-
Notifications
You must be signed in to change notification settings - Fork 2k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge pull request #4495 from authmillenon/doc/enh/2015.12/creating-a…
…pplication doc: add page about creating an application (2015.12 version)
- Loading branch information
Showing
3 changed files
with
96 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,93 @@ | ||
Creating an application {#creating-an-application} | ||
======================= | ||
|
||
[TOC] | ||
|
||
To create your own application you need to create a directory containing one or | ||
multiple C file(s) with your source code and a Makefile. A template Makefile is | ||
available in the `dist` folder of the | ||
[RIOT repository](https://github.com/RIOT-OS/RIOT). | ||
|
||
The main function {#the-main-function} | ||
================= | ||
After the board is initialized, RIOT starts two threads: the idle thread and | ||
the main thread. The idle thread has the lowest priority and will run whenever | ||
no other thread is ready to run. It will automatically use the lowest possible | ||
power mode for the device. The main thread - configured with a default priority | ||
that is right in the middle between the lowest and the highest available | ||
priorities - is the first thread that runs and calls the `main()` function. | ||
This function needs to be defined in the source code of the application | ||
(typically located in `main.c`). | ||
|
||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ {.c} | ||
#include <stdio.h> | ||
int main(void) | ||
{ | ||
puts("Hello World!"); | ||
return 0; | ||
} | ||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | ||
|
||
The application's Makefile {#the-applications-makefile} | ||
========================== | ||
The minimal Makefile {#the-minimal-makefile} | ||
-------------------- | ||
At minimum the Makefile of an application (see @ref getting-started) needs to | ||
define the following macros: | ||
* `APPLICATION`: should contain the name of your application | ||
* `RIOTBASE`: specifies the path to your copy of the RIOT repository (note | ||
that you may want to use `$(CURDIR)` here, to give a relative path) | ||
|
||
The `BOARD` macro is also required and recommended to be set to `native` by | ||
default, but is recommended to be overridable with the `?=` operator. | ||
Additionally, it is required to include the `Makefile.include` from the | ||
`RIOTBASE`. | ||
|
||
~~~~~~~~~~~~~~~~~~~~~~~~~~~ {.mk} | ||
# Set the name of your application: | ||
APPLICATION = foobar | ||
# If no BOARD is found in the environment, use this default: | ||
BOARD ?= native | ||
# This has to be the absolute path to the RIOT base directory: | ||
RIOTBASE ?= $(CURDIR)/../../RIOT | ||
include $(RIOTBASE)/Makefile.include | ||
~~~~~~~~~~~~~~~~~~~~~~~~~~~ | ||
|
||
How to handle unsupported boards? {#handle-unsupported-boards} | ||
--------------------------------- | ||
Sometimes it is necessary to exclude boards because they don't provide a | ||
required functionality or don't have sufficient memory. RIOT's build system | ||
looks for the macros `BOARD_BLACKLIST`, `BOARD_WHITELIST`, and | ||
`BOARD_INSUFFICIENT_MEMORY`. Any board name that is not included in | ||
`BOARD_WHITELIST` will issue a message that one has to expect errors if they | ||
build the application for the board referred by that name. The list can also be | ||
used by a CI system to not build the application for this board at all. A board | ||
that is included in `BOARD_BLACKLIST` will show the same behavior. The build | ||
system evaluates `BOARD_WHITELIST` first and then `BOARD_BLACKLIST`. The | ||
`BOARD_INSUFFICIENT_MEMORY` macro is similar to `BOARD_BLACKLIST` but will | ||
build in any case. A CI system can use the information provided by the | ||
`BOARD_INSUFFICIENT_MEMORY` macro to skip the linking step in the build | ||
process, since some linkers will issue an error if the code won't fit the | ||
target board's flash memory or RAM. | ||
|
||
Including modules {#including-modules} | ||
----------------- | ||
By default a RIOT application comprises only of the applications' code itself, | ||
the kernel, and platform specific code. In order to use additional modules, | ||
such as a particular @ref drivers "device driver" or @ref sys "a system | ||
library" (including @ref net "networking capabilities"), you have to append the | ||
modules' names to the USEMODULE variable. For example, to build an application | ||
using the SHT11 temperature sensor and UDP/IPv6 functionalities of the GNRC | ||
network stack, your Makefile needs to contain these lines: | ||
|
||
~~~~~~~~~~~~~~~~~~~~~~~~~~~ {.mk} | ||
USEMODULE += sht11 | ||
USEMODULE += gnrc_ipv6_default | ||
USEMODULE += gnrc_udp | ||
~~~~~~~~~~~~~~~~~~~~~~~~~~~ | ||
|
||
Modules typically pull in all required dependencies. |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters