Add 'turbo' logging feature. When enabled, short logs (no argument
or one numeric, 32 bit argument) are handled in a special way that
is much faster than the default one (5-10x faster). Additionally,
there is an option to remove all other logs from the system which
allows to not include almost any logging framework code in the
binary (~170 bytes of code is needed). It may be especially
valueable for memory constraint targets (ppr, flpr) where with
only 170 byte of code (+code for each log message) we can provide
limited formatted string logging support.
'Turbo' logging is using following to achieve that:
- logging strings are put into a memory section and additional
memory section is created which holds addresses of those strings.
Index in that array is used to identify a string (32 bit address
is encoded into a smaller number, 15 bits is more than enough).
This index is used for a STMESP register set (there are 2^16
available). So STMESP channel encodes string.
- Logging level is stringified and prepended to a string
- Source ID is encoded by using DM16 (so far not used).
- Log without arguments is written as DMTS16
- Log with one argumetn is written as DM16+DMTS32
Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>
752f8b0176