Document number
205065
Version
Rev. N
Issue date
2019-02-04
Sirius OBC and TCM User Manual
Page
63
of
174
5.6.4.5. Runtime-determined size usage mode
This usage mode allows support for differing page sizes at runtime, and defines
MASSMEM_PAGE_BYTES_MAX and MASSMEM_SPARE_AREA_BYTES_MAX for use at
compile time, when the sizes are not yet known. At runtime, the available page and spare
area sizes will be accessible via the MASSMEM_IO_GET_PAGE_BYTES and
MASSMEM_IO_GET_SPARE_AREA_BYTES
ioctl()
commands.
This usage mode is available both with and without the
BSP_AAC_MASSMEM_ENABLE_32GB define set:
•
If the driver is compiled
without
the BSP_AAC_MASSMEM_ENABLE_32GB
define set, the mass memory (and corresponding available page and spare area
size) will always be exposed as 16GB regardless of the chip type at runtime.
This can be useful for migrating applications to the runtime-determined size usage
mode without removing support for the same-size usage mode.
•
If the driver is compiled
with
the BSP_AAC_MASSMEM_ENABLE_32GB define
set, the mass memory (and corresponding available page and spare area size) will
vary between exposing 16GB and 32GB depending on the chip type at runtime.
Please note that this disables support for the same-size usage mode.
BSP_AAC_MASSMEM_ENABLE_32GB can be set as an environment or Makefile variable
when compiling the RTEMS BSP.
