Normally, the linker does not sort files and sections matched by wildcards, so
they are placed in the order in which they are seen during link. If numerous
objects with different alignments are mixed, or if objects with unusually large
alignments are present, this very likely leads to a lot of space being wasted
because of accumulated alignment gaps.
This commit forces input sections to be sorted by alignment (unless this is
overridden by the linker script), which decreases the number and the size of
alignment gaps, thus saving space.
For a typical Contiki project, this change saves nearly 1 kiB, mainly in .bss.
Note that this behavior is only enabled if the SMALL make variable is set to 1,
because this makes more sense for a size optimization.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
ELF files generated by GCC make SmartRF Flash Programmer 2 crash (only the TI
format is supported by this tool for ELFs), and binary files are not very
appropriate because they are gapless, so generate Intel HEX files since these
are very well supported by most programming tools while still flexible.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
This uses the core/dev/spi.h header and implements the spi_init()
function and the various macros for SPI operation. ssi.h contains all of
the register locations and information.
This implementation is not very versatile, mostly because I don't how to
make it flexible in the contiki system. It supports pin muxing for the
four spi pins, but other than that picks sensible defaults.
The SPI macros (like SPI_READ()) are defined in
cpu/cc2538/spi-arch.h. In order to use the SPI driver, add the following
includes to your project:
#include "spi-arch.h
#include "dev/spi.h"
Historically $(OBJECTDIR) was created when Makefile.include is read. A
consequence is that combining "clean" with "all" (or any other build
target) results in an error because the clean removes the object
directory that is required to exist when building dependencies.
Creating $(OBJECTDIR) on-demand ensures it is present when needed.
Removed creation of $(OBJECTDIR) on initial read, and added an order-only
dependency forcing its creation all Makefile* rules where the target is
explicitly or implicitly in $(OBJECTDIR).
