diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/kbuild/kbuild.rst | 11 | ||||
| -rw-r--r-- | Documentation/kbuild/llvm.rst | 31 | ||||
| -rw-r--r-- | Documentation/kbuild/makefiles.rst | 2 |
3 files changed, 38 insertions, 6 deletions
diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst index 2d1fc03d346e..ef19b9c13523 100644 --- a/Documentation/kbuild/kbuild.rst +++ b/Documentation/kbuild/kbuild.rst @@ -77,6 +77,17 @@ HOSTLDLIBS ---------- Additional libraries to link against when building host programs. +.. _userkbuildflags: + +USERCFLAGS +---------- +Additional options used for $(CC) when compiling userprogs. + +USERLDFLAGS +----------- +Additional options used for $(LD) when linking userprogs. userprogs are linked +with CC, so $(USERLDFLAGS) should include "-Wl," prefix as applicable. + KBUILD_KCONFIG -------------- Set the top-level Kconfig file to the value of this environment diff --git a/Documentation/kbuild/llvm.rst b/Documentation/kbuild/llvm.rst index d32616891dcf..b854bb413164 100644 --- a/Documentation/kbuild/llvm.rst +++ b/Documentation/kbuild/llvm.rst @@ -49,17 +49,36 @@ example: :: LLVM Utilities -------------- -LLVM has substitutes for GNU binutils utilities. Kbuild supports ``LLVM=1`` -to enable them. :: - - make LLVM=1 - -They can be enabled individually. The full list of the parameters: :: +LLVM has substitutes for GNU binutils utilities. They can be enabled individually. +The full list of supported make variables:: make CC=clang LD=ld.lld AR=llvm-ar NM=llvm-nm STRIP=llvm-strip \ OBJCOPY=llvm-objcopy OBJDUMP=llvm-objdump READELF=llvm-readelf \ HOSTCC=clang HOSTCXX=clang++ HOSTAR=llvm-ar HOSTLD=ld.lld +To simplify the above command, Kbuild supports the ``LLVM`` variable:: + + make LLVM=1 + +If your LLVM tools are not available in your PATH, you can supply their +location using the LLVM variable with a trailing slash:: + + make LLVM=/path/to/llvm/ + +which will use ``/path/to/llvm/clang``, ``/path/to/llvm/ld.lld``, etc. + +If your LLVM tools have a version suffix and you want to test with that +explicit version rather than the unsuffixed executables like ``LLVM=1``, you +can pass the suffix using the ``LLVM`` variable:: + + make LLVM=-14 + +which will use ``clang-14``, ``ld.lld-14``, etc. + +``LLVM=0`` is not the same as omitting ``LLVM`` altogether, it will behave like +``LLVM=1``. If you only wish to use certain LLVM utilities, use their respective +make variables. + The integrated assembler is enabled by default. You can pass ``LLVM_IAS=0`` to disable it. diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst index b008b90b92c9..11a296e52d68 100644 --- a/Documentation/kbuild/makefiles.rst +++ b/Documentation/kbuild/makefiles.rst @@ -982,6 +982,8 @@ The syntax is quite similar. The difference is to use "userprogs" instead of When linking bpfilter_umh, it will be passed the extra option -static. + From command line, :ref:`USERCFLAGS and USERLDFLAGS <userkbuildflags>` will also be used. + 5.4 When userspace programs are actually built ---------------------------------------------- |