classic API -Initialization Tasks Table. +``CONFIGURE_INIT_TASK_ENTRY_POINT`` is the entry point (a.k.a. function name) +of the single initialization task defined by the Classic API Initialization +Tasks Table. **NOTES:** -The user must implement the function ``Init`` or the function name provided -in this configuration parameter. +The user must implement the function ``Init`` or the function name provided in +this configuration parameter. .. COMMENT: === CONFIGURE_INIT_TASK_NAME === @@ -897,8 +914,8 @@ Specifying Classic API Initialization Task Name **DESCRIPTION:** -``CONFIGURE_INIT_TASK_NAME`` is the name of the single initialization -task defined by the Classic API Initialization Tasks Table. +``CONFIGURE_INIT_TASK_NAME`` is the name of the single initialization task +defined by the Classic API Initialization Tasks Table. **NOTES:** @@ -929,10 +946,10 @@ initialization task defined by the Classic API Initialization Tasks Table. **NOTES:** -If the stack size specified is greater than the configured minimum, -it must be accounted for in ``CONFIGURE_EXTRA_TASK_STACKS``. -See `Reserve Task/Thread Stack Memory Above Minimum`_ -for more information about ``CONFIGURE_EXTRA_TASK_STACKS``. +If the stack size specified is greater than the configured minimum, it must be +accounted for in ``CONFIGURE_EXTRA_TASK_STACKS``. See :ref:`Reserve +Task/Thread Stack Memory Above Minimum` for more information about +``CONFIGURE_EXTRA_TASK_STACKS``. .. COMMENT: === CONFIGURE_INIT_TASK_PRIORITY === @@ -1009,9 +1026,9 @@ Specifying Classic API Initialization Task Modes **DESCRIPTION:** -``CONFIGURE_INIT_TASK_INITIAL_MODES`` is the initial execution mode of -the single initialization task defined by the Classic API Initialization -Tasks Table. +``CONFIGURE_INIT_TASK_INITIAL_MODES`` is the initial execution mode of the +single initialization task defined by the Classic API Initialization Tasks +Table. **NOTES:** @@ -1064,23 +1081,23 @@ Not Using Generated Initialization Tasks Table **DESCRIPTION:** -``CONFIGURE_HAS_OWN_INIT_TASK_TABLE`` is defined if the user wishes -to define their own Classic API Initialization Tasks Table. This table -should be named ``Initialization_tasks``. +``CONFIGURE_HAS_OWN_INIT_TASK_TABLE`` is defined if the user wishes to define +their own Classic API Initialization Tasks Table. This table should be named +``Initialization_tasks``. **NOTES:** -This is a seldom used configuration parameter. The most likely use case -is when an application desires to have more than one initialization task. +This is a seldom used configuration parameter. The most likely use case is when +an application desires to have more than one initialization task. .. COMMENT: === POSIX API Configuration === POSIX API Configuration ======================= -The parameters in this section are used to configure resources -for the RTEMS POSIX API. They are only relevant if the POSIX API -is enabled at configure time using the ``--enable-posix`` option. +The parameters in this section are used to configure resources for the RTEMS +POSIX API. They are only relevant if the POSIX API is enabled at configure +time using the ``--enable-posix`` option. .. COMMENT: === CONFIGURE_MAXIMUM_POSIX_THREADS === @@ -1109,14 +1126,15 @@ Threads that can be concurrently active. This object class can be configured in unlimited allocation mode. -This calculations for the required memory in the RTEMS Workspace -for threads assume that each thread has a minimum stack size and -has floating point support enabled. The configuration parameter``CONFIGURE_EXTRA_TASK_STACKS`` is used to specify thread stack -requirements *ABOVE* the minimum size required. -See `Reserve Task/Thread Stack Memory Above Minimum`_ -for more information about ``CONFIGURE_EXTRA_TASK_STACKS``. +This calculations for the required memory in the RTEMS Workspace for threads +assume that each thread has a minimum stack size and has floating point support +enabled. The configuration parameter ``CONFIGURE_EXTRA_TASK_STACKS`` is used +to specify thread stack requirements *ABOVE* the minimum size required. See +:ref:`Reserve Task/Thread Stack Memory Above Minimum` for more information +about ``CONFIGURE_EXTRA_TASK_STACKS``. -The maximum number of Classic API Tasks is specified by``CONFIGURE_MAXIMUM_TASKS``. +The maximum number of Classic API Tasks is specified by +``CONFIGURE_MAXIMUM_TASKS``. All POSIX threads have floating point enabled. @@ -1142,8 +1160,8 @@ Specify Maximum POSIX API Mutexes **DESCRIPTION:** -``CONFIGURE_MAXIMUM_POSIX_MUTEXES`` is the maximum number of POSIX -API Mutexes that can be concurrently active. +``CONFIGURE_MAXIMUM_POSIX_MUTEXES`` is the maximum number of POSIX API Mutexes +that can be concurrently active. **NOTES:** @@ -1169,8 +1187,8 @@ Specify Maximum POSIX API Condition Variables **DESCRIPTION:** -``CONFIGURE_MAXIMUM_POSIX_CONDITION_VARIABLES`` is the maximum number -of POSIX API Condition Variables that can be concurrently active. +``CONFIGURE_MAXIMUM_POSIX_CONDITION_VARIABLES`` is the maximum number of POSIX +API Condition Variables that can be concurrently active. **NOTES:** @@ -1196,8 +1214,8 @@ Specify Maximum POSIX API Keys **DESCRIPTION:** -``CONFIGURE_MAXIMUM_POSIX_KEYS`` is the maximum number of POSIX -API Keys that can be concurrently active. +``CONFIGURE_MAXIMUM_POSIX_KEYS`` is the maximum number of POSIX API Keys that +can be concurrently active. **NOTES:** @@ -1225,8 +1243,8 @@ Specify Maximum POSIX API Timers **DESCRIPTION:** -``CONFIGURE_MAXIMUM_POSIX_TIMERS`` is the maximum number of POSIX -API Timers that can be concurrently active. +``CONFIGURE_MAXIMUM_POSIX_TIMERS`` is the maximum number of POSIX API Timers +that can be concurrently active. **NOTES:** @@ -1252,8 +1270,8 @@ Specify Maximum POSIX API Queued Signals **DESCRIPTION:** -``CONFIGURE_MAXIMUM_POSIX_QUEUED_SIGNALS`` is the maximum number of POSIX -API Queued Signals that can be concurrently active. +``CONFIGURE_MAXIMUM_POSIX_QUEUED_SIGNALS`` is the maximum number of POSIX API +Queued Signals that can be concurrently active. **NOTES:** @@ -1279,8 +1297,8 @@ Specify Maximum POSIX API Message Queues **DESCRIPTION:** -``CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUES`` is the maximum number of POSIX -API Message Queues that can be concurrently active. +``CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUES`` is the maximum number of POSIX API +Message Queues that can be concurrently active. **NOTES:** @@ -1308,16 +1326,15 @@ Specify Maximum POSIX API Message Queue Descriptors **DESCRIPTION:** -``CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUE_DESCRIPTORS`` is the maximum -number of POSIX API Message Queue Descriptors that can be concurrently -active. +``CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUE_DESCRIPTORS`` is the maximum number of +POSIX API Message Queue Descriptors that can be concurrently active. **NOTES:** This object class can be configured in unlimited allocation mode. -``CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUE_DESCRIPTORS`` should be -greater than or equal to ``CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUES``. +``CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUE_DESCRIPTORS`` should be greater than or +equal to ``CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUES``. .. COMMENT: === CONFIGURE_MAXIMUM_POSIX_SEMAPHORES === @@ -1339,8 +1356,8 @@ Specify Maximum POSIX API Semaphores **DESCRIPTION:** -``CONFIGURE_MAXIMUM_POSIX_SEMAPHORES`` is the maximum number of POSIX -API Semaphores that can be concurrently active. +``CONFIGURE_MAXIMUM_POSIX_SEMAPHORES`` is the maximum number of POSIX API +Semaphores that can be concurrently active. **NOTES:** @@ -1366,8 +1383,8 @@ Specify Maximum POSIX API Barriers **DESCRIPTION:** -``CONFIGURE_MAXIMUM_POSIX_BARRIERS`` is the maximum number of POSIX -API Barriers that can be concurrently active. +``CONFIGURE_MAXIMUM_POSIX_BARRIERS`` is the maximum number of POSIX API +Barriers that can be concurrently active. **NOTES:** @@ -1393,8 +1410,8 @@ Specify Maximum POSIX API Spinlocks **DESCRIPTION:** -``CONFIGURE_MAXIMUM_POSIX_SPINLOCKS`` is the maximum number of POSIX -API Spinlocks that can be concurrently active. +``CONFIGURE_MAXIMUM_POSIX_SPINLOCKS`` is the maximum number of POSIX API +Spinlocks that can be concurrently active. **NOTES:** @@ -1420,8 +1437,8 @@ Specify Maximum POSIX API Read/Write Locks **DESCRIPTION:** -``CONFIGURE_MAXIMUM_POSIX_RWLOCKS`` is the maximum number of POSIX -API Read/Write Locks that can be concurrently active. +``CONFIGURE_MAXIMUM_POSIX_RWLOCKS`` is the maximum number of POSIX API +Read/Write Locks that can be concurrently active. **NOTES:** @@ -1432,9 +1449,9 @@ This object class can be configured in unlimited allocation mode. POSIX Initialization Threads Table Configuration ================================================ -The ``<rtems/confdefs.h>`` configuration system can automatically -generate a POSIX Initialization Threads Table named``POSIX_Initialization_threads`` with a single entry. The following -parameters control the generation of that table. +The ``<rtems/confdefs.h>`` configuration system can automatically generate a +POSIX Initialization Threads Table named ``POSIX_Initialization_threads`` with +a single entry. The following parameters control the generation of that table. .. COMMENT: === CONFIGURE_POSIX_INIT_THREAD_TABLE === @@ -1452,28 +1469,26 @@ Instantiate POSIX API Initialization Thread Table Defined or undefined. *DEFAULT VALUE:* - This field is not defined by default, as the user MUST select their own - API for initialization tasks. + This field is not defined by default, as the user MUST select their own API + for initialization tasks. **DESCRIPTION:** -``CONFIGURE_POSIX_INIT_THREAD_TABLE`` is defined if the user wishes -to use a POSIX API Initialization Threads Table. The table built -by ``<rtems/confdefs.h>`` specifies the parameters for a single -thread. This is sufficient for applications which initialization the -system from a -single task. +``CONFIGURE_POSIX_INIT_THREAD_TABLE`` is defined if the user wishes to use a +POSIX API Initialization Threads Table. The table built by +``<rtems/confdefs.h>`` specifies the parameters for a single thread. This is +sufficient for applications which initialization the system from a single task. -By default, this field is not defined as the user MUST select their own -API for initialization tasks. +By default, this field is not defined as the user MUST select their own API for +initialization tasks. **NOTES:** -The application may choose to use the initialization tasks or threads -table from another API. +The application may choose to use the initialization tasks or threads table +from another API. -A compile time error will be generated if the user does not configure -any initialization tasks or threads. +A compile time error will be generated if the user does not configure any +initialization tasks or threads. .. COMMENT: === CONFIGURE_POSIX_INIT_THREAD_ENTRY_POINT === @@ -1495,9 +1510,9 @@ Specifying POSIX API Initialization Thread Entry Point **DESCRIPTION:** -``CONFIGURE_POSIX_INIT_THREAD_ENTRY_POINT`` is the entry point -(a.k.a. function name) of the single initialization thread defined by -the POSIX API Initialization Threads Table. +``CONFIGURE_POSIX_INIT_THREAD_ENTRY_POINT`` is the entry point (a.k.a. function +name) of the single initialization thread defined by the POSIX API +Initialization Threads Table. **NOTES:** @@ -1524,16 +1539,15 @@ Specifying POSIX API Initialization Thread Stack Size **DESCRIPTION:** -``CONFIGURE_POSIX_INIT_THREAD_STACK_SIZE`` is the stack size of the -single initialization thread defined by the POSIX API Initialization -Threads Table. +``CONFIGURE_POSIX_INIT_THREAD_STACK_SIZE`` is the stack size of the single +initialization thread defined by the POSIX API Initialization Threads Table. **NOTES:** -If the stack size specified is greater than the configured minimum, -it must be accounted for in ``CONFIGURE_EXTRA_TASK_STACKS``. -See `Reserve Task/Thread Stack Memory Above Minimum`_ -for more information about ``CONFIGURE_EXTRA_TASK_STACKS``. +If the stack size specified is greater than the configured minimum, it must be +accounted for in ``CONFIGURE_EXTRA_TASK_STACKS``. See `Reserve Task/Thread +Stack Memory Above Minimum`_ for more information about +``CONFIGURE_EXTRA_TASK_STACKS``. .. COMMENT: === CONFIGURE_POSIX_HAS_OWN_INIT_THREAD_TABLE === @@ -1555,21 +1569,22 @@ Not Using Generated POSIX Initialization Threads Table **DESCRIPTION:** -``CONFIGURE_POSIX_HAS_OWN_INIT_THREAD_TABLE`` is defined if the -user wishes to define their own POSIX API Initialization Threads Table. -This table should be named ``POSIX_Initialization_threads``. +``CONFIGURE_POSIX_HAS_OWN_INIT_THREAD_TABLE`` is defined if the user wishes to +define their own POSIX API Initialization Threads Table. This table should be +named ``POSIX_Initialization_threads``. **NOTES:** -This is a seldom used configuration parameter. The most likely use case -is when an application desires to have more than one initialization task. +This is a seldom used configuration parameter. The most likely use case is when +an application desires to have more than one initialization task. .. COMMENT: === Basic System Information === Basic System Information ======================== -This section defines the general system configuration parameters supported by``<rtems/confdefs.h>``. +This section defines the general system configuration parameters supported by +``<rtems/confdefs.h>``. .. COMMENT: === CONFIGURE_UNIFIED_WORK_AREAS === @@ -1592,28 +1607,28 @@ Separate or Unified Work Areas 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. + 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 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. +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. +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. +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. .. COMMENT: === CONFIGURE_MICROSECONDS_PER_TICK === @@ -1632,36 +1647,33 @@ Length of Each Clock Tick 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. + 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. +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 +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. +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. +There may be BSP specific limits on the resolution or maximum value of a clock +tick quantum. .. COMMENT: === CONFIGURE_TICKS_PER_TIMESLICE === @@ -1684,13 +1696,13 @@ Specifying Timeslicing Quantum **DESCRIPTION:** -This configuration parameter specifies the length of the timeslice -quantum in ticks for each task. +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. +This configuration parameter has no impact if the Clock Tick Device driver is +not configured. .. COMMENT: === CONFIGURE_MAXIMUM_PRIORITY === @@ -1712,31 +1724,31 @@ Specifying the Number of Thread Priority Levels 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. + 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:** -This configuration parameter specified the maximum numeric priority -of any task in the system and one less that the number of priority levels -in the system. +This configuration parameter specified the maximum numeric priority of any task +in the system and one less that the number of priority levels in the system. -Reducing the number of priorities in the system reduces the amount of -memory allocated from the RTEMS Workspace. +Reducing the number of priorities in the system reduces the amount of memory +allocated from the RTEMS Workspace. **NOTES:** -The numerically greatest priority is the logically lowest priority in -the system and will thus be used by the IDLE task. +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. +Priority zero (0) is reserved for internal use by RTEMS and is not available to +applications. -With some schedulers, reducing the number of priorities can reduce the -amount of memory used by the scheduler. For example, the Deterministic -Priority Scheduler (DPS) used by default uses three pointers of storage -per priority level. Reducing the number of priorities from 256 levels -to sixteen (16) can reduce memory usage by about three (3) kilobytes. +With some schedulers, reducing the number of priorities can reduce the amount +of memory used by the scheduler. For example, the Deterministic Priority +Scheduler (DPS) used by default uses three pointers of storage per priority +level. Reducing the number of priorities from 256 levels to sixteen (16) can +reduce memory usage by about three (3) kilobytes. .. COMMENT: === CONFIGURE_MINIMUM_TASK_STACK_SIZE === @@ -1760,22 +1772,22 @@ Specifying the Minimum Task Size **DESCRIPTION:** -The configuration parameter is set to the number of bytes the application -wants the minimum stack size to be for every task or thread in the system. +The configuration parameter is set to the number of bytes the application wants +the minimum stack size to be for every task or thread in the system. Adjusting this parameter should be done with caution. Examining the actual usage using the Stack Checker Usage Reporting facility is recommended. **NOTES:** -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 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. +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. .. COMMENT: === CONFIGURE_INTERRUPT_STACK_SIZE === @@ -1794,25 +1806,23 @@ Configuring the Size of the Interrupt Stack Positive. *DEFAULT VALUE:* - The default value is CONFIGURE_MINIMUM_TASK_STACK_SIZE, which is the minimum - interrupt stack size. + The default value is CONFIGURE_MINIMUM_TASK_STACK_SIZE, which is the + minimum interrupt stack size. **DESCRIPTION:** -``CONFIGURE_INTERRUPT_STACK_SIZE`` is set to the size of the -interrupt stack. The interrupt stack size is often set by the BSP but -since this memory may be allocated from the RTEMS Workspace, it must be -accounted for. +``CONFIGURE_INTERRUPT_STACK_SIZE`` is set to the size of the interrupt stack. +The interrupt stack size is often set by the BSP but since this memory may be +allocated from the RTEMS Workspace, it must be accounted for. **NOTES:** -In some BSPs, changing this constant does NOT change the -size of the interrupt stack, only the amount of memory -reserved for it. +In some BSPs, changing this constant does NOT change the size of the interrupt +stack, only the amount of memory reserved for it. -Patches which result in this constant only being used in memory -calculations when the interrupt stack is intended to be allocated -from the RTEMS Workspace would be welcomed by the RTEMS Project. +Patches which result in this constant only being used in memory calculations +when the interrupt stack is intended to be allocated from the RTEMS Workspace +would be welcomed by the RTEMS Project. .. COMMENT: === CONFIGURE_EXTRA_TASK_STACKS === @@ -1836,15 +1846,15 @@ Reserve Task/Thread Stack Memory Above Minimum **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>``. +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>``. +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>``. .. COMMENT: === CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY === @@ -1866,19 +1876,19 @@ Automatically Zeroing the RTEMS Workspace and C Program Heap Defined or undefined. *DEFAULT VALUE:* - This is not defined by default, unless overridden by the BSP. - The default is *NOT* to zero out the RTEMS Workspace or C Program Heap. + This is not defined by default, unless overridden by the BSP. 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. +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. +Zeroing memory can add significantly to system boot time. It is not necessary +for RTEMS but is often assumed by support libraries. .. COMMENT: === CONFIGURE_STACK_CHECKER_ENABLED === @@ -1900,15 +1910,15 @@ Enable The Task Stack Usage Checker **DESCRIPTION:** -This configuration parameter is defined when the application wishes to -enable run-time stack bounds checking. +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. +This increases the time required to create tasks as well as adding overhead to +each context switch. .. COMMENT: === CONFIGURE_INITIAL_EXTENSIONS === @@ -1930,9 +1940,9 @@ Specify Application Specific User Extensions **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. +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:** @@ -1944,9 +1954,9 @@ Configuring Custom Task Stack Allocation ======================================== RTEMS allows the application or BSP to define its own allocation and -deallocation methods for task stacks. This can be used to place task -stacks in special areas of memory or to utilize a Memory Management Unit -so that stack overflows are detected in hardware. +deallocation methods for task stacks. This can be used to place task stacks in +special areas of memory or to utilize a Memory Management Unit so that stack +overflows are detected in hardware. .. COMMENT: === CONFIGURE_TASK_STACK_ALLOCATOR_INIT === @@ -1964,14 +1974,13 @@ Custom Task Stack Allocator Initialization Undefined, NULL or valid function pointer. *DEFAULT VALUE:* - The default value is NULL, which indicates that - task stacks will be allocated from the RTEMS Workspace. + The default value is NULL, which indicates that task stacks will be + allocated from the RTEMS Workspace. **DESCRIPTION:** -``CONFIGURE_TASK_STACK_ALLOCATOR_INIT`` configures the initialization -method for an application or BSP specific task stack allocation -implementation. +``CONFIGURE_TASK_STACK_ALLOCATOR_INIT`` configures the initialization method +for an application or BSP specific task stack allocation implementation. **NOTES:** @@ -2001,13 +2010,13 @@ Custom Task Stack Allocator Undefined or valid function pointer. *DEFAULT VALUE:* - The default value is ``_Workspace_Allocate``, which indicates - that task stacks will be allocated from the RTEMS Workspace. + The default value is ``_Workspace_Allocate``, which indicates that task + stacks will be allocated from the RTEMS Workspace. **DESCRIPTION:** -``CONFIGURE_TASK_STACK_ALLOCATOR`` may point to a user provided -routine to allocate task stacks. +``CONFIGURE_TASK_STACK_ALLOCATOR`` may point to a user provided routine to +allocate task stacks. **NOTES:** @@ -2036,13 +2045,13 @@ Custom Task Stack Deallocator Undefined or valid function pointer. *DEFAULT VALUE:* - The default value is ``_Workspace_Free``, which indicates that - task stacks will be allocated from the RTEMS Workspace. + The default value is ``_Workspace_Free``, which indicates that task stacks + will be allocated from the RTEMS Workspace. **DESCRIPTION:** -``CONFIGURE_TASK_STACK_DEALLOCATOR`` may point to a user provided -routine to free task stacks. +``CONFIGURE_TASK_STACK_DEALLOCATOR`` may point to a user provided routine to +free task stacks. **NOTES:** @@ -2059,8 +2068,8 @@ A correctly configured system must configure the following to be consistent: Configuring Memory for Classic API Message Buffers ================================================== -This section describes the configuration parameters related to specifying -the amount of memory reserved for Classic API Message Buffers. +This section describes the configuration parameters related to specifying the +amount of memory reserved for Classic API Message Buffers. .. COMMENT: === CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE === @@ -2083,18 +2092,18 @@ Calculate Memory for a Single Classic Message API Message Queue **DESCRIPTION:** -This is a helper macro which is used to assist in computing the total -amount of memory required for message buffers. Each message queue will -have its own configuration with maximum message size and maximum number -of pending messages. +This is a helper macro which is used to assist in computing the total amount of +memory required for message buffers. Each message queue will have its own +configuration with maximum message size and maximum number of pending messages. The interface for this macro is as follows: + .. code:: c CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE(max_messages, size_per) -Where ``max_messages`` is the maximum number of pending messages -and ``size_per`` is the size in bytes of the user message. +Where ``max_messages`` is the maximum number of pending messages and +``size_per`` is the size in bytes of the user message. **NOTES:** @@ -2126,30 +2135,33 @@ reserved for pending Classic API Message Queue buffers. **NOTES:** -The following illustrates how the help macro``CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE`` can be used to assist in -calculating the message buffer memory required. In this example, there -are two message queues used in this application. The first message -queue has maximum of 24 pending messages with the message structure -defined by the type ``one_message_type``. The other message queue -has maximum of 500 pending messages with the message structure defined -by the type ``other_message_type``. +The following illustrates how the help macro +``CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE`` can be used to assist in calculating +the message buffer memory required. In this example, there are two message +queues used in this application. The first message queue has maximum of 24 +pending messages with the message structure defined by the type +``one_message_type``. The other message queue has maximum of 500 pending +messages with the message structure defined by the type ``other_message_type``. + .. code:: c - #define CONFIGURE_MESSAGE_BUFFER_MEMORY \\ - (CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \\ - 24, sizeof(one_message_type) + \\ - CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \\ - 500, sizeof(other_message_type) \\ - ) + #define CONFIGURE_MESSAGE_BUFFER_MEMORY \ + (CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \ + 24, sizeof(one_message_type) \ + ) + \ + CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \ + 500, sizeof(other_message_type) \ + ) .. COMMENT: === Seldom Used Configuration Parameters === Seldom Used Configuration Parameters ==================================== -This section describes configuration parameters supported by``<rtems/confdefs.h>`` which are seldom used by applications. These -parameters tend to be oriented to debugging system configurations -and providing work-arounds when the memory estimated by``<rtems/confdefs.h>`` is incorrect. +This section describes configuration parameters supported by +``<rtems/confdefs.h>`` which are seldom used by applications. These parameters +tend to be oriented to debugging system configurations and providing +work-arounds when the memory estimated by ``<rtems/confdefs.h>`` is incorrect. .. COMMENT: === CONFIGURE_MEMORY_OVERHEAD === @@ -2172,15 +2184,15 @@ Specify Memory Overhead **DESCRIPTION:** -Thie parameter is set to the number of kilobytes the application wishes -to add to the requirements calculated by ``<rtems/confdefs.h>``. +Thie 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. +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. .. COMMENT: === CONFIGURE_HAS_OWN_CONFIGURATION_TABLE === @@ -2202,8 +2214,8 @@ Do Not Generate Configuration Information **DESCRIPTION:** -This configuration parameter should only be defined if the application -is providing their own complete set of configuration tables. +This configuration parameter should only be defined if the application is +providing their own complete set of configuration tables. **NOTES:** @@ -2214,8 +2226,8 @@ None. C Library Support Configuration =============================== -This section defines the file system and IO library -related configuration parameters supported by``<rtems/confdefs.h>``. +This section defines the file system and IO library related configuration +parameters supported by ``<rtems/confdefs.h>``. .. COMMENT: === CONFIGURE_LIBIO_MAXIMUM_FILE_DESCRIPTORS === @@ -2235,9 +2247,9 @@ Specify Maximum Number of File Descriptors *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``. + 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:** @@ -2264,19 +2276,18 @@ Disable POSIX Termios Support Defined or undefined. *DEFAULT VALUE:* - This is not defined by default, and resources are reserved for the - termios functionality. + This is not defined by default, and resources are reserved for the termios + functionality. **DESCRIPTION:** -This configuration parameter is defined if the software implementing -POSIX termios functionality is not going to be used by this application. +This configuration parameter is defined if the software implementing POSIX +termios functionality is not going to be used by this application. **NOTES:** -The termios support library should not be included in an application -executable unless it is directly referenced by the application or a -device driver. +The termios support library should not be included in an application executable +unless it is directly referenced by the application or a device driver. .. COMMENT: === CONFIGURE_NUMBER_OF_TERMIOS_PORTS === @@ -2298,16 +2309,14 @@ Specify Maximum Termios Ports **DESCRIPTION:** -This configuration parameter is set to the number of ports using the -termios functionality. Each concurrently active termios port requires -resources. +This configuration parameter is set to the number of ports using the termios +functionality. Each concurrently active termios port requires resources. **NOTES:** -If the application will be using serial ports -including, but not limited to, the Console Device -(e.g. ``CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER``), then it is -highly likely that this configuration parameter should NOT be is defined. +If the application will be using serial ports including, but not limited to, +the Console Device (e.g. ``CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER``), then +it is highly likely that this configuration parameter should NOT be is defined. .. COMMENT: === File System Configuration Parameters === @@ -2336,11 +2345,11 @@ Providing Application Specific Mount Table **DESCRIPTION:** -This configuration parameter is defined when the application -provides their own filesystem mount table. The mount table is an -array of ``rtems_filesystem_mount_table_t`` entries pointed -to by the global variable ``rtems_filesystem_mount_table``. -The number of entries in this table is in an integer variable named``rtems_filesystem_mount_table_t``. +This configuration parameter is defined when the application provides their own +filesystem mount table. The mount table is an array of +``rtems_filesystem_mount_table_t`` entries pointed to by the global variable +``rtems_filesystem_mount_table``. The number of entries in this table is in an +integer variable named ``rtems_filesystem_mount_table_t``. .. COMMENT: XXX - is the variable name for the count right? @@ -2366,22 +2375,21 @@ Configure devFS as Root File System Defined or undefined. *DEFAULT VALUE:* - This is not defined by default. If no other root file system - configuration parameters are specified, the IMFS will be used as the - root file system. + This is not defined by default. If no other root file system configuration + parameters are specified, the IMFS will be used as the root file system. **DESCRIPTION:** -This configuration parameter is defined if the application wishes to -use the device-only filesytem as the root file system. +This configuration parameter is defined if the application wishes to use the +device-only filesytem as the root file system. **NOTES:** The device-only filesystem supports only device nodes and is smaller in executable code size than the full IMFS and miniIMFS. -The devFS is comparable in functionality to the pseudo-filesystem name -space provided before RTEMS release 4.5.0. +The devFS is comparable in functionality to the pseudo-filesystem name space +provided before RTEMS release 4.5.0. .. COMMENT: === CONFIGURE_MAXIMUM_DEVICES === @@ -2399,19 +2407,20 @@ Specifying Maximum Devices for devFS Positive. *DEFAULT VALUE:* - If ``BSP_MAXIMUM_DEVICES`` is defined, then the - default value is ``BSP_MAXIMUM_DEVICES``, otherwise the default value is 4. + If ``BSP_MAXIMUM_DEVICES`` is defined, then the default value is + ``BSP_MAXIMUM_DEVICES``, otherwise the default value is 4. **DESCRIPTION:** -``CONFIGURE_MAXIMUM_DEVICES`` is defined to the number of -individual devices that may be registered in the device file system (devFS). +``CONFIGURE_MAXIMUM_DEVICES`` is defined to the number of individual devices +that may be registered in the device file system (devFS). **NOTES:** This option is specific to the device file system (devFS) and should not be confused with the ``CONFIGURE_MAXIMUM_DRIVERS`` option. This parameter only -impacts the devFS and thus is only used by ``<rtems/confdefs.h>`` when``CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM`` is specified. +impacts the devFS and thus is only used by ``<rtems/confdefs.h>`` when +``CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM`` is specified. .. COMMENT: === CONFIGURE_APPLICATION_DISABLE_FILESYSTEM === @@ -2429,15 +2438,14 @@ Disable File System Support Defined or undefined. *DEFAULT VALUE:* - This is not defined by default. If no other root file system - configuration parameters are specified, the IMFS will be used as the - root file system. + This is not defined by default. If no other root file system configuration + parameters are specified, the IMFS will be used as the root file system. **DESCRIPTION:** -This configuration parameter is defined if the application dose not -intend to use any kind of filesystem support. This include the device -infrastructure necessary to support ``printf()``. +This configuration parameter is defined if the application dose not intend to +use any kind of filesystem support. This include the device infrastructure +necessary to support ``printf()``. **NOTES:** @@ -2496,8 +2504,8 @@ Specify Block Size for IMFS *RANGE:* Valid values for this configuration parameter are a power of two (2) - between 16 and 512 inclusive. In other words, valid values are 16, - 32, 64, 128, 256,and 512. + between 16 and 512 inclusive. In other words, valid values are 16, 32, 64, + 128, 256,and 512. *DEFAULT VALUE:* The default IMFS block size is 128 bytes. @@ -2505,36 +2513,31 @@ Specify Block Size for IMFS **DESCRIPTION:** This configuration parameter specifies the block size for in-memory files -managed by the IMFS. The configured block size has two impacts. The first -is the average amount of unused memory in the last block of each file. For -example, when the block size is 512, on average one-half of the last block -of each file will remain unused and the memory is wasted. In contrast, -when the block size is 16, the average unused memory per file is only -8 bytes. However, it requires more allocations for the same size file -and thus more overhead per block for the dynamic memory management. - -Second, the block size has an impact on the maximum size file that can -be stored in the IMFS. With smaller block size, the maximum file size -is correspondingly smaller. The following shows the maximum file size -possible based on the configured block size: - -- when the block size is 16 bytes, the maximum file size is 1,328 - bytes. +managed by the IMFS. The configured block size has two impacts. The first is +the average amount of unused memory in the last block of each file. For +example, when the block size is 512, on average one-half of the last block of +each file will remain unused and the memory is wasted. In contrast, when the +block size is 16, the average unused memory per file is only 8 bytes. However, +it requires more allocations for the same size file and thus more overhead per +block for the dynamic memory management. -- when the block size is 32 bytes, the maximum file size is 18,656 - bytes. +Second, the block size has an impact on the maximum size file that can be +stored in the IMFS. With smaller block size, the maximum file size is +correspondingly smaller. The following shows the maximum file size possible +based on the configured block size: -- when the block size is 64 bytes, the maximum file size is 279,488 - bytes. +- when the block size is 16 bytes, the maximum file size is 1,328 bytes. -- when the block size is 128 bytes, the maximum file size is - 4,329,344 bytes. +- when the block size is 32 bytes, the maximum file size is 18,656 bytes. -- when the block size is 256 bytes, the maximum file size is - 68,173,568 bytes. +- when the block size is 64 bytes, the maximum file size is 279,488 bytes. -- when the block size is 512 bytes, the maximum file size is - 1,082,195,456 bytes. +- when the block size is 128 bytes, the maximum file size is 4,329,344 bytes. + +- when the block size is 256 bytes, the maximum file size is 68,173,568 bytes. + +- when the block size is 512 bytes, the maximum file size is 1,082,195,456 + bytes. .. COMMENT: === CONFIGURE_IMFS_DISABLE_CHOWN === @@ -3191,8 +3194,9 @@ None. BSP Specific Settings ===================== -This section describes BSP specific configuration settings used by``<rtems/confdefs.h>``. The BSP specific configuration settings are -defined in ``<bsp.h>``. +This section describes BSP specific configuration settings used by +``<rtems/confdefs.h>``. The BSP specific configuration settings are defined in +``<bsp.h>``. .. COMMENT: === Disable BSP Settings === @@ -3214,8 +3218,8 @@ Disable BSP Configuration Settings **DESCRIPTION:** -All BSP specific configuration settings can be disabled by the application -with the ``CONFIGURE_DISABLE_BSP_SETTINGS`` option. +All BSP specific configuration settings can be disabled by the application with +the ``CONFIGURE_DISABLE_BSP_SETTINGS`` option. **NOTES:** @@ -3241,17 +3245,17 @@ Specify BSP Supports sbrk() **DESCRIPTION:** -This configuration parameter is defined by a BSP to indicate that it -does not allocate all available memory to the C Program Heap used by -the Malloc Family of routines. +This configuration parameter is defined by a BSP to indicate that it does not +allocate all available memory to the C Program Heap used by the Malloc Family +of routines. -If defined, when ``malloc()`` is unable to allocate memory, it will -call the BSP supplied ``sbrk()`` to obtain more memory. +If defined, when ``malloc()`` is unable to allocate memory, it will call the +BSP supplied ``sbrk()`` to obtain more memory. **NOTES:** -This parameter should not be defined by the application. Only the BSP -knows how it allocates memory to the C Program Heap. +This parameter should not be defined by the application. Only the BSP knows how +it allocates memory to the C Program Heap. .. COMMENT: === BSP_IDLE_TASK_BODY === @@ -3273,14 +3277,15 @@ Specify BSP Specific Idle Task **DESCRIPTION:** -If ``BSP_IDLE_TASK_BODY`` is defined by the BSP and``CONFIGURE_IDLE_TASK_BODY`` is not defined by the application, -then this BSP specific idle task body will be used. +If ``BSP_IDLE_TASK_BODY`` is defined by the BSP and +``CONFIGURE_IDLE_TASK_BODY`` is not defined by the application, then this BSP +specific idle task body will be used. **NOTES:** -As it has knowledge of the specific CPU model, system controller logic, -and peripheral buses, a BSP specific IDLE task may be capable of turning -components off to save power during extended periods of no task activity +As it has knowledge of the specific CPU model, system controller logic, and +peripheral buses, a BSP specific IDLE task may be capable of turning components +off to save power during extended periods of no task activity .. COMMENT: === BSP_IDLE_TASK_STACK_SIZE === @@ -3302,8 +3307,9 @@ Specify BSP Suggested Value for IDLE Task Stack Size **DESCRIPTION:** -If ``BSP_IDLE_TASK_STACK_SIZE`` is defined by the BSP and``CONFIGURE_IDLE_TASK_STACK_SIZE`` is not defined by the application, -then this BSP suggested idle task stack size will be used. +If ``BSP_IDLE_TASK_STACK_SIZE`` is defined by the BSP and +``CONFIGURE_IDLE_TASK_STACK_SIZE`` is not defined by the application, then this +BSP suggested idle task stack size will be used. **NOTES:** @@ -3339,9 +3345,9 @@ Specify BSP Specific User Extensions **DESCRIPTION:** -If ``BSP_INITIAL_EXTENSION`` is defined by the BSP, then this BSP -specific initial extension will be placed as the last entry in the initial -extension table. +If ``BSP_INITIAL_EXTENSION`` is defined by the BSP, then this BSP specific +initial extension will be placed as the last entry in the initial extension +table. **NOTES:** @@ -3367,8 +3373,9 @@ Specifying BSP Specific Interrupt Stack Size **DESCRIPTION:** -If ``BSP_INTERRUPT_STACK_SIZE`` is defined by the BSP and``CONFIGURE_INTERRUPT_STACK_SIZE`` is not defined by the application, -then this BSP specific interrupt stack size will be used. +If ``BSP_INTERRUPT_STACK_SIZE`` is defined by the BSP and +``CONFIGURE_INTERRUPT_STACK_SIZE`` is not defined by the application, then this +BSP specific interrupt stack size will be used. **NOTES:** @@ -3394,14 +3401,16 @@ Specifying BSP Specific Maximum Devices **DESCRIPTION:** -If ``BSP_MAXIMUM_DEVICES`` is defined by the BSP and``CONFIGURE_MAXIMUM_DEVICES`` is not defined by the application, -then this BSP specific maximum device count will be used. +If ``BSP_MAXIMUM_DEVICES`` is defined by the BSP and +``CONFIGURE_MAXIMUM_DEVICES`` is not defined by the application, then this BSP +specific maximum device count will be used. **NOTES:** This option is specific to the device file system (devFS) and should not be confused with the ``CONFIGURE_MAXIMUM_DRIVERS`` option. This parameter only -impacts the devFS and thus is only used by ``<rtems/confdefs.h>`` when``CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM`` is specified. +impacts the devFS and thus is only used by ``<rtems/confdefs.h>`` when +``CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM`` is specified. .. COMMENT: === BSP_ZERO_WORKSPACE_AUTOMATICALLY === @@ -3423,13 +3432,14 @@ BSP Recommends RTEMS Workspace be Cleared **DESCRIPTION:** -If ``BSP_ZERO_WORKSPACE_AUTOMATICALLY`` is defined by the BSP and``CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY`` is not defined by the -application, then the workspace will be zeroed automatically. +If ``BSP_ZERO_WORKSPACE_AUTOMATICALLY`` is defined by the BSP and +``CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY`` is not defined by the application, +then the workspace will be zeroed automatically. **NOTES:** -Zeroing memory can add significantly to system boot time. It is not -necessary for RTEMS but is often assumed by support libraries. +Zeroing memory can add significantly to system boot time. It is not necessary +for RTEMS but is often assumed by support libraries. .. COMMENT: === CONFIGURE_BSP_PREREQUISITE_DRIVERS === @@ -3451,25 +3461,24 @@ Specify BSP Prerequisite Drivers **DESCRIPTION:** -``CONFIGURE_BSP_PREREQUISITE_DRIVERS`` is defined if the BSP has device -drivers it needs to include in the Device Driver Table. This should be -defined to the set of device driver entries that will be placed in the -table at the *FRONT* of the Device Driver Table and initialized before -any other drivers *INCLUDING* any application prerequisite drivers. +``CONFIGURE_BSP_PREREQUISITE_DRIVERS`` is defined if the BSP has device drivers +it needs to include in the Device Driver Table. This should be defined to the +set of device driver entries that will be placed in the table at the *FRONT* of +the Device Driver Table and initialized before any other drivers *INCLUDING* +any application prerequisite drivers. **NOTES:** -``CONFIGURE_BSP_PREREQUISITE_DRIVERS`` is typically used by BSPs -to configure common infrastructure such as bus controllers or probe -for devices. +``CONFIGURE_BSP_PREREQUISITE_DRIVERS`` is typically used by BSPs to configure +common infrastructure such as bus controllers or probe for devices. .. COMMENT: === Idle Task Configuration === Idle Task Configuration ======================= -This section defines the IDLE task related configuration parameters -supported by ``<rtems/confdefs.h>``. +This section defines the IDLE task related configuration parameters supported +by ``<rtems/confdefs.h>``. .. COMMENT: === CONFIGURE_IDLE_TASK_BODY === @@ -3491,9 +3500,9 @@ Specify Application Specific Idle Task Body **DESCRIPTION:** -``CONFIGURE_IDLE_TASK_BODY`` is set to the function name corresponding -to the application specific IDLE thread body. If not specified, the -BSP or RTEMS default IDLE thread body will be used. +``CONFIGURE_IDLE_TASK_BODY`` is set to the function name corresponding to the +application specific IDLE thread body. If not specified, the BSP or RTEMS +default IDLE thread body will be used. **NOTES:** @@ -3547,17 +3556,16 @@ Specify Idle Task Performs Application Initialization **DESCRIPTION:** -``CONFIGURE_IDLE_TASK_INITIALIZES_APPLICATION`` is set to -indicate that the user has configured *NO* user initialization tasks -or threads and that the user provided IDLE task will perform application -initialization and then transform itself into an IDLE task. +``CONFIGURE_IDLE_TASK_INITIALIZES_APPLICATION`` is set to indicate that the +user has configured *NO* user initialization tasks or threads and that the user +provided IDLE task will perform application initialization and then transform +itself into an IDLE task. **NOTES:** -If you use this option be careful, the user IDLE task *CANNOT* block -at all during the initialization sequence. Further, once application -initialization is complete, it must make itself preemptible and enter -an IDLE body loop. +If you use this option be careful, the user IDLE task *CANNOT* block at all +during the initialization sequence. Further, once application initialization +is complete, it must make itself preemptible and enter an IDLE body loop. The IDLE task must run at the lowest priority of all tasks in the system. @@ -3567,14 +3575,14 @@ Scheduler Algorithm Configuration ================================= This section defines the configuration parameters related to selecting a -scheduling algorithm for an application. For the schedulers built into -RTEMS, the configuration is straightforward. All that is required is -to define the configuration macro which specifies which scheduler you -want for in your application. The currently available schedulers are: +scheduling algorithm for an application. For the schedulers built into RTEMS, +the configuration is straightforward. All that is required is to define the +configuration macro which specifies which scheduler you want for in your +application. The currently available schedulers are: -The pluggable scheduler interface also enables the user to provide their -own scheduling algorithm. If you choose to do this, you must define -multiple configuration macros. +The pluggable scheduler interface also enables the user to provide their own +scheduling algorithm. If you choose to do this, you must define multiple +configuration macros. .. COMMENT: === CONFIGURE_SCHEDULER_PRIORITY === @@ -3592,22 +3600,22 @@ Use Deterministic Priority Scheduler Defined or undefined. *DEFAULT VALUE:* - This is defined by default. - This is the default scheduler and specifying this - configuration parameter is redundant. + This is defined by default. This is the default scheduler and specifying + this configuration parameter is redundant. **DESCRIPTION:** -The Deterministic Priority Scheduler is the default scheduler in RTEMS -for uni-processor applications and is designed for predictable performance -under the highest loads. It can block or unblock a thread in a constant -amount of time. This scheduler requires a variable amount of memory -based upon the number of priorities configured in the system. +The Deterministic Priority Scheduler is the default scheduler in RTEMS for +uni-processor applications and is designed for predictable performance under +the highest loads. It can block or unblock a thread in a constant amount of +time. This scheduler requires a variable amount of memory based upon the +number of priorities configured in the system. **NOTES:** -This scheduler may be explicitly selected by defining``CONFIGURE_SCHEDULER_PRIORITY`` although this is equivalent to the -default behavior. +This scheduler may be explicitly selected by defining +``CONFIGURE_SCHEDULER_PRIORITY`` although this is equivalent to the default +behavior. .. COMMENT: === CONFIGURE_SCHEDULER_SIMPLE === @@ -3629,15 +3637,16 @@ Use Simple Priority Scheduler **DESCRIPTION:** -When defined, the Simple Priority Scheduler is used at the thread -scheduling algorithm. This is an alternative scheduler in RTEMS. -It is designed to provide the same task scheduling behaviour as the -Deterministic Priority Scheduler while being simpler in implementation -and uses less memory for data management. It maintains a single sorted -list of all ready threads. Thus blocking or unblocking a thread is not -a constant time operation with this scheduler. +When defined, the Simple Priority Scheduler is used at the thread scheduling +algorithm. This is an alternative scheduler in RTEMS. It is designed to +provide the same task scheduling behaviour as the Deterministic Priority +Scheduler while being simpler in implementation and uses less memory for data +management. It maintains a single sorted list of all ready threads. Thus +blocking or unblocking a thread is not a constant time operation with this +scheduler. -This scheduler may be explicitly selected by defining``CONFIGURE_SCHEDULER_SIMPLE``. +This scheduler may be explicitly selected by defining +``CONFIGURE_SCHEDULER_SIMPLE``. **NOTES:** @@ -3665,15 +3674,16 @@ Use Earliest Deadline First Scheduler The Earliest Deadline First Scheduler (EDF) is an alternative scheduler in RTEMS for uni-processor applications. The EDF schedules tasks with dynamic -priorities equal to deadlines. The deadlines are declared using only -Rate Monotonic manager which handles periodic behavior. Period is always -equal to deadline. If a task does not have any deadline declared or the -deadline is cancelled, the task is considered a background task which is -scheduled in case no deadline-driven tasks are ready to run. Moreover, -multiple background tasks are scheduled according their priority assigned -upon initialization. All ready tasks reside in a single ready queue. +priorities equal to deadlines. The deadlines are declared using only Rate +Monotonic manager which handles periodic behavior. Period is always equal to +deadline. If a task does not have any deadline declared or the deadline is +cancelled, the task is considered a background task which is scheduled in case +no deadline-driven tasks are ready to run. Moreover, multiple background tasks +are scheduled according their priority assigned upon initialization. All ready +tasks reside in a single ready queue. -This scheduler may be explicitly selected by defining``CONFIGURE_SCHEDULER_EDF``. +This scheduler may be explicitly selected by defining +``CONFIGURE_SCHEDULER_EDF``. **NOTES:** @@ -3699,13 +3709,14 @@ Use Constant Bandwidth Server Scheduler **DESCRIPTION:** -The Constant Bandwidth Server Scheduler (CBS) is an alternative scheduler -in RTEMS for uni-processor applications. The CBS is a budget aware extension -of EDF scheduler. The goal of this scheduler is to ensure temporal -isolation of tasks. The CBS is equipped with a set of additional rules -and provides with an extensive API. +The Constant Bandwidth Server Scheduler (CBS) is an alternative scheduler in +RTEMS for uni-processor applications. The CBS is a budget aware extension of +EDF scheduler. The goal of this scheduler is to ensure temporal isolation of +tasks. The CBS is equipped with a set of additional rules and provides with an +extensive API. -This scheduler may be explicitly selected by defining``CONFIGURE_SCHEDULER_CBS``. +This scheduler may be explicitly selected by defining +``CONFIGURE_SCHEDULER_CBS``. .. COMMENT: XXX - add cross reference to API chapter @@ -3737,16 +3748,16 @@ The Deterministic Priority SMP Scheduler is derived from the Deterministic Priority Scheduler but is capable of scheduling threads across multiple processors. -In a configuration with SMP enabled at configure time, it may be -explicitly selected by defining ``CONFIGURE_SCHEDULER_PRIORITY_SMP``. +In a configuration with SMP enabled at configure time, it may be explicitly +selected by defining ``CONFIGURE_SCHEDULER_PRIORITY_SMP``. **NOTES:** This scheduler is only available when RTEMS is configured with SMP support enabled. -This scheduler is currently the default in SMP configurations and is -only selected when ``CONFIGURE_SMP_APPLICATION`` is defined. +This scheduler is currently the default in SMP configurations and is only +selected when ``CONFIGURE_SMP_APPLICATION`` is defined. .. COMMENT: === CONFIGURE_SCHEDULER_SIMPLE_SMP === @@ -3768,26 +3779,26 @@ Use Simple SMP Priority Scheduler **DESCRIPTION:** -The Simple SMP Priority Scheduler is derived from the Simple Priority -Scheduler but is capable of scheduling threads across multiple processors. -It is designed to provide the same task scheduling behaviour as the -Deterministic Priority Scheduler while distributing threads across -multiple processors. Being based upon the Simple Priority Scheduler, it also -maintains a single sorted list of all ready threads. Thus blocking or -unblocking a thread is not a constant time operation with this scheduler. +The Simple SMP Priority Scheduler is derived from the Simple Priority Scheduler +but is capable of scheduling threads across multiple processors. It is +designed to provide the same task scheduling behaviour as the Deterministic +Priority Scheduler while distributing threads across multiple processors. +Being based upon the Simple Priority Scheduler, it also maintains a single +sorted list of all ready threads. Thus blocking or unblocking a thread is not +a constant time operation with this scheduler. In addition, when allocating threads to processors, the algorithm is not -constant time. This algorithm was not designed with efficiency as a -primary design goal. Its primary design goal was to provide an SMP-aware -scheduling algorithm that is simple to understand. +constant time. This algorithm was not designed with efficiency as a primary +design goal. Its primary design goal was to provide an SMP-aware scheduling +algorithm that is simple to understand. -In a configuration with SMP enabled at configure time, it may be -explicitly selected by defining ``CONFIGURE_SCHEDULER_SIMPLE_SMP``. +In a configuration with SMP enabled at configure time, it may be explicitly +selected by defining ``CONFIGURE_SCHEDULER_SIMPLE_SMP``. **NOTES:** -This scheduler is only available when RTEMS is configured with SMP -support enabled. +This scheduler is only available when RTEMS is configured with SMP support +enabled. .. COMMENT: === Configuring a Scheduler Name === @@ -3806,17 +3817,18 @@ Configuring a Scheduler Name *DEFAULT VALUE:* The default name is - - ``"UCBS"`` for the Uni-Processor CBS scheduler, - - ``"UEDF"`` for the Uni-Processor EDF scheduler, - - ``"UPD "`` for the Uni-Processor Deterministic Priority scheduler, - - ``"UPS "`` for the Uni-Processor Simple Priority scheduler, - - ``"MPA "`` for the Multi-Processor Priority Affinity scheduler, and - - ``"MPD "`` for the Multi-Processor Deterministic Priority scheduler, and - - ``"MPS "`` for the Multi-Processor Simple Priority scheduler. + - ``"UCBS"`` for the Uni-Processor CBS scheduler, + - ``"UEDF"`` for the Uni-Processor EDF scheduler, + - ``"UPD "`` for the Uni-Processor Deterministic Priority scheduler, + - ``"UPS "`` for the Uni-Processor Simple Priority scheduler, + - ``"MPA "`` for the Multi-Processor Priority Affinity scheduler, and + - ``"MPD "`` for the Multi-Processor Deterministic Priority scheduler, and + - ``"MPS "`` for the Multi-Processor Simple Priority scheduler. **DESCRIPTION:** -Schedulers can be identified via ``rtems_scheduler_ident``. The name of the scheduler is determined by the configuration. +Schedulers can be identified via ``rtems_scheduler_ident``. The name of the +scheduler is determined by the configuration. **NOTES:** @@ -3842,28 +3854,29 @@ Configuring a User Provided Scheduler **DESCRIPTION:** -RTEMS allows the application to provide its own task/thread -scheduling algorithm. In order to do this, one must define``CONFIGURE_SCHEDULER_USER`` to indicate the application provides its -own scheduling algorithm. If ``CONFIGURE_SCHEDULER_USER`` is defined -then the following additional macros must be defined: +RTEMS allows the application to provide its own task/thread scheduling +algorithm. In order to do this, one must define ``CONFIGURE_SCHEDULER_USER`` to +indicate the application provides its own scheduling algorithm. If +``CONFIGURE_SCHEDULER_USER`` is defined then the following additional macros +must be defined: -- ``CONFIGURE_SCHEDULER_CONTEXT`` must be defined to a static definition - of the scheduler context of the user scheduler. +- ``CONFIGURE_SCHEDULER_CONTEXT`` must be defined to a static definition of the + scheduler context of the user scheduler. -- ``CONFIGURE_SCHEDULER_CONTROLS`` must be defined to a scheduler - control initializer for the user scheduler. +- ``CONFIGURE_SCHEDULER_CONTROLS`` must be defined to a scheduler control + initializer for the user scheduler. -- ``CONFIGURE_SCHEDULER_USER_PER_THREAD`` must be defined to the type of - the per-thread information of the user scheduler. +- ``CONFIGURE_SCHEDULER_USER_PER_THREAD`` must be defined to the type of the + per-thread information of the user scheduler. **NOTES:** -At this time, the mechanics and requirements for writing a -new scheduler are evolving and not fully documented. It is -recommended that you look at the existing Deterministic Priority -Scheduler in ``cpukit/score/src/schedulerpriority*.c`` for -guidance. For guidance on the configuration macros, please examine``cpukit/sapi/include/confdefs.h`` for how these are defined for the -Deterministic Priority Scheduler. +At this time, the mechanics and requirements for writing a new scheduler are +evolving and not fully documented. It is recommended that you look at the +existing Deterministic Priority Scheduler in +``cpukit/score/src/schedulerpriority*.c`` for guidance. For guidance on the +configuration macros, please examine ``cpukit/sapi/include/confdefs.h`` for how +these are defined for the Deterministic Priority Scheduler. .. COMMENT: === Configuring Clustered Schedulers === @@ -3881,8 +3894,8 @@ and thus avoid expensive cache synchronization traffic. We have clustered scheduling in case the set of processors of a system is partitioned into non-empty pairwise-disjoint subsets. These subsets are called clusters. Clusters with a cardinality of one are partitions. Each cluster is -owned by exactly one scheduler instance. In order to use clustered -scheduling the application designer has to answer two questions. +owned by exactly one scheduler instance. In order to use clustered scheduling +the application designer has to answer two questions. # How is the set of processors partitioned into clusters? @@ -3902,9 +3915,9 @@ following defines This is necessary to calculate the per-thread overhead introduced by the schedulers. After these definitions the configuration file must ``#include -<rtems/scheduler.h>`` to have access to scheduler specific configuration macros. -Each scheduler needs a context to store state information at run-time. To -provide a context for each scheduler is the next step. Use the following +<rtems/scheduler.h>`` to have access to scheduler specific configuration +macros. Each scheduler needs a context to store state information at run-time. +To provide a context for each scheduler is the next step. Use the following macros to create scheduler contexts - ``RTEMS_SCHEDULER_CONTEXT_PRIORITY_SMP(name, prio_count)``, @@ -3913,11 +3926,11 @@ macros to create scheduler contexts - ``RTEMS_SCHEDULER_CONTEXT_PRIORITY_AFFINITY_SMP(name, prio_count)``. -The ``name`` parameter is used as part of a designator for a global -variable, so the usual C/C++ designator rules apply. Additional parameters are -scheduler specific. The schedulers are registered in the system via the -scheduler table. To create the scheduler table define``CONFIGURE_SCHEDULER_CONTROLS`` to a list of the following scheduler -control initializers +The ``name`` parameter is used as part of a designator for a global variable, +so the usual C/C++ designator rules apply. Additional parameters are scheduler +specific. The schedulers are registered in the system via the scheduler table. +To create the scheduler table define ``CONFIGURE_SCHEDULER_CONTROLS`` to a list +of the following scheduler control initializers - ``RTEMS_SCHEDULER_CONTROL_PRIORITY_SMP(name, obj_name)``, @@ -3925,23 +3938,24 @@ control initializers - ``RTEMS_SCHEDULER_CONTROL_PRIORITY_AFFINITY_SMP(name, obj_name)``. -The ``name`` parameter must correspond to the parameter defining the -scheduler context. The ``obj_name`` determines the scheduler object name -and can be used in ``rtems_scheduler_ident()`` to get the scheduler object -identifier. - -The last step is to define which processor uses which scheduler. -For this purpose a scheduler assignment table must be defined. The entry count -of this table must be equal to the configured maximum processors -(``CONFIGURE_SMP_MAXIMUM_PROCESSORS``). A processor assignment to a -scheduler can be optional or mandatory. The boot processor must have a -scheduler assigned. In case the system needs more mandatory processors than -available then a fatal run-time error will occur. To specify the scheduler -assignments define ``CONFIGURE_SMP_SCHEDULER_ASSIGNMENTS`` to a list of``RTEMS_SCHEDULER_ASSIGN(index, attr)`` and``RTEMS_SCHEDULER_ASSIGN_NO_SCHEDULER`` macros. The ``index`` parameter -must be a valid index into the scheduler table. The ``attr`` parameter -defines the scheduler assignment attributes. By default a scheduler assignment -to a processor is optional. For the scheduler assignment attribute use one of -the mutually exclusive variants +The ``name`` parameter must correspond to the parameter defining the scheduler +context. The ``obj_name`` determines the scheduler object name and can be used +in ``rtems_scheduler_ident()`` to get the scheduler object identifier. + +The last step is to define which processor uses which scheduler. For this +purpose a scheduler assignment table must be defined. The entry count of this +table must be equal to the configured maximum processors +(``CONFIGURE_SMP_MAXIMUM_PROCESSORS``). A processor assignment to a scheduler +can be optional or mandatory. The boot processor must have a scheduler +assigned. In case the system needs more mandatory processors than available +then a fatal run-time error will occur. To specify the scheduler assignments +define ``CONFIGURE_SMP_SCHEDULER_ASSIGNMENTS`` to a list of +``RTEMS_SCHEDULER_ASSIGN(index, attr)`` and +``RTEMS_SCHEDULER_ASSIGN_NO_SCHEDULER`` macros. The ``index`` parameter must +be a valid index into the scheduler table. The ``attr`` parameter defines the +scheduler assignment attributes. By default a scheduler assignment to a +processor is optional. For the scheduler assignment attribute use one of the +mutually exclusive variants - ``RTEMS_SCHEDULER_ASSIGN_DEFAULT``, @@ -3951,26 +3965,28 @@ the mutually exclusive variants **ERRORS:** -In case one of the scheduler indices in``CONFIGURE_SMP_SCHEDULER_ASSIGNMENTS`` is invalid a link-time error will -occur with an undefined reference to ``RTEMS_SCHEDULER_INVALID_INDEX``. +In case one of the scheduler indices in``CONFIGURE_SMP_SCHEDULER_ASSIGNMENTS`` +is invalid a link-time error will occur with an undefined reference to +``RTEMS_SCHEDULER_INVALID_INDEX``. -Some fatal errors may occur in case of scheduler configuration inconsistencies or a lack -of processors on the system. The fatal source is``RTEMS_FATAL_SOURCE_SMP``. None of the errors is internal. +Some fatal errors may occur in case of scheduler configuration inconsistencies +or a lack of processors on the system. The fatal source is +``RTEMS_FATAL_SOURCE_SMP``. None of the errors is internal. -- ``SMP_FATAL_BOOT_PROCESSOR_NOT_ASSIGNED_TO_SCHEDULER`` - the boot - processor must have a scheduler assigned. +- ``SMP_FATAL_BOOT_PROCESSOR_NOT_ASSIGNED_TO_SCHEDULER`` - the boot processor + must have a scheduler assigned. -- ``SMP_FATAL_MANDATORY_PROCESSOR_NOT_PRESENT`` - there exists a - mandatory processor beyond the range of physically or virtually available - processors. The processor demand must be reduced for this system. +- ``SMP_FATAL_MANDATORY_PROCESSOR_NOT_PRESENT`` - there exists a mandatory + processor beyond the range of physically or virtually available processors. + The processor demand must be reduced for this system. -- ``SMP_FATAL_START_OF_MANDATORY_PROCESSOR_FAILED`` - the start of a - mandatory processor failed during system initialization. The system may not - have this processor at all or it could be a problem with a boot loader for - example. Check the ``CONFIGURE_SMP_SCHEDULER_ASSIGNMENTS`` definition. +- ``SMP_FATAL_START_OF_MANDATORY_PROCESSOR_FAILED`` - the start of a mandatory + processor failed during system initialization. The system may not have this + processor at all or it could be a problem with a boot loader for example. + Check the ``CONFIGURE_SMP_SCHEDULER_ASSIGNMENTS`` definition. -- ``SMP_FATAL_MULTITASKING_START_ON_UNASSIGNED_PROCESSOR`` - it is not - allowed to start multitasking on a processor with no scheduler assigned. +- ``SMP_FATAL_MULTITASKING_START_ON_UNASSIGNED_PROCESSOR`` - it is not allowed + to start multitasking on a processor with no scheduler assigned. **EXAMPLE:** @@ -3985,20 +4001,20 @@ processing operations. The processors managed by RTEMS use two Deterministic Priority scheduler instances capable of dealing with 256 priority levels. The scheduler with -index zero has the name ``"IO "``. The scheduler with index one has the -name ``"WORK"``. The scheduler assignments of the first, third and fourth -processor are mandatory, so the system must have at least four processors, -otherwise a fatal run-time error will occur during system startup. The -processor assignments for the fifth up to the eighth processor are optional so -that the same application can be used for the normal and high-performance -product lines. The second processor has no scheduler assigned and runs Linux. -A hypervisor will ensure that the two systems cannot interfere in an -undesirable way. +index zero has the name ``"IO "``. The scheduler with index one has the name +``"WORK"``. The scheduler assignments of the first, third and fourth processor +are mandatory, so the system must have at least four processors, otherwise a +fatal run-time error will occur during system startup. The processor +assignments for the fifth up to the eighth processor are optional so that the +same application can be used for the normal and high-performance product lines. +The second processor has no scheduler assigned and runs Linux. A hypervisor +will ensure that the two systems cannot interfere in an undesirable way. + .. code:: c #define CONFIGURE_SMP_MAXIMUM_PROCESSORS 8 #define CONFIGURE_MAXIMUM_PRIORITY 255 - /* Make the scheduler algorithm available \*/ + /* Make the scheduler algorithm available */ #define CONFIGURE_SCHEDULER_PRIORITY_SMP #include <rtems/scheduler.h> /* Create contexts for the two scheduler instances \*/ @@ -4006,24 +4022,24 @@ undesirable way. RTEMS_SCHEDULER_CONTEXT_PRIORITY_SMP(work, CONFIGURE_MAXIMUM_PRIORITY + 1); /* Define the scheduler table \*/ #define CONFIGURE_SCHEDULER_CONTROLS \\ - RTEMS_SCHEDULER_CONTROL_PRIORITY_SMP( \\ - io, \\ - rtems_build_name('I', 'O', ' ', ' ') \\ - ), \\ - RTEMS_SCHEDULER_CONTROL_PRIORITY_SMP( \\ - work, \\ - rtems_build_name('W', 'O', 'R', 'K') \\ - ) - /* Define the processor to scheduler assignments \*/ - #define CONFIGURE_SMP_SCHEDULER_ASSIGNMENTS \\ - RTEMS_SCHEDULER_ASSIGN(0, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_MANDATORY), \\ - RTEMS_SCHEDULER_ASSIGN_NO_SCHEDULER, \\ - RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_MANDATORY), \\ - RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_MANDATORY), \\ - RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_OPTIONAL), \\ - RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_OPTIONAL), \\ - RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_OPTIONAL), \\ - RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_OPTIONAL) + RTEMS_SCHEDULER_CONTROL_PRIORITY_SMP( \ + io, \ + rtems_build_name('I', 'O', ' ', ' ') \ + ), \ + RTEMS_SCHEDULER_CONTROL_PRIORITY_SMP( \ + work, \ + rtems_build_name('W', 'O', 'R', 'K') \ + ) + /* Define the processor to scheduler assignments */ + #define CONFIGURE_SMP_SCHEDULER_ASSIGNMENTS \ + RTEMS_SCHEDULER_ASSIGN(0, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_MANDATORY), \ + RTEMS_SCHEDULER_ASSIGN_NO_SCHEDULER, \ + RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_MANDATORY), \ + RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_MANDATORY), \ + RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_OPTIONAL), \ + RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_OPTIONAL), \ + RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_OPTIONAL), \ + RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_OPTIONAL) .. COMMENT: === SMP Specific Configuration Parameters === @@ -4084,8 +4100,8 @@ Specify Maximum Processors in SMP System **DESCRIPTION:** -``CONFIGURE_SMP_MAXIMUM_PROCESSORS`` must be set to the number of -processors in the SMP configuration. +``CONFIGURE_SMP_MAXIMUM_PROCESSORS`` must be set to the number of processors in +the SMP configuration. **NOTES:** @@ -4097,11 +4113,10 @@ ignored. This configuration define is ignored on uni-processor configurations. Device Driver Table =================== -This section defines the configuration parameters related -to the automatic generation of a Device Driver Table. As``<rtems/confdefs.h>`` only is aware of a small set of -standard device drivers, the generated Device Driver -Table is suitable for simple applications with no -custom device drivers. +This section defines the configuration parameters related to the automatic +generation of a Device Driver Table. As ``<rtems/confdefs.h>`` only is aware +of a small set of standard device drivers, the generated Device Driver Table is +suitable for simple applications with no custom device drivers. Note that network device drivers are not configured in the Device Driver Table. @@ -4127,15 +4142,16 @@ Specifying the Maximum Number of Device Drivers **DESCRIPTION:** -``CONFIGURE_MAXIMUM_DRIVERS`` is defined as the number of device -drivers per node. +``CONFIGURE_MAXIMUM_DRIVERS`` is defined as the number of device drivers per +node. **NOTES:** If the application will dynamically install device drivers, then this -configuration parameter must be larger than the number of statically -configured device drivers. Drivers configured using the``CONFIGURE_APPLICATIONS_NEEDS_XXX_DRIVER`` configuration parameters -are statically installed. +configuration parameter must be larger than the number of statically configured +device drivers. Drivers configured using the +``CONFIGURE_APPLICATIONS_NEEDS_XXX_DRIVER`` configuration parameters are +statically installed. .. COMMENT: === CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER === @@ -4157,16 +4173,16 @@ Enable Console Device Driver **DESCRIPTION:** -``CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER`` is defined if the -application wishes to include the Console Device Driver. +``CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER`` is defined if the application +wishes to include the Console Device Driver. **NOTES:** -This device driver is responsible for providing standard input and output -using */dev/console*. +This device driver is responsible for providing standard input and output using +*/dev/console*. -BSPs should be constructed in a manner that allows ``printk()`` -to work properly without the need for the console driver to be configured. +BSPs should be constructed in a manner that allows ``printk()`` to work +properly without the need for the console driver to be configured. .. COMMENT: === CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER === @@ -4188,17 +4204,17 @@ Enable Clock Driver **DESCRIPTION:** -``CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER`` is defined if the -application wishes to include the Clock Device Driver. +``CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER`` is defined if the application +wishes to include the Clock Device Driver. **NOTES:** -This device driver is responsible for providing a regular -interrupt which invokes the ``rtems_clock_tick`` directive. +This device driver is responsible for providing a regular interrupt which +invokes the ``rtems_clock_tick`` directive. -If neither the Clock Driver not Benchmark Timer is enabled and -the configuration parameter``CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER`` is not defined, -then a compile time error will occur. +If neither the Clock Driver not Benchmark Timer is enabled and the +configuration parameter ``CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER`` is +not defined, then a compile time error will occur. .. COMMENT: === CONFIGURE_APPLICATION_NEEDS_TIMER_DRIVER === @@ -4226,9 +4242,9 @@ used to benchmark execution times by the RTEMS Timing Test Suites. **NOTES:** -If neither the Clock Driver not Benchmark Timer is enabled and -the configuration parameter``CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER`` is not defined, -then a compile time error will occur. +If neither the Clock Driver not Benchmark Timer is enabled and the +configuration parameter ``CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER`` is +not defined, then a compile time error will occur. .. COMMENT: === CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER === @@ -4250,16 +4266,16 @@ Specify Clock and Benchmark Timer Drivers Are Not Needed **DESCRIPTION:** -``CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER`` is defined when -the application does *NOT* want the Clock Device Driver and is *NOT* -using the Timer Driver. The inclusion or exclusion of the Clock Driver -must be explicit in user applications. +``CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER`` is defined when the +application does *NOT* want the Clock Device Driver and is *NOT* using the +Timer Driver. The inclusion or exclusion of the Clock Driver must be explicit +in user applications. **NOTES:** -This configuration parameter is intended to prevent the common user error -of using the Hello World example as the baseline for an application and -leaving out a clock tick source. +This configuration parameter is intended to prevent the common user error of +using the Hello World example as the baseline for an application and leaving +out a clock tick source. .. COMMENT: === CONFIGURE_APPLICATION_NEEDS_RTC_DRIVER === @@ -4281,16 +4297,16 @@ Enable Real-Time Clock Driver **DESCRIPTION:** -``CONFIGURE_APPLICATION_NEEDS_RTC_DRIVER`` is defined if the -application wishes to include the Real-Time Clock Driver. +``CONFIGURE_APPLICATION_NEEDS_RTC_DRIVER`` is defined if the application wishes +to include the Real-Time Clock Driver. **NOTES:** -Most BSPs do not include support for a real-time clock. This is because -many boards do not include the required hardware. +Most BSPs do not include support for a real-time clock. This is because many +boards do not include the required hardware. -If this is defined and the BSP does not have this device driver, then -the user will get a link time error for an undefined symbol. +If this is defined and the BSP does not have this device driver, then the user +will get a link time error for an undefined symbol. .. COMMENT: === CONFIGURE_APPLICATION_NEEDS_WATCHDOG_DRIVER === @@ -4312,16 +4328,16 @@ Enable the Watchdog Device Driver **DESCRIPTION:** -``CONFIGURE_APPLICATION_NEEDS_WATCHDOG_DRIVER`` -is defined if the application wishes to include the Watchdog Driver. +``CONFIGURE_APPLICATION_NEEDS_WATCHDOG_DRIVER`` is defined if the application +wishes to include the Watchdog Driver. **NOTES:** -Most BSPs do not include support for a watchdog device driver. This is -because many boards do not include the required hardware. +Most BSPs do not include support for a watchdog device driver. This is because +many boards do not include the required hardware. -If this is defined and the BSP does not have this device driver, then -the user will get a link time error for an undefined symbol. +If this is defined and the BSP does not have this device driver, then the user +will get a link time error for an undefined symbol. .. COMMENT: === CONFIGURE_APPLICATION_NEEDS_FRAME_BUFFER_DRIVER === @@ -4343,16 +4359,16 @@ Enable the Graphics Frame Buffer Device Driver **DESCRIPTION:** -``CONFIGURE_APPLICATION_NEEDS_FRAME_BUFFER_DRIVER`` is defined -if the application wishes to include the BSP's Frame Buffer Device Driver. +``CONFIGURE_APPLICATION_NEEDS_FRAME_BUFFER_DRIVER`` is defined if the +application wishes to include the BSP's Frame Buffer Device Driver. **NOTES:** Most BSPs do not include support for a Frame Buffer Device Driver. This is because many boards do not include the required hardware. -If this is defined and the BSP does not have this device driver, then -the user will get a link time error for an undefined symbol. +If this is defined and the BSP does not have this device driver, then the user +will get a link time error for an undefined symbol. .. COMMENT: === CONFIGURE_APPLICATION_NEEDS_STUB_DRIVER === @@ -4374,13 +4390,13 @@ Enable Stub Device Driver **DESCRIPTION:** -``CONFIGURE_APPLICATION_NEEDS_STUB_DRIVER`` is defined if the -application wishes to include the Stub Device Driver. +``CONFIGURE_APPLICATION_NEEDS_STUB_DRIVER`` is defined if the application +wishes to include the Stub Device Driver. **NOTES:** -This device driver simply provides entry points that return successful -and is primarily a test fixture. It is supported by all BSPs. +This device driver simply provides entry points that return successful and is +primarily a test fixture. It is supported by all BSPs. .. COMMENT: === CONFIGURE_APPLICATION_PREREQUISITE_DRIVERS === @@ -4402,20 +4418,19 @@ Specify Application Prerequisite Device Drivers **DESCRIPTION:** -``CONFIGURE_APPLICATION_PREREQUISITE_DRIVERS`` is defined if the -application has device drivers it needs to include in the Device Driver -Table. This should be defined to the set of device driver entries that -will be placed in the table at the *FRONT* of the Device Driver Table -and initialized before any other drivers *EXCEPT* any BSP prerequisite -drivers. +``CONFIGURE_APPLICATION_PREREQUISITE_DRIVERS`` is defined if the application +has device drivers it needs to include in the Device Driver Table. This should +be defined to the set of device driver entries that will be placed in the table +at the *FRONT* of the Device Driver Table and initialized before any other +drivers *EXCEPT* any BSP prerequisite drivers. **NOTES:** -In some cases, it is used by System On Chip BSPs to support peripheral -buses beyond those normally found on the System On Chip. For example, -this is used by one RTEMS system which has implemented a SPARC/ERC32 -based board with VMEBus. The VMEBus Controller initialization is performed -by a device driver configured via this configuration parameter. +In some cases, it is used by System On Chip BSPs to support peripheral buses +beyond those normally found on the System On Chip. For example, this is used by +one RTEMS system which has implemented a SPARC/ERC32 based board with +VMEBus. The VMEBus Controller initialization is performed by a device driver +configured via this configuration parameter. .. COMMENT: XXX Add example @@ -4439,10 +4454,10 @@ Specify Extra Application Device Drivers **DESCRIPTION:** -``CONFIGURE_APPLICATION_EXTRA_DRIVERS`` is defined if the -application has device drivers it needs to include in the Device Driver -Table. This should be defined to the set of device driver entries that -will be placed in the table at the *END* of the Device Driver Table. +``CONFIGURE_APPLICATION_EXTRA_DRIVERS`` is defined if the application has +device drivers it needs to include in the Device Driver Table. This should be +defined to the set of device driver entries that will be placed in the table at +the *END* of the Device Driver Table. **NOTES:** @@ -4469,8 +4484,7 @@ Enable /dev/null Device Driver **DESCRIPTION:** -This configuration variable is specified to enable */dev/null* -device driver. +This configuration variable is specified to enable ``/dev/null`` device driver. **NOTES:** @@ -4497,8 +4511,7 @@ Enable /dev/zero Device Driver **DESCRIPTION:** -This configuration variable is specified to enable */dev/zero* -device driver. +This configuration variable is specified to enable ``/dev/zero`` device driver. **NOTES:** @@ -4520,17 +4533,18 @@ Specifying Application Defined Device Driver Table Defined or undefined. *DEFAULT VALUE:* - This is not defined by default, indicating the ``<rtems/confdefs.h>`` - is providing the device driver table. + This is not defined by default, indicating the ``<rtems/confdefs.h>`` is + providing the device driver table. **DESCRIPTION:** -``CONFIGURE_HAS_OWN_DEVICE_DRIVER_TABLE`` is defined if the application -wishes to provide their own Device Driver Table. +``CONFIGURE_HAS_OWN_DEVICE_DRIVER_TABLE`` is defined if the application wishes +to provide their own Device Driver Table. -The table must be an array of ``rtems_driver_address_table`` entries named``_IO_Driver_address_table``. The application must also provide a const -variable ``_IO_Number_of_drivers`` of type ``size_t`` indicating the -number of entries in the ``_IO_Driver_address_table``. +The table must be an array of ``rtems_driver_address_table`` entries named`` +_IO_Driver_address_table``. The application must also provide a const variable +``_IO_Number_of_drivers`` of type ``size_t`` indicating the number of entries +in the ``_IO_Driver_address_table``. **NOTES:** @@ -4542,11 +4556,12 @@ Multiprocessing Configuration ============================= This section defines the multiprocessing related system configuration -parameters supported by ``<rtems/confdefs.h>``. They are only used -if the Multiprocessing Support (distinct from the SMP support) is enabled -at configure time using the ``--enable-multiprocessing`` option. +parameters supported by ``<rtems/confdefs.h>``. They are only used if the +Multiprocessing Support (distinct from the SMP support) is enabled at configure +time using the ``--enable-multiprocessing`` option. -Additionally, this class of Configuration Constants are only applicable if``CONFIGURE_MP_APPLICATION`` is defined. +Additionally, this class of Configuration Constants are only applicable if +``CONFIGURE_MP_APPLICATION`` is defined. .. COMMENT: === CONFIGURE_MP_APPLICATION === @@ -4568,14 +4583,14 @@ Specify Application Will Use Multiprocessing **DESCRIPTION:** -This configuration parameter must be defined to indicate -that the application intends to be part of a multiprocessing -configuration. Additional configuration parameters are assumed to be -provided. +This configuration parameter must be defined to indicate that the application +intends to be part of a multiprocessing configuration. Additional configuration +parameters are assumed to be provided. **NOTES:** -This has no impact unless RTEMS was configured and built using the``--enable-multiprocessing`` option. +This has no impact unless RTEMS was configured and built using the +``--enable-multiprocessing`` option. .. COMMENT: === CONFIGURE_MP_NODE_NUMBER === @@ -4593,20 +4608,20 @@ Configure Node Number in Multiprocessor Configuration Positive. *DEFAULT VALUE:* - The default value is ``NODE_NUMBER``, which is assumed to be - set by the compilation environment. + The default value is ``NODE_NUMBER``, which is assumed to be set by the + compilation environment. **DESCRIPTION:** -``CONFIGURE_MP_NODE_NUMBER`` is the node number of -this node in a multiprocessor system. +``CONFIGURE_MP_NODE_NUMBER`` is the node number of this node in a +multiprocessor system. **NOTES:** -In the RTEMS Multiprocessing Test Suite, the node number is derived from -the Makefile variable ``NODE_NUMBER``. The same code is compiled with -the ``NODE_NUMBER`` set to different values. The test programs behave -differently based upon their node number. +In the RTEMS Multiprocessing Test Suite, the node number is derived from the +Makefile variable ``NODE_NUMBER``. The same code is compiled with the +``NODE_NUMBER`` set to different values. The test programs behave differently +based upon their node number. .. COMMENT: === CONFIGURE_MP_MAXIMUM_NODES === @@ -4655,13 +4670,13 @@ Configure Maximum Global Objects in Multiprocessor Configuration **DESCRIPTION:** -``CONFIGURE_MP_MAXIMUM_GLOBAL_OBJECTS`` is the maximum number of -concurrently active global objects in a multiprocessor system. +``CONFIGURE_MP_MAXIMUM_GLOBAL_OBJECTS`` is the maximum number of concurrently +active global objects in a multiprocessor system. **NOTES:** -This value corresponds to the total number of objects which can be -created with the ``RTEMS_GLOBAL`` attribute. +This value corresponds to the total number of objects which can be created with +the ``RTEMS_GLOBAL`` attribute. .. COMMENT: === CONFIGURE_MP_MAXIMUM_PROXIES === @@ -4689,8 +4704,8 @@ active thread/task proxies on this node in a multiprocessor system. **NOTES:** Since a proxy is used to represent a remote task/thread which is blocking on -this node. This configuration parameter reflects the maximum number of -remote tasks/threads which can be blocked on objects on this node. +this node. This configuration parameter reflects the maximum number of remote +tasks/threads which can be blocked on objects on this node. .. COMMENT: XXX - add xref to proxy discussion in MP chapter @@ -4714,14 +4729,14 @@ Configure MPCI in Multiprocessor Configuration **DESCRIPTION:** -``CONFIGURE_MP_MPCI_TABLE_POINTER`` is the pointer to the -MPCI Configuration Table. The default value of this field is``&MPCI_table``. +``CONFIGURE_MP_MPCI_TABLE_POINTER`` is the pointer to the MPCI Configuration +Table. The default value of this field is``&MPCI_table``. **NOTES:** -RTEMS provides a Shared Memory MPCI Device Driver which can be used on -any Multiprocessor System assuming the BSP provides the proper set of -supporting methods. +RTEMS provides a Shared Memory MPCI Device Driver which can be used on any +Multiprocessor System assuming the BSP provides the proper set of supporting +methods. .. COMMENT: === CONFIGURE_HAS_OWN_MULTIPROCESSING_TABLE === @@ -4743,31 +4758,32 @@ Do Not Generate Multiprocessor Configuration Table **DESCRIPTION:** -``CONFIGURE_HAS_OWN_MULTIPROCESSING_TABLE`` is defined if the -application wishes to provide their own Multiprocessing Configuration -Table. The generated table is named ``Multiprocessing_configuration``. +``CONFIGURE_HAS_OWN_MULTIPROCESSING_TABLE`` is defined if the application +wishes to provide their own Multiprocessing Configuration Table. The generated +table is named ``Multiprocessing_configuration``. **NOTES:** -This is a configuration parameter which is very unlikely to be used by -an application. If you find yourself wanting to use it in an application, -please reconsider and discuss this on the RTEMS Users mailing list. +This is a configuration parameter which is very unlikely to be used by an +application. If you find yourself wanting to use it in an application, please +reconsider and discuss this on the RTEMS Users mailing list. .. COMMENT: === Ada Tasks === Ada Tasks ========= -This section defines the system configuration parameters supported -by ``<rtems/confdefs.h>`` related to configuring RTEMS to support -a task using Ada tasking with GNAT/RTEMS. +This section defines the system configuration parameters supported by +``<rtems/confdefs.h>`` related to configuring RTEMS to support a task using Ada +tasking with GNAT/RTEMS. -These configuration parameters are only available when RTEMS is built with -the ``--enable-ada`` configure option and the application specifies``CONFIGURE_GNAT_RTEMS``. +These configuration parameters are only available when RTEMS is built with the +``--enable-ada`` configure option and the application specifies +``CONFIGURE_GNAT_RTEMS``. -Additionally RTEMS includes an Ada language binding to the Classic -API which has a test suite. This test suite is enabled only when``--enable-tests`` and ``--enable-expada`` are specified on the -configure command. +Additionally RTEMS includes an Ada language binding to the Classic API which +has a test suite. This test suite is enabled only when``--enable-tests`` and +``--enable-expada`` are specified on the configure command. .. COMMENT: === CONFIGURE_GNAT_RTEMS === @@ -4789,14 +4805,14 @@ Specify Application Includes Ada Code **DESCRIPTION:** -``CONFIGURE_GNAT_RTEMS`` is defined to inform RTEMS that the GNAT -Ada run-time is to be used by the application. +``CONFIGURE_GNAT_RTEMS`` is defined to inform RTEMS that the GNAT Ada run-time +is to be used by the application. **NOTES:** -This configuration parameter is critical as it makes``<rtems/confdefs.h>`` configure the resources (POSIX API Threads, -Mutexes, Condition Variables, and Keys) used implicitly by the GNAT -run-time. +This configuration parameter is critical as it makes``<rtems/confdefs.h>`` +configure the resources (POSIX API Threads, Mutexes, Condition Variables, and +Keys) used implicitly by the GNAT run-time. .. COMMENT: === CONFIGURE_MAXIMUM_ADA_TASKS === @@ -4814,13 +4830,13 @@ Specify the Maximum Number of Ada Tasks. Undefined or positive. *DEFAULT VALUE:* - If ``CONFIGURE_GNAT_RTEMS`` is defined, then the - default value is 20, otherwise the default value is 0. + If ``CONFIGURE_GNAT_RTEMS`` is defined, then the default value is 20, + otherwise the default value is 0. **DESCRIPTION:** -``CONFIGURE_MAXIMUM_ADA_TASKS`` is the number of Ada tasks that can -be concurrently active in the system. +``CONFIGURE_MAXIMUM_ADA_TASKS`` is the number of Ada tasks that can be +concurrently active in the system. **NOTES:** @@ -4846,10 +4862,9 @@ Specify the Maximum Fake Ada Tasks **DESCRIPTION:** -``CONFIGURE_MAXIMUM_FAKE_ADA_TASKS`` is the number of *fake* Ada tasks -that can be concurrently active in the system. A *fake* Ada task is -a non-Ada task that makes calls back into Ada code and thus implicitly -uses the Ada run-time. +``CONFIGURE_MAXIMUM_FAKE_ADA_TASKS`` is the number of *fake* Ada tasks that can +be concurrently active in the system. A *fake* Ada task is a non-Ada task that +makes calls back into Ada code and thus implicitly uses the Ada run-time. **NOTES:** @@ -4860,51 +4875,53 @@ None. PCI Library =========== -This section defines the system configuration parameters supported -by ``rtems/confdefs.h`` related to configuring the PCI Library -for RTEMS. - -The PCI Library startup behaviour can be configured in four different -ways depending on how ``CONFIGURE_PCI_CONFIG_LIB`` is defined: - -- .. index:: PCI_LIB_AUTO - - ``PCI_LIB_AUTO`` is used to enable the PCI auto configuration - software. PCI will be automatically probed, PCI buses enumerated, all - devices and bridges will be initialized using Plug & Play software - routines. The PCI device tree will be populated based on the PCI devices - found in the system, PCI devices will be configured by allocating address - region resources automatically in PCI space according to the BSP or host - bridge driver set up. - -- .. index:: PCI_LIB_READ - - ``PCI_LIB_READ`` is used to enable the PCI read configuration - software. The current PCI configuration is read to create the RAM - representation (the PCI device tree) of the PCI devices present. PCI devices - are assumed to already have been initialized and PCI buses enumerated, it is - therefore required that a BIOS or a boot loader has set up configuration space - prior to booting into RTEMS. - -- .. index:: PCI_LIB_STATIC - - ``PCI_LIB_STATIC`` is used to enable the PCI static configuration - software. The user provides a PCI tree with information how all PCI devices - are to be configured at compile time by linking in a custom``struct pci_bus pci_hb`` tree. The static PCI library will not probe PCI - for devices, instead it will assume that all devices defined by the user are - present, it will enumerate the PCI buses and configure all PCI devices in - static configuration accordingly. Since probe and allocation software is not - needed the startup is faster, has smaller footprint and does not require - dynamic memory allocation. - -- .. index:: PCI_LIB_PERIPHERAL - - ``PCI_LIB_PERIPHERAL`` is used to enable the PCI peripheral - configuration. It is similar to ``PCI_LIB_STATIC``, but it will never write - the configuration to the PCI devices since PCI peripherals are not allowed to - access PCI configuration space. - -Note that selecting PCI_LIB_STATIC or PCI_LIB_PERIPHERAL but not defining``pci_hb`` will reuslt in link errors. Note also that in these modes +This section defines the system configuration parameters supported by +``rtems/confdefs.h`` related to configuring the PCI Library for RTEMS. + +The PCI Library startup behaviour can be configured in four different ways +depending on how ``CONFIGURE_PCI_CONFIG_LIB`` is defined: + +.. index:: PCI_LIB_AUTO + +``PCI_LIB_AUTO`` + Used to enable the PCI auto configuration software. PCI will be automatically + probed, PCI buses enumerated, all devices and bridges will be initialized + using Plug & Play software routines. The PCI device tree will be populated + based on the PCI devices found in the system, PCI devices will be configured + by allocating address region resources automatically in PCI space according + to the BSP or host bridge driver set up. + +.. index:: PCI_LIB_READ + +``PCI_LIB_READ`` + Used to enable the PCI read configuration software. The current PCI + configuration is read to create the RAM representation (the PCI device tree) + of the PCI devices present. PCI devices are assumed to already have been + initialized and PCI buses enumerated, it is therefore required that a BIOS or + a boot loader has set up configuration space prior to booting into RTEMS. + +.. index:: PCI_LIB_STATIC + +``PCI_LIB_STATIC`` + Used to enable the PCI static configuration software. The user provides a PCI + tree with information how all PCI devices are to be configured at compile + time by linking in a custom ``struct pci_bus pci_hb`` tree. The static PCI + library will not probe PCI for devices, instead it will assume that all + devices defined by the user are present, it will enumerate the PCI buses and + configure all PCI devices in static configuration accordingly. Since probe + and allocation software is not needed the startup is faster, has smaller + footprint and does not require dynamic memory allocation. + +.. index:: PCI_LIB_PERIPHERAL + +``PCI_LIB_PERIPHERAL`` + Used to enable the PCI peripheral configuration. It is similar to + ``PCI_LIB_STATIC``, but it will never write the configuration to the PCI + devices since PCI peripherals are not allowed to access PCI configuration + space. + +Note that selecting ``PCI_LIB_STATIC`` or ``PCI_LIB_PERIPHERAL`` but not +defining ``pci_hb`` will reuslt in link errors. Note also that in these modes Plug & Play is not performed. .. COMMENT: === Go Tasks === @@ -4932,8 +4949,8 @@ Specify Application Includes Go Code **DESCRIPTION:** -``CONFIGURE_ENABLE_GO`` is defined to inform RTEMS that the Go -run-time is to be used by the application. +``CONFIGURE_ENABLE_GO`` is defined to inform RTEMS that the Go run-time is to +be used by the application. **NOTES:** @@ -4959,8 +4976,8 @@ Specify the maximum number of Go routines **DESCRIPTION:** -``CONFIGURE_MAXIMUM_GOROUTINES`` is defined to specify the maximum number of -Go routines. +``CONFIGURE_MAXIMUM_GOROUTINES`` is defined to specify the maximum number of Go +routines. **NOTES:** @@ -4986,8 +5003,8 @@ Specify the maximum number of Go Channels **DESCRIPTION:** -``CONFIGURE_MAXIMUM_GO_CHANNELS`` is defined to specify the maximum number -of Go channels. +``CONFIGURE_MAXIMUM_GO_CHANNELS`` is defined to specify the maximum number of +Go channels. **NOTES:** @@ -4998,19 +5015,12 @@ The Go language support is experimental Configuration Data Structures ============================= -It is recommended that applications be configured using``<rtems/confdefs.h>`` as it is simpler and insulates applications -from changes in the underlying data structures. However, it is sometimes -important to understand the data structures that are automatically filled -in by the configuration parameters. This section describes the primary -configuration data structures. - -If the user wishes to see the details of a particular data structure, -they are are advised to look at the source code. After all, that is one -of the advantages of RTEMS. - -.. COMMENT: COPYRIGHT (c) 1988-2007. - -.. COMMENT: On-Line Applications Research Corporation (OAR). - -.. COMMENT: All rights reserved. +It is recommended that applications be configured using ``<rtems/confdefs.h>`` +as it is simpler and insulates applications from changes in the underlying data +structures. However, it is sometimes important to understand the data +structures that are automatically filled in by the configuration parameters. +This section describes the primary configuration data structures. +If the user wishes to see the details of a particular data structure, they are +are advised to look at the source code. After all, that is one of the +advantages of RTEMS. |