riot-ci/RIOT
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Merge pull request #14154 from akshaim/Kconfig_doc

Browse Source 
doc/kconfig.md : Update documentation
This commit is contained in:
Leandro Lanzieri 2020-06-03 16:48:54 +02:00 committed by GitHub
commit d6bdd69514
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 17 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
doc/doxygen/src/kconfig/kconfig.md
View File

@ -375,6 +375,23 @@ menuconfig, the file will not be re-built anymore, and any changes by manually
editing the source files will have no effect. To go back to manual edition editing the source files will have no effect. To go back to manual edition
a `make clean` has to be issued in the application directory. a `make clean` has to be issued in the application directory.
## Appendix D: A few key aspects while exposing a macro to Kconfig {#kconfig-appendix-d}
A macro that holds a 0 or 1 is modelled in Kconfig as a `bool` symbol. References to this macro
can then make use of IS_ACTIVE macro from kernel_defines.h with C conditionals
for conditional compilation.
[FXOS8700 driver exposure to Kconfig](https://github.com/RIOT-OS/RIOT/pull/13914)
can be considered as an example. If the macro is defined as `TRUE` by default,
a new symbol gets introduced to invert the semantics. The recommended
practice is to add a new symbol and expose it to Kconfig while the old one is
tagged to be deprecated. The process is documented in this
[commit](https://github.com/RIOT-OS/RIOT/pull/13129/commits/c7b6dc587cf20f3177abe0417a408b6ab90d0ff8)
There may be cases where a macro is expected to hold only specific values, e.g.
'GNRC_IPV6_MSG_QUEUE_SIZE' expressed as the power of two. These may be modelled
in such a way that a new macro is introduced to hold the restricted figures
while operators are added to arrive at the desired value. The process is
documented in this [pull request.](https://github.com/RIOT-OS/RIOT/pull/14086)
# Useful references {#kconfig-useful-references} # Useful references {#kconfig-useful-references}
- [Kconfig language specification](https://www.kernel.org/doc/html/latest/kbuild/kconfig-language.html) - [Kconfig language specification](https://www.kernel.org/doc/html/latest/kbuild/kconfig-language.html)
- [Kconfig macro language specification](https://www.kernel.org/doc/html/latest/kbuild/kconfig-macro-language.html) - [Kconfig macro language specification](https://www.kernel.org/doc/html/latest/kbuild/kconfig-macro-language.html)