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Diffstat (limited to 'Documentation/kbuild/makefiles.rst')
| -rw-r--r-- | Documentation/kbuild/makefiles.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst index 7964e0c245ae..d36519f194dc 100644 --- a/Documentation/kbuild/makefiles.rst +++ b/Documentation/kbuild/makefiles.rst @@ -449,6 +449,20 @@ $(obj) to prerequisites are referenced with $(src) (because they are not generated files). +$(srcroot) + $(srcroot) refers to the root of the source you are building, which can be + either the kernel source or the external modules source, depending on whether + KBUILD_EXTMOD is set. This can be either a relative or an absolute path, but + if KBUILD_ABS_SRCTREE=1 is set, it is always an absolute path. + +$(srctree) + $(srctree) refers to the root of the kernel source tree. When building the + kernel, this is the same as $(srcroot). + +$(objtree) + $(objtree) refers to the root of the kernel object tree. It is ``.`` when + building the kernel, but it is different when building external modules. + $(kecho) echoing information to user in a rule is often a good practice but when execution ``make -s`` one does not expect to see any output |