forked from luck/tmp_suning_uos_patched
Documentation/kbuild: modules.txt cleanup
A few modifications done for consistency, such as adding the shell prompt for command line examples and trailing slash for directories. Also corrects the module include header and fixes a few grammar issues that I introduced. Signed-off-by: matt mooney <mfm@muteddisk.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
This commit is contained in:
matt mooney
Michal Marek
parent
9f02186c23
commit
5793210cb1
|
|
@ -1,11 +1,11 @@
|
|||
Building External Modules
|
||||
|
||||
This document describes how-to build an out-of-tree kernel module.
|
||||
This document describes how to build an out-of-tree kernel module.
|
||||
|
||||
=== Table of Contents
|
||||
|
||||
=== 1 Introduction
|
||||
=== 2 How-to Build External Modules
|
||||
=== 2 How to Build External Modules
|
||||
--- 2.1 Command Syntax
|
||||
--- 2.2 Options
|
||||
--- 2.3 Targets
|
||||
|
|
@ -48,9 +48,9 @@ easily accomplished, and a complete example will be presented in
|
|||
section 3.
|
||||
|
||||
|
||||
=== 2. How-to Build External Modules
|
||||
=== 2. How to Build External Modules
|
||||
|
||||
To build external modules, you must have a pre-built kernel available
|
||||
To build external modules, you must have a prebuilt kernel available
|
||||
that contains the configuration and header files used in the build.
|
||||
Also, the kernel must have been built with modules enabled. If you are
|
||||
using a distribution kernel, there will be a package for the kernel you
|
||||
|
|
@ -69,19 +69,19 @@ executed to make module versioning work.
|
|||
|
||||
The command to build an external module is:
|
||||
|
||||
make -C <path_to_kernel_src> M=$PWD
|
||||
$ make -C <path_to_kernel_src> M=$PWD
|
||||
|
||||
The kbuild system knows that an external module is being built
|
||||
due to the "M=<dir>" option given in the command.
|
||||
|
||||
To build against the running kernel use:
|
||||
|
||||
make -C /lib/modules/`uname -r`/build M=$PWD
|
||||
$ make -C /lib/modules/`uname -r`/build M=$PWD
|
||||
|
||||
Then to install the module(s) just built, add the target
|
||||
"modules_install" to the command:
|
||||
|
||||
make -C /lib/modules/`uname -r`/build M=$PWD modules_install
|
||||
$ make -C /lib/modules/`uname -r`/build M=$PWD modules_install
|
||||
|
||||
--- 2.2 Options
|
||||
|
||||
|
|
@ -121,7 +121,7 @@ executed to make module versioning work.
|
|||
|
||||
modules_install
|
||||
Install the external module(s). The default location is
|
||||
/lib/modules/<kernel_release>/extra, but a prefix may
|
||||
/lib/modules/<kernel_release>/extra/, but a prefix may
|
||||
be added with INSTALL_MOD_PATH (discussed in section 5).
|
||||
|
||||
clean
|
||||
|
|
@ -164,7 +164,7 @@ needed listing the files:
|
|||
NOTE: Further documentation describing the syntax used by kbuild is
|
||||
located in Documentation/kbuild/makefiles.txt.
|
||||
|
||||
The examples below demonstrate how-to create a build file for the
|
||||
The examples below demonstrate how to create a build file for the
|
||||
module 8123.ko, which is built from the following files:
|
||||
|
||||
8123_if.c
|
||||
|
|
@ -205,14 +205,14 @@ module 8123.ko, which is built from the following files:
|
|||
of the makefile. In the example, kbuild will only see the two
|
||||
assignments, whereas "make" will see everything except these
|
||||
two assignments. This is due to two passes made on the file:
|
||||
the first pass is by the "make" instance run on the
|
||||
command line; the second pass is by the kbuild system, which is
|
||||
the first pass is by the "make" instance run on the command
|
||||
line; the second pass is by the kbuild system, which is
|
||||
initiated by the parameterized "make" in the default target.
|
||||
|
||||
--- 3.2 Separate Kbuild File and Makefile
|
||||
|
||||
In newer versions of the kernel, kbuild will first look for a
|
||||
file named "Kbuild", and only if that is not found, will it
|
||||
file named "Kbuild," and only if that is not found, will it
|
||||
then look for a makefile. Utilizing a "Kbuild" file allows us
|
||||
to split up the makefile from example 1 into two files:
|
||||
|
||||
|
|
@ -288,8 +288,8 @@ module 8123.ko, which is built from the following files:
|
|||
--- 3.4 Building Multiple Modules
|
||||
|
||||
kbuild supports building multiple modules with a single build
|
||||
file. For example, if you want to build two modules, foo and
|
||||
bar, the kbuild lines would be:
|
||||
file. For example, if you wanted to build two modules, foo.ko
|
||||
and bar.ko, the kbuild lines would be:
|
||||
|
||||
obj-m := foo.o bar.o
|
||||
foo-y := <foo_srcs>
|
||||
|
|
@ -320,7 +320,7 @@ according to the following rule:
|
|||
To include a header file located under include/linux/, simply
|
||||
use:
|
||||
|
||||
#include <linux/modules.h>
|
||||
#include <linux/module.h>
|
||||
|
||||
kbuild will add options to "gcc" so the relevant directories
|
||||
are searched.
|
||||
|
|
@ -330,7 +330,7 @@ according to the following rule:
|
|||
External modules tend to place header files in a separate
|
||||
include/ directory where their source is located, although this
|
||||
is not the usual kernel style. To inform kbuild of the
|
||||
directory use either ccflags-y or CFLAGS_<filename>.o.
|
||||
directory, use either ccflags-y or CFLAGS_<filename>.o.
|
||||
|
||||
Using the example from section 3, if we moved 8123_if.h to a
|
||||
subdirectory named include, the resulting kbuild file would
|
||||
|
|
@ -390,11 +390,11 @@ according to the following rule:
|
|||
Modules which are included in the kernel are installed in the
|
||||
directory:
|
||||
|
||||
/lib/modules/$(KERNELRELEASE)/kernel
|
||||
/lib/modules/$(KERNELRELEASE)/kernel/
|
||||
|
||||
And external modules are installed in:
|
||||
|
||||
/lib/modules/$(KERNELRELEASE)/extra
|
||||
/lib/modules/$(KERNELRELEASE)/extra/
|
||||
|
||||
--- 5.1 INSTALL_MOD_PATH
|
||||
|
||||
|
|
@ -403,7 +403,7 @@ And external modules are installed in:
|
|||
installation path using the variable INSTALL_MOD_PATH:
|
||||
|
||||
$ make INSTALL_MOD_PATH=/frodo modules_install
|
||||
=> Install dir: /frodo/lib/modules/$(KERNELRELEASE)/kernel
|
||||
=> Install dir: /frodo/lib/modules/$(KERNELRELEASE)/kernel/
|
||||
|
||||
INSTALL_MOD_PATH may be set as an ordinary shell variable or,
|
||||
as shown above, can be specified on the command line when
|
||||
|
|
@ -413,14 +413,14 @@ And external modules are installed in:
|
|||
--- 5.2 INSTALL_MOD_DIR
|
||||
|
||||
External modules are by default installed to a directory under
|
||||
/lib/modules/$(KERNELRELEASE)/extra, but you may wish to locate
|
||||
modules for a specific functionality in a separate directory.
|
||||
For this purpose, use INSTALL_MOD_DIR to specify an alternative
|
||||
name to "extra."
|
||||
/lib/modules/$(KERNELRELEASE)/extra/, but you may wish to
|
||||
locate modules for a specific functionality in a separate
|
||||
directory. For this purpose, use INSTALL_MOD_DIR to specify an
|
||||
alternative name to "extra."
|
||||
|
||||
$ make INSTALL_MOD_DIR=gandalf -C $KDIR \
|
||||
M=$PWD modules_install
|
||||
=> Install dir: /lib/modules/$(KERNELRELEASE)/gandalf
|
||||
=> Install dir: /lib/modules/$(KERNELRELEASE)/gandalf/
|
||||
|
||||
|
||||
=== 6. Module Versioning
|
||||
|
|
@ -478,9 +478,9 @@ build.
|
|||
|
||||
Use a top-level kbuild file
|
||||
If you have two modules, foo.ko and bar.ko, where
|
||||
foo.ko needs symbols from bar.ko, then you can use a
|
||||
foo.ko needs symbols from bar.ko, you can use a
|
||||
common top-level kbuild file so both modules are
|
||||
compiled in the same build. Consider following
|
||||
compiled in the same build. Consider the following
|
||||
directory layout:
|
||||
|
||||
./foo/ <= contains foo.ko
|
||||
|
|
@ -491,10 +491,11 @@ build.
|
|||
#./Kbuild (or ./Makefile):
|
||||
obj-y := foo/ bar/
|
||||
|
||||
And executing:
|
||||
And executing
|
||||
|
||||
$ make -C $KDIR M=$PWD
|
||||
|
||||
Will then do the expected and compile both modules with
|
||||
will then do the expected and compile both modules with
|
||||
full knowledge of symbols from either module.
|
||||
|
||||
Use an extra Module.symvers file
|
||||
|
|
@ -512,10 +513,11 @@ build.
|
|||
Use "make" variable KBUILD_EXTRA_SYMBOLS
|
||||
If it is impractical to copy Module.symvers from
|
||||
another module, 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
|
||||
of files to KBUILD_EXTRA_SYMBOLS in your build file.
|
||||
These files will be loaded by modpost during the
|
||||
initialization of its symbol tables.
|
||||
|
||||
|
||||
=== 7. Tips & Tricks
|
||||
|
||||
--- 7.1 Testing for CONFIG_FOO_BAR
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user