RTEMS C User's Guide
The RTEMS RAM 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 RAM Workspace.
The starting address of the RTEMS RAM Workspace must
be aligned on a four-byte boundary. Failure to properly align
the workspace area will result in the
rtems_fatal_error_occurred
directive being invoked with the
RTEMS_INVALID_ADDRESS error code.
A worksheet is provided in the Memory Requirements chapter of the Applications Supplement document for a specific target processor to assist the user in calculating the minimum size of the RTEMS RAM Workspace for each application. The value calculated with this worksheet is the minimum value that should be specified as the work_space_size parameter of the Configuration Table. The user is cautioned that future versions of RTEMS may not have the same memory requirements per object. Although the value calculated is sufficient for a particular target processor and release of RTEMS, memory usage is subject to change across versions and target processors. The user is advised to allocate somewhat more memory than the worksheet recommends to insure compatibility with future releases for a specific target processor and other target processors. To avoid problems, the user should recalculate the memory requirements each time one of the following events occurs:
Failure to provide enough space in the RTEMS RAM
Workspace will result in the
rtems_fatal_error_occurred directive
being invoked with the appropriate error code.
RTEMS C User's Guide
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