docs/manual: document $(FOO_PKGDIR)

In the manual, add a note that packages can use $(FOO_PKGDIR) to get the
path to the directory containg the .mk and Config.in files, if they need
it to e.g. copy files from there, like startup scripts, systemd units or
any other resource.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Samuel Martin <s.martin49@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

diff --git a/docs/manual/adding-packages-generic.txt b/docs/manual/adding-packages-generic.txt
index a7143e428441512dd2c0262312752cddc3409abd..02a43d6b1d5228ea3d67b6ce03861f5eea2f821f 100644 (file)
--- a/docs/manual/adding-packages-generic.txt
+++ b/docs/manual/adding-packages-generic.txt
@@ -495,6 +495,11 @@ endef
 
 In the action definitions, you can use the following variables:
 
+* +$(FOO_PKGDIR)+ contains the path to the directory containing the
+  +foo.mk+ and +Config.in+ files. This variable is useful when it is
+  necessary to install a file bundled in Buildroot, like a runtime
+  configuration file, a splashscren image...
+
 * +$(@D)+, which contains the directory in which the package source
   code has been uncompressed.