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This makes it easier to automatically generate parts of the manager documentation in the future. Update #3993.
56 lines
2.2 KiB
ReStructuredText
56 lines
2.2 KiB
ReStructuredText
.. SPDX-License-Identifier: CC-BY-SA-4.0
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.. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR)
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Operations
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==========
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Creating a Partition
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--------------------
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The ``rtems_partition_create`` directive creates a partition with a
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user-specified name. The partition's name, starting address, length and buffer
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size are all specified to the ``rtems_partition_create`` directive. RTEMS
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allocates a Partition Control Block (PTCB) from the PTCB free list. This data
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structure is used by RTEMS to manage the newly created partition. The number
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of buffers in the partition is calculated based upon the specified partition
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length and buffer size. If successful,the unique partition ID is returned to
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the calling task.
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Obtaining Partition IDs
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-----------------------
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When a partition is created, RTEMS generates a unique partition ID and assigned
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it to the created partition until it is deleted. The partition ID may be
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obtained by either of two methods. First, as the result of an invocation of
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the ``rtems_partition_create`` directive, the partition ID is stored in a user
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provided location. Second, the partition ID may be obtained later using the
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``rtems_partition_ident`` directive. The partition ID is used by other
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partition manager directives to access this partition.
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Acquiring a Buffer
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------------------
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A buffer can be obtained by calling the ``rtems_partition_get_buffer``
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directive. If a buffer is available, then it is returned immediately with a
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successful return code. Otherwise, an unsuccessful return code is returned
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immediately to the caller. Tasks cannot block to wait for a buffer to become
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available.
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Releasing a Buffer
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------------------
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Buffers are returned to a partition's free buffer chain with the
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``rtems_partition_return_buffer`` directive. This directive returns an error
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status code if the returned buffer was not previously allocated from this
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partition.
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Deleting a Partition
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--------------------
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The ``rtems_partition_delete`` directive allows a partition to be removed and
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returned to RTEMS. When a partition is deleted, the PTCB for that partition is
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returned to the PTCB free list. A partition with buffers still allocated
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cannot be deleted. Any task attempting to do so will be returned an error
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status code.
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