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kbuild: fixup Documentation/kbuild/modules.txt

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Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
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Robert P. J. Day 2006-09-21 09:39:41 -04:00 committed by Sam Ravnborg
parent da7c04083c
commit 2e99f3190f
1 changed files with 23 additions and 23 deletions
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Documentation/kbuild/modules.txt
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@ -24,7 +24,7 @@ In this document you will find information about:
--- 6.1 INSTALL_MOD_PATH --- 6.1 INSTALL_MOD_PATH
--- 6.2 INSTALL_MOD_DIR --- 6.2 INSTALL_MOD_DIR
=== 7. Module versioning & Module.symvers === 7. Module versioning & Module.symvers
--- 7.1 Symbols fron the kernel (vmlinux + modules) --- 7.1 Symbols from the kernel (vmlinux + modules)
--- 7.2 Symbols and external modules --- 7.2 Symbols and external modules
--- 7.3 Symbols from another external module --- 7.3 Symbols from another external module
=== 8. Tips & Tricks === 8. Tips & Tricks
@ -63,14 +63,15 @@ when building an external module.
For the running kernel use: For the running kernel use:
make -C /lib/modules/`uname -r`/build M=`pwd` make -C /lib/modules/`uname -r`/build M=`pwd`
For the above command to succeed the kernel must have been built with For the above command to succeed, the kernel must have been
modules enabled. built with modules enabled.
To install the modules that were just built: To install the modules that were just built:
make -C <path-to-kernel> M=`pwd` modules_install make -C <path-to-kernel> M=`pwd` modules_install
More complex examples later, the above should get you going. More complex examples will be shown later, the above should
be enough to get you started.
--- 2.2 Available targets --- 2.2 Available targets
@ -89,13 +90,13 @@ when building an external module.
Same functionality as if no target was specified. Same functionality as if no target was specified.
See description above. See description above.
make -C $KDIR M=$PWD modules_install make -C $KDIR M=`pwd` modules_install
Install the external module(s). Install the external module(s).
Installation default is in /lib/modules/<kernel-version>/extra, Installation default is in /lib/modules/<kernel-version>/extra,
but may be prefixed with INSTALL_MOD_PATH - see separate but may be prefixed with INSTALL_MOD_PATH - see separate
chapter. chapter.
make -C $KDIR M=$PWD clean make -C $KDIR M=`pwd` clean
Remove all generated files for the module - the kernel Remove all generated files for the module - the kernel
source directory is not modified. source directory is not modified.
@ -129,23 +130,22 @@ when building an external module.
To make sure the kernel contains the information required to To make sure the kernel contains the information required to
build external modules the target 'modules_prepare' must be used. build external modules the target 'modules_prepare' must be used.
'module_prepare' solely exists as a simple way to prepare 'module_prepare' exists solely as a simple way to prepare
a kernel for building external modules. a kernel source tree for building external modules.
Note: modules_prepare will not build Module.symvers even if Note: modules_prepare will not build Module.symvers even if
CONFIG_MODULEVERSIONING is set. CONFIG_MODULEVERSIONING is set. Therefore a full kernel build
Therefore a full kernel build needs to be executed to make needs to be executed to make module versioning work.
module versioning work.
--- 2.5 Building separate files for a module --- 2.5 Building separate files for a module
It is possible to build single files which are part of a module. It is possible to build single files which are part of a module.
This works equal for the kernel, a module and even for external This works equally well for the kernel, a module and even for
modules. external modules.
Examples (module foo.ko, consist of bar.o, baz.o): Examples (module foo.ko, consist of bar.o, baz.o):
make -C $KDIR M=`pwd` bar.lst make -C $KDIR M=`pwd` bar.lst
make -C $KDIR M=`pwd` bar.o make -C $KDIR M=`pwd` bar.o
make -C $KDIR M=`pwd` foo.ko make -C $KDIR M=`pwd` foo.ko
make -C $KDIR M=`pwd` / make -C $KDIR M=`pwd` /
=== 3. Example commands === 3. Example commands
@ -177,7 +177,7 @@ Then, to install the module use the following command:
M=`pwd` \ M=`pwd` \
modules_install modules_install
If one looks closely you will see that this is the same commands as If you look closely you will see that this is the same command as
listed before - with the directories spelled out. listed before - with the directories spelled out.
The above are rather long commands, and the following chapter The above are rather long commands, and the following chapter
@ -311,7 +311,7 @@ following files:
Include files are a necessity when a .c file uses something from other .c Include files are a necessity when a .c file uses something from other .c
files (not strictly in the sense of C, but if good programming practice is files (not strictly in the sense of C, but if good programming practice is
used). Any module that consists of more than one .c file will have a .h file used). Any module that consists of more than one .c file will have a .h file
for one of the .c files. for one of the .c files.
- If the .h file only describes a module internal interface, then the .h file - If the .h file only describes a module internal interface, then the .h file
shall be placed in the same directory as the .c files. shall be placed in the same directory as the .c files.
@ -368,13 +368,13 @@ directory and therefore need to deal with this in their kbuild file.
handle this too. handle this too.
Consider the following example: Consider the following example:
| |
+- src/complex_main.c +- src/complex_main.c
| +- hal/hardwareif.c | +- hal/hardwareif.c
| +- hal/include/hardwareif.h | +- hal/include/hardwareif.h
+- include/complex.h +- include/complex.h
To build a single module named complex.ko, we then need the following To build a single module named complex.ko, we then need the following
kbuild file: kbuild file:
@ -462,12 +462,12 @@ Module.symvers contains a list of all exported symbols from a kernel build.
Sample: Sample:
0x2d036834 scsi_remove_host drivers/scsi/scsi_mod 0x2d036834 scsi_remove_host drivers/scsi/scsi_mod
For a kernel build without CONFIG_MODVERSIONING enabled, the crc For a kernel build without CONFIG_MODVERSIONS enabled, the crc
would read: 0x00000000 would read: 0x00000000
Module.symvers serves two purposes: Module.symvers serves two purposes:
1) It lists all exported symbols both from vmlinux and all modules 1) It lists all exported symbols both from vmlinux and all modules
2) It lists the CRC if CONFIG_MODVERSION is enabled 2) It lists the CRC if CONFIG_MODVERSIONS is enabled
--- 7.2 Symbols and external modules --- 7.2 Symbols and external modules
@ -479,7 +479,7 @@ Module.symvers contains a list of all exported symbols from a kernel build.
the external module is being built, this file will be read too. the external module is being built, this file will be read too.
During the MODPOST step, a new Module.symvers file will be written During the MODPOST step, a new Module.symvers file will be written
containing all exported symbols that were not defined in the kernel. containing all exported symbols that were not defined in the kernel.
--- 7.3 Symbols from another external module --- 7.3 Symbols from another external module
Sometimes, an external module uses exported symbols from another Sometimes, an external module uses exported symbols from another
@ -499,7 +499,7 @@ Module.symvers contains a list of all exported symbols from a kernel build.
./foo/ <= contains the foo module ./foo/ <= contains the foo module
./bar/ <= contains the bar module ./bar/ <= contains the bar module
The top-level Kbuild file would then look like: The top-level Kbuild file would then look like:
#./Kbuild: (this file may also be named Makefile) #./Kbuild: (this file may also be named Makefile)
obj-y := foo/ bar/ obj-y := foo/ bar/
@ -521,7 +521,7 @@ Module.symvers contains a list of all exported symbols from a kernel build.
build is finished, a new Module.symvers file is created build is finished, a new Module.symvers file is created
containing the sum of all symbols defined and not part of the containing the sum of all symbols defined and not part of the
kernel. kernel.
=== 8. Tips & Tricks === 8. Tips & Tricks
--- 8.1 Testing for CONFIG_FOO_BAR --- 8.1 Testing for CONFIG_FOO_BAR