When using MbedCRC, init value must be non-reversed, regardless of
`reflect_data` or `reflect_out` settings. This means we need to reflect
the intermediate output before passing using it as the next init value.
(In GCC this ends up putting in two `RBIT` instructions back-to-back,
because it's implemented as assembler, so it doesn't know how to
optimise. In ARMC6, `__RBIT` is implemented as an intrinsic, so adding
this reflection cancels the existing reflection and makes the code
smaller).
* Make mbed_error use bitwise MbedCRC call rather than local
implementation.
* Remove use of POLY_32BIT_REV_ANSI from LittleFS.
* Move some MbedCRC instances closer to use - construction cost is
trivial, and visibility aids compiler optimisation.
* Make mbed_error use bitwise MbedCRC call rather than local
implementation.
* Remove use of POLY_32BIT_REV_ANSI from LittleFS.
* Move some MbedCRC instances closer to use - construction cost is
trivial, and visibility aids compiler optimisation.
* Refactor some headers to use relative path from Mbed OS root.
* Refactor some data types to compile on 64bit machines.
* Refactor some debug traces to use mbed_trace.
IAR compilation fails at `_fs = { 0 };` due to
```
[Error] FATFileSystem.cpp@285,0: [Pe029]: expected an expression
```
Changing that object initializer list instead, as that seems
to pass IAR compilation, too.
Changed original memset to object initialiser list based on review
feedback from Kevin Bracey.
Macro which restricted compilation to GCC_ARM is removed.
Existing read_write() test is amended to call stat() and check that correct size is returned.
The most common issue with using littlefs in mbed-os is when users
change from littlefs->FAT->littlefs (or with MBR or similar). When this
corrupts the superblock, littlefs tries to fall back to the backup
superblock. However, at this point in the time the old superblock may be
very out-of-date and pointing to an incorrect filesystem.
There's no complete solution to a malicious modification of the
filesystem (short of checking all metadata+data, a very expensive
operation), but we can at least expand our validation to all of the
metadata for the filesystem. This at least catches the common issues
with changing between different filesystems.
Adding new modules inside the namespace could be breaking change for existing code base
hence add `using namespace::class` for classes newly added to mbed namespace to maintian
backwards compatibility.
MBED_NO_GLOBAL_USING_DIRECTIVE is added to remove auto-addition of namespace
Macro guard `MBED_NO_GLOBAL_USING_DIRECTIVE` is added around namespace, to avoid
polluting users namespace.
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.