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author | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2011-11-13 09:54:45 +0100 |
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committer | Peter Korsgaard <jacmet@sunsite.dk> | 2011-11-13 21:28:50 +0100 |
commit | d0afbdad6b5a5b0fe7b0665cc0d9a337f0ace412 (patch) | |
tree | ca679d3355025f637093e310b4eb5f821c51ec23 | |
parent | d031a031bdfbccec41a5d7c4c566765b4bb4b6a5 (diff) | |
download | buildroot-novena-d0afbdad6b5a5b0fe7b0665cc0d9a337f0ace412.tar.gz buildroot-novena-d0afbdad6b5a5b0fe7b0665cc0d9a337f0ace412.zip |
doc: more details about expressing dependencies in Config.in
[Peter: Minor tweak]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
-rw-r--r-- | docs/manual/adding-packages-directory.txt | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/docs/manual/adding-packages-directory.txt b/docs/manual/adding-packages-directory.txt index 2e8786a20..58f026261 100644 --- a/docs/manual/adding-packages-directory.txt +++ b/docs/manual/adding-packages-directory.txt @@ -46,6 +46,51 @@ supposed to contain anything but the 'bare' name of the package. source "package/libfoo/Config.in" -------------------------- +The +Config.in+ file of your package must also ensure that +dependencies are enabled. Typically, Buildroot uses the following +rules: + +* Use a +select+ type of dependency for dependencies on + libraries. These dependencies are generally not obvious and it + therefore make sense to have the kconfig system ensure that the + dependencies are selected. For example, the _libgtk2_ package uses + +select BR2_PACKAGE_LIBGLIB2+ to make sure this library is also + enabled. + +* Use a +depends on+ type of dependency when the user really needs to + be aware of the dependency. Typically, Buildroot uses this type of + dependency for dependencies on toolchain options (large file + support, RPC support, IPV6 support), or for dependencies on "big" + things, such as the X.org system. In some cases, especially + dependency on toolchain options, it is recommended to add a + +comment+ displayed when the option is not enabled, so that the user + knows why the package is not available. + +An example illustrates both the usage of +select+ and +depends on+. + +-------------------------- +config BR2_PACKAGE_ACL + bool "acl" + select BR2_PACKAGE_ATTR + depends on BR2_LARGEFILE + help + POSIX Access Control Lists, which are used to define more + fine-grained discretionary access rights for files and + directories. + This package also provides libacl. + + http://savannah.nongnu.org/projects/acl + +comment "acl requires a toolchain with LARGEFILE support" + depends on !BR2_LARGEFILE +-------------------------- + + +Note that such dependencies will make sure that the dependency option +is also enabled, but not necessarily built before your package. To do +so, the dependency also needs to be expressed in the +.mk+ file of the +package. + The +.mk+ file ~~~~~~~~~~~~~~ |