kbuild: introduce hostprogs-always-y and userprogs-always-y

[linux-2.6-microblaze.git] / Documentation / kbuild / makefiles.rst

diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index 14d8e7d..b81b891 100644 (file)
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -749,6 +749,10 @@ Both possibilities are described in the following.
                hostprogs     := lxdialog
                always-y      := $(hostprogs)
 
+       Kbuild provides the following shorthand for this:
+
+               hostprogs-always-y := lxdialog
+
        This will tell kbuild to build lxdialog even if not referenced in
        any rule.
 
@@ -831,7 +835,32 @@ The syntax is quite similar. The difference is to use "userprogs" instead of
 5.4 When userspace programs are actually built
 ----------------------------------------------
 
-       Same as "When host programs are actually built".
+       Kbuild builds userspace programs only when told to do so.
+       There are two ways to do this.
+
+       (1) Add it as the prerequisite of another file
+
+       Example::
+
+               #net/bpfilter/Makefile
+               userprogs := bpfilter_umh
+               $(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh
+
+       $(obj)/bpfilter_umh is built before $(obj)/bpfilter_umh_blob.o
+
+       (2) Use always-y
+
+       Example::
+
+               userprogs := binderfs_example
+               always-y := $(userprogs)
+
+       Kbuild provides the following shorthand for this:
+
+               userprogs-always-y := binderfs_example
+
+       This will tell Kbuild to build binderfs_example when it visits this
+       Makefile.
 
 6 Kbuild clean infrastructure
 =============================