diff options
Diffstat (limited to '')
| -rw-r--r-- | Documentation/core-api/symbol-namespaces.rst (renamed from Documentation/kbuild/namespaces.rst) | 3 | ||||
| -rw-r--r-- | Documentation/kbuild/makefiles.rst | 22 | ||||
| -rw-r--r-- | Documentation/kbuild/modules.rst | 20 | ||||
| -rw-r--r-- | Documentation/kbuild/reproducible-builds.rst | 13 |
4 files changed, 21 insertions, 37 deletions
diff --git a/Documentation/kbuild/namespaces.rst b/Documentation/core-api/symbol-namespaces.rst index 982ed7b568ac..9b76337f6756 100644 --- a/Documentation/kbuild/namespaces.rst +++ b/Documentation/core-api/symbol-namespaces.rst @@ -152,3 +152,6 @@ in-tree modules:: - notice the warning of modpost telling about a missing import - run `make nsdeps` to add the import to the correct code location +You can also run nsdeps for external module builds. A typical usage is:: + + $ make -C <path_to_kernel_src> M=$PWD nsdeps diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst index 6ba9d5365ff3..b9b50553bfc5 100644 --- a/Documentation/kbuild/makefiles.rst +++ b/Documentation/kbuild/makefiles.rst @@ -954,11 +954,6 @@ When kbuild executes, the following steps are followed (roughly): From commandline LDFLAGS_MODULE shall be used (see kbuild.txt). - KBUILD_ARFLAGS Options for $(AR) when creating archives - - $(KBUILD_ARFLAGS) set by the top level Makefile to "D" (deterministic - mode) if this option is supported by $(AR). - KBUILD_LDS The linker script with full path. Assigned by the top-level Makefile. @@ -1120,23 +1115,6 @@ When kbuild executes, the following steps are followed (roughly): In this example, extra-y is used to list object files that shall be built, but shall not be linked as part of built-in.a. - header-test-y - - header-test-y specifies headers (`*.h`) in the current directory that - should be compile tested to ensure they are self-contained, - i.e. compilable as standalone units. If CONFIG_HEADER_TEST is enabled, - this builds them as part of extra-y. - - header-test-pattern-y - - This works as a weaker version of header-test-y, and accepts wildcard - patterns. The typical usage is:: - - header-test-pattern-y += *.h - - This specifies all the files that matches to `*.h` in the current - directory, but the files in 'header-test-' are excluded. - 6.7 Commands useful for building a boot image --------------------------------------------- diff --git a/Documentation/kbuild/modules.rst b/Documentation/kbuild/modules.rst index d2ae799237fd..69fa48ee93d6 100644 --- a/Documentation/kbuild/modules.rst +++ b/Documentation/kbuild/modules.rst @@ -492,18 +492,16 @@ build. to the symbols from the kernel to check if all external symbols are defined. This is done in the MODPOST step. modpost obtains the symbols by reading Module.symvers from the kernel source - tree. If a Module.symvers file is present in the directory - where the external module is being built, this file will be - read too. During the MODPOST step, a new Module.symvers file - will be written containing all exported symbols that were not - defined in the kernel. + tree. During the MODPOST step, a new Module.symvers file will be + written containing all exported symbols from that external module. ---- 6.3 Symbols From Another External Module +6.3 Symbols From Another External Module +---------------------------------------- Sometimes, an external module uses exported symbols from - another external module. kbuild needs to have full knowledge of + another external module. Kbuild needs to have full knowledge of all symbols to avoid spitting out warnings about undefined - symbols. Three solutions exist for this situation. + symbols. Two solutions exist for this situation. NOTE: The method with a top-level kbuild file is recommended but may be impractical in certain situations. @@ -521,7 +519,7 @@ build. The top-level kbuild file would then look like:: #./Kbuild (or ./Makefile): - obj-y := foo/ bar/ + obj-m := foo/ bar/ And executing:: @@ -543,8 +541,8 @@ build. all symbols defined and not part of the kernel. Use "make" variable KBUILD_EXTRA_SYMBOLS - If it is impractical to copy Module.symvers from - another module, you can assign a space separated list + If it is impractical to add a top-level kbuild file, + you can assign a space separated list of files to KBUILD_EXTRA_SYMBOLS in your build file. These files will be loaded by modpost during the initialization of its symbol tables. diff --git a/Documentation/kbuild/reproducible-builds.rst b/Documentation/kbuild/reproducible-builds.rst index ab92e98c89c8..503393854e2e 100644 --- a/Documentation/kbuild/reproducible-builds.rst +++ b/Documentation/kbuild/reproducible-builds.rst @@ -16,16 +16,21 @@ the kernel may be unreproducible, and how to avoid them. Timestamps ---------- -The kernel embeds a timestamp in two places: +The kernel embeds timestamps in three places: * The version string exposed by ``uname()`` and included in ``/proc/version`` * File timestamps in the embedded initramfs -By default the timestamp is the current time. This must be overridden -using the `KBUILD_BUILD_TIMESTAMP`_ variable. If you are building -from a git commit, you could use its commit date. +* If enabled via ``CONFIG_IKHEADERS``, file timestamps of kernel + headers embedded in the kernel or respective module, + exposed via ``/sys/kernel/kheaders.tar.xz`` + +By default the timestamp is the current time and in the case of +``kheaders`` the various files' modification times. This must +be overridden using the `KBUILD_BUILD_TIMESTAMP`_ variable. +If you are building from a git commit, you could use its commit date. The kernel does *not* use the ``__DATE__`` and ``__TIME__`` macros, and enables warnings if they are used. If you incorporate external |