osd-contiki/doc/build-system.txt

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/**
\defgroup buildsystem The Contiki build system
The Contiki build system is designed to make it easy to compile
Contiki applications for either to a hardware platform or into a
simulation platform by simply supplying different parameters to the
<tt>make</tt> command, without having to edit makefiles or modify
the application code.
The file example project in examples/hello-world/ shows how the
Contiki build system works. The <tt>hello-world.c</tt> application
can be built into a complete Contiki system by running <tt>make</tt>
in the examples/hello-world/ directory. Running <tt>make</tt> without
parameters will build a Contiki system using the <tt>native</tt>
target. The <tt>native</tt> target is a special Contiki platform that
builds an entire Contiki system as a program that runs on the
development system. After compiling the application for the
<tt>native</tt> target it is possible to run the Contiki system with
the application by running the file <tt>hello-world.native</tt>.
To compile the hello-world application into a stand-alone executable
that can be loaded into a running Contiki system, the command
<tt>make hello-world.ce</tt> is used. To build an executable file for
the Sky platform, <tt>make TARGET=sky hello-world.sky</tt> is run.
To avoid having to type <tt>TARGET=</tt> every time <tt>make</tt> is
run, it is possible to run <tt>make TARGET=sky savetarget</tt> to
save the selected target as the default target platform for
subsequent invocations of <tt>make</tt>. A file called
<tt>Makefile.target</tt> containing the currently saved target is
saved in the project's directory.
\section buildsystem-makefiles Makefiles used in the Contiki build system
The Contiki build system is composed of a number of Makefiles. These
are:
- <tt>Makefile</tt>: the project's makefile, located in the project directory.
- <tt>Makefile.include</tt>: the system-wide Contiki makefile,
located in the root of the Contiki source tree.
- <tt>Makefile.\$(TARGET)</tt> (where \$(TARGET) is the name of the
platform that is currently being built): rules for the specific
platform, located in the platform's subdirectory in the platform/ directory.
- <tt>Makefile.\$(CPU)</tt> (where \$(CPU) is the name of the CPU or
microcontroller architecture used on the platform for which Contiki
is built): rules for the CPU architecture, located in the CPU
architecture's subdirectory in the cpu/ directory.
- <tt>Makefile.\$(APP)</tt> (where \$(APP) is the name of an
application in the apps/ directory): rules for applications in the
apps/ directories. Each application has its own makefile.
The Makefile in the project's directory is intentionally simple. It
specifies where the Contiki source code resides in the system and
includes the system-wide Makefile, <tt>Makefile.include</tt>. The
project's makefile can also define in the <tt>APPS</tt> variable a
list of applications from the apps/ directory that should be included
in the Contiki system. The Makefile used in the hello-world example
project looks like this:
\code
CONTIKI = ../..
all: hello-world
include $(CONTIKI)/Makefile.include
\endcode
First, the location of the Contiki source code tree is given by
defining the <tt>CONTIKI</tt> variable. Next, the name of the
application is defined. Finally, the system-wide
<tt>Makefile.include</tt> is included.
The <tt>Makefile.include</tt> contains definitions of the C files of
the core Contiki system. <tt>Makefile.include</tt> always reside in
the root of the Contiki source tree. When <tt>make</tt> is run,
<tt>Makefile.include</tt> includes the <tt>Makefile.\$(TARGET)</tt>
as well as all makefiles for the applications in the <tt>APPS</tt>
list (which is specified by the project's <tt>Makefile</tt>).
<tt>Makefile.\$(TARGET)</tt>, which is located in the
platform/\$(TARGET)/ directory, contains the list of C files that the
platform adds to the Contiki system. This list is defined by the
<tt>CONTIKI_TARGET_SOURCEFILES</tt> variable. The
<tt>Makefile.\$(TARGET)</tt> also includes the
<tt>Makefile.\$(CPU)</tt> from the cpu/\$(CPU)/ directory.
The <tt>Makefile.\$(CPU)</tt> typically contains definitions for the
C compiler used for the particular CPU. If multiple C compilers are
used, the <tt>Makefile.\$(CPU)</tt> can either contain a conditional
expression that allows different C compilers to be defined, or it can
be completely overridden by the platform specific makefile
<tt>Makefile.\$(TARGET)</tt>.
@{
*/
/**
@}
*/