* Use compile-time detection of hardware CRC capability, so unneeded
code and tables do not go into the image.
* Add global JSON config option to allow choice between no tables,
16-entry tables or 256-entry tables for software CRC. Default set
to 16-entry, reducing ROM size from previous 256-entry.
* Allow manual override in template parameter to force software or
bitwise CRC for a particular instance.
* Micro-optimisations, particularly use of `RBIT` instruction and
optimising bitwise computation using inline assembler.
Incompatible changes:
* Remove special-case "POLY_32BIT_REV_ANSI" - users can use standard
POLY_32BIT_ANSI, which now uses the same 16-entry tables by default,
or can use hardware acceleration, which was disabled for
POLY_32BIT_REV_ANSI. MbedCRC<POLY_32BIT_ANSI, 32, CrcMode::TABLE> can
be used to force software like POLY_32BIT_REV_ANSI.
* The precomputed table for POLY_16BIT_IBM had errors - this has been
corrected, but software CRC results will be different from the previous
software calculation.
* < 8-bit CRC results are no longer are shifted up in the output value,
but placed in the lowest bits, like other sizes. This means that code
performing the SD command CRC will now need to use `(crc << 1) | 1`,
rather than `crc | 1`.
When a Doxygen group has been defined (created), all its needed to add
documentation to that group is `\addtogroup`. Since all the information
about the group is preserved, it is not necessary to mention the group
hierarchy again with `\ingroup`. This PR removes unnecessary Doxygen lines
across the `drivers`, `events`, `platform` and `rtos` directories.
It also ensures that new groups are created with `\defgroup` once and
referenced with `\addtogroup` whenever documentation needs to be added to
an existing group.
* Change Doxygen groups structure, splitting first by Public/Internal
This commit also does the following:
* groups the documentation of related API
* moves `events/internal/equeue.h` to `events/equeue.h`
* merges `events/source/README.md` to `events/README.md`
Separate drivers, events, and rtos internal APIs from public APIs.
* Move source files to source subdirs
* Move internal headers to internal subdirs
* Add Doxygen comments for documenting internal and public APIs
* Remove source code from header files in order to remove include pre-processor directives
that included header files not directly used by said header files
* Explicitly include header files instead of implicit inclusions via third-party header files.
Release Notes
This will break user code that was using an internal API as the internal header files have been moved.
This will only break if the user was including the header file using a namespace (i.e #include "foo/bar.h" instead of #include "bar.h"
The DEVICE_FOO macros are always defined (either 0 or 1).
This patch replaces any instances of a define check on a DEVICE_FOO
macro with value test instead.
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
When length is zero, the buffer is not accessed. The CRC functions are used
inside several other layers where a 0-length buffer may have meanings in
different contexts and being able to pass 0-length NULL buffers to CRC as a
noop simplifies the code.
CRC used in LittleFS is Reversed ANSI, hence new polynomial added.
Reversed polynomials perform shift in reverse direction of standard
polynomial, and we do not have option to notify reverse shift to hardware.
Hence this option is available in software only.
Template specialization didn't work after addition of default constructor
for unsupported polynomials. Since the argument type and count are same,
compiler always selects the default constructor.
- Move CRC polynomial enum into HAL layer, so it's accessible from platform
implementations
- Add enum to CRC class to indicate which mode the CRC class should use:
HARDWARE, TABLE, or BITWISE
- Add calls to HAL Hardware CRC API to each of the compute functions when the
class is in HARDWARE mode.
- Add missing constructor call to template constructor, and remove const from
delegating constructor.
CRC class `MbedCRC.h` is templated class created to support hardware/software
CRCs. Default CRC will be hardware CRC when support for HAL is available.
Polynomial tables are available for 8/16 bit CCITT, 7/16 bit for SD card and
32-bit ANSI. Polynomial table implementation will be used if Hardware CRC is
not available.
In case device does not have hardware CRC and polynomial table is not supported,
CRC is still available and is computed runtime bit by bit for all data input.
Kevin Bracey
Hugues Kamba
Amanda Butler
Bartek Szatkowski
George Psimenos
kegilbert
Alastair D'Silva
Martin Kojtal
Deepika
Mel W
Cruz Monrreal II
Maciej Bocianski
Christopher Haster
Steven Cartmell