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Diffstat (limited to 'Documentation/kbuild/modules.txt')
| -rw-r--r-- | Documentation/kbuild/modules.txt | 46 |
1 files changed, 23 insertions, 23 deletions
diff --git a/Documentation/kbuild/modules.txt b/Documentation/kbuild/modules.txt index a2a178da02f..2e7702e94a7 100644 --- a/Documentation/kbuild/modules.txt +++ b/Documentation/kbuild/modules.txt @@ -24,7 +24,7 @@ In this document you will find information about: --- 6.1 INSTALL_MOD_PATH --- 6.2 INSTALL_MOD_DIR === 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 --- 7.3 Symbols from another external module === 8. Tips & Tricks @@ -63,14 +63,15 @@ when building an external module. For the running kernel use: make -C /lib/modules/`uname -r`/build M=`pwd` - For the above command to succeed the kernel must have been built with - modules enabled. + For the above command to succeed, the kernel must have been + built with modules enabled. To install the modules that were just built: 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 @@ -89,13 +90,13 @@ when building an external module. Same functionality as if no target was specified. See description above. - make -C $KDIR M=$PWD modules_install + make -C $KDIR M=`pwd` modules_install Install the external module(s). Installation default is in /lib/modules/<kernel-version>/extra, but may be prefixed with INSTALL_MOD_PATH - see separate chapter. - make -C $KDIR M=$PWD clean + make -C $KDIR M=`pwd` clean Remove all generated files for the module - the kernel source directory is not modified. @@ -129,23 +130,22 @@ when building an external module. To make sure the kernel contains the information required to build external modules the target 'modules_prepare' must be used. - 'module_prepare' solely exists as a simple way to prepare - a kernel for building external modules. + 'module_prepare' exists solely as a simple way to prepare + a kernel source tree for building external modules. Note: modules_prepare will not build Module.symvers even if - CONFIG_MODULEVERSIONING is set. - Therefore a full kernel build needs to be executed to make - module versioning work. + CONFIG_MODULEVERSIONING is set. Therefore a full kernel build + needs to be executed to make module versioning work. --- 2.5 Building separate files for 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 - modules. + This works equally well for the kernel, a module and even for + external modules. Examples (module foo.ko, consist of bar.o, baz.o): make -C $KDIR M=`pwd` bar.lst make -C $KDIR M=`pwd` bar.o make -C $KDIR M=`pwd` foo.ko make -C $KDIR M=`pwd` / - + === 3. Example commands @@ -177,7 +177,7 @@ Then, to install the module use the following command: M=`pwd` \ 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. 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 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 -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 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. Consider the following example: - + | +- src/complex_main.c | +- hal/hardwareif.c | +- hal/include/hardwareif.h +- include/complex.h - + To build a single module named complex.ko, we then need the following kbuild file: @@ -462,12 +462,12 @@ Module.symvers contains a list of all exported symbols from a kernel build. Sample: 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 Module.symvers serves two purposes: 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 @@ -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. During the MODPOST step, a new Module.symvers file will be written containing all exported symbols that were not defined in the kernel. - + --- 7.3 Symbols from another external module 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 ./bar/ <= contains the bar module The top-level Kbuild file would then look like: - + #./Kbuild: (this file may also be named Makefile) 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 containing the sum of all symbols defined and not part of the kernel. - + === 8. Tips & Tricks --- 8.1 Testing for CONFIG_FOO_BAR |