Zephyr builds use 'cmake' which can generate either makefiles, or use
the Ninja build tools. There are several significant advantages to
using Ninja as the build tool:
- It is significantly faster. Ninja reads a directory and stats the
files in it once. Make often stats a given directory thousands of
times, many for files that don't even exist.
- It has better output. Ninja collects commands together with their
error output. When doing multi-cpu builds, Ninja prints a status
indicator, and only prints fully verbose commands when that command
fails. Instead of having to try an piece together a given command
with its errors, they will always be together.
- Make's support of multiple CPUs is a crude hack. Make forks off
multiple processes to use multiple CPUs. These processes don't
communicate with each other (very much), which causes make to often
continue after enountering errors. It is common for a multi-CPU
make invocation to print hundreds or thousands of additional lines
after an error message.
Nearly all distros have a version of Ninja available in their package
manager, making this change of low cost.
Signed-off-by: David Brown <david.brown@linaro.org>
Most of the meat of this is in the Makefile, which is able to build the
bootloader, and two small applications, along with instructions on how
to load these into flash and test that upgrades work.
JIRA: MCUB-62
Signed-off-by: David Brown <david.brown@linaro.org>
Francesco Servidio