Radix cross Linux

How to Build External Modules
-----------------------------

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.

Radix cross Linux provides a 'kernel-source' package installed here.

This kernel source not ready for build modules out-of-tree because Radix cross Linux
provides only cross-compiled packages.

To prepare kernel source you have to do following:

    $ cd /usr/src/@KERNEL_SOURCE@
    $ make oldconfig
    $ make modules_prepare

 If you are using a Radix cross Linux distribution kernel,
there will be a 'kernel-source' package for the kernel you are running provided by
Radix cross Linux distribution.

This will make sure the kernel contains the information required. The target 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_MODVERSIONS is set;
therefore, a full kernel build needs to be executed to make module versioning work.


Command Syntax
--------------

The command to build an external module is:

    $ 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

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


For mode details please look at
  https://www.kernel.org/doc/html/latest/kbuild/modules.html
page.