- Add `byteorder_bebuftohll()` to read an 64 bit value from a big endian buffer
- Add `byteorder_htobebufll()` to write an 64 bit value into a big endian buffer
Replace accesses to `sched_active_thread`, `sched_active_pid`, and
`sched_threads` with `thread_get_active()`, `thread_get_active_pid()`, and
`thread_get_unchecked()` where sensible.
- Add `thread_get_active()` to access the TCB
- Add `thread_get_unchecked()` as fast alternative to `thread_get()`
- Drop `volatile` qualifier in `thread_get()`
- Right now every caller of this function does this. It is better to
contain this undefined behavior to at least one place in code
The `clz` instruction pretty much implements getting the most significant bit
in hardware, so use it instead of the software implementation.
This reults in both a reduction in code size as in a speedup:
master:
text data bss dec hex filename
14816 136 2424 17376 43e0 tests/bitarithm_timings/bin/same54-xpro/tests_bitarithm_timings.elf
+ bitarithm_msb: 3529411 iterations per second
this patch:
text data bss dec hex filename
14768 136 2424 17328 43b0 tests/bitarithm_timings/bin/same54-xpro/tests_bitarithm_timings.elf
+ bitarithm_msb: 9230761 iterations per second
Big endian buffers on big endian systems are already in big endian byte order,
so no byte shuffling is needed. However, byte buffers might be unaligned, so
copy operations that are safe with unaligned memory accesses need to be
used.
It can be desirable to not have the boot message printed each time
(e.g. logs are transferred over a wireless link on battery) while
still retaining the ability to receive INFO level logs.
This adds the option to disable the boot-up message (and also to customize
it if that is desireable).
Those macros are all about convenience. However, always using 64 bit makes casts
nececcary that goes against the idea of having a convenience macro.
E.g. when printing a frequency in KHZ one might want to do
printf("freq: %lu kHz\n", freq / KHZ(1));
leads to an error
> error: format '%lu' expects argument of type 'long unsigned int', but argument 2 has type 'long long unsigned int'
Now we would have to cast - `%llu` is not available with newlib-nano and wholly
uneccecary.
Only use 64 bit artithmetic where necessary (GHZ, GiB), not for smaller units.
Receiving threads must not modify the contents of the message as this
is racy by definition.
Also make `msg_bus_post()` accept `const void*` instead of `char *`.
irq_% are not inlined by the compiler which leads to it branching
to a function that actually implement a single machine instruction.
Inlining these functions makes the call more efficient as well as
saving some bytes in ROM.
This commit removes the #error from the thread_flags header.
This #error makes the usage of
if(IS_USED(MODULE_THAT_DEPENDS_ON_THREAD_FLAGS)) pattern harder,
because the error is triggered each time the header is included.
If a module uses any thread_flags function it will fail in link time
anyway.
bitarithm.h is not needed for the interface of shed but may cause conflicts
due to different definitions of SETBIT and CLRBIT
common implementations are: (value, offset) xor (value, mask) bitarithm
implements the later
frac.c and nrf52/usbdev.c use bitarithm.h but where missing the include
sam0/rtt.c defined a bit using mask from bitarithm,
changed that to the soulution used in sam0/rtc.c
The DEBUG() function requires a minimal stack size for printf().
This is not always availiable.
To still allow static debug messages, introduce DEBUG_PUTS() that
gets resolved to puts() and does not carry such stack size requirements.
IS_ACTIVE allows to evaluate macro definitions in non-preprocessor
expressions. It takes a macro that may be defined to 1 or not defined at
all and expands to 1 or 0 respectively.
