Linux Kernel Makefile Explained

1. What is Makefile in Linux kernel?
2. What is Kbuild in kernel?
3. Why Makefile is used in Linux?
4. How Linux kernel is compiled?
5. How do I run a kernel module?
6. How do I make a .KO file?
7. How will get the driver added into the kernel what are Kconfig files?
8. Where is the Linux kernel config file?
9. What does OBJ M mean?
10. How do I run a Makefile in Unix?
11. Why do we use Makefile?
12. Is Makefile a shell script?

What is Makefile in Linux kernel?

A Makefile is only responsible for building objects in its own directory. Files in subdirectories should be taken care of by Makefiles in these subdirs. The build system will automatically invoke make recursively in subdirectories, provided you let it know of them. To do so, obj-y and obj-m are used.

What is Kbuild in kernel?

Kbuild refers to different kinds of makefiles: Makefile is the top makefile located in source root. . config is the kernel configuration file. arch/$(ARCH)/Makefile is the arch makefile, which is the supplement to the top makefile.

Why Makefile is used in Linux?

Makefile is a program building tool which runs on Unix, Linux, and their flavors. It aids in simplifying building program executables that may need various modules. To determine how the modules need to be compiled or recompiled together, make takes the help of user-defined makefiles.

How Linux kernel is compiled?

The procedure to build (compile) and install the latest Linux kernel from source is as follows: Grab the latest kernel from kernel.org. Verify kernel. Untar the kernel tarball.

How do I run a kernel module?

The procedure to compile and run a kernel module is as follows:

1. Modify the makefile by replacing every occurrence of helloWorld and kernelRead by the names of the modules you wish to create.
2. compile the modules by running make in the directory where the modules reside. ...
3. Now become superuser by typing.

How do I make a .KO file?

Short answer: you can't. A . ko file is more than just a compiled version of your driver source. The kernel build system includes some extra information for instance (compiler version, module dependencies, ...).

How will get the driver added into the kernel what are Kconfig files?

How to add your linux driver module in a kernel

1. 1). Create your module directory in /kernel/drivers.
2. 2). Create your file inside /kernel/drivers/hellodriver/ and add below functions and save it.
3. 3). Create empty Kconfig file and Makefile in /kernel/drivers/hellodriver/
4. 4). Add below entries in Kconfig.
5. 5). Add below entries in Makefile.
6. 6). ...
7. 7). ...
8. 8).

Where is the Linux kernel config file?

The Linux kernel configuration is usually found in the kernel source in the file: /usr/src/linux/. config .

What does OBJ M mean?

1. From the Linux kernel documentation for obj-m: "$(obj-m) specifies object files that are built as kernel modules.". There isn't an obj-m+ . The + is part of the += operator to append to a variable. It can also be used to append subdirectories which will be entered recursively. –

How do I run a Makefile in Unix?

As paxdiablo said make -f pax.mk would execute the pax.mk makefile, if you directly execute it by typing ./pax.mk, then you would get syntax error. Also you can just type make if your file name is makefile/Makefile .

Why do we use Makefile?

Compiling the source code files can be tiring, especially when you have to include several source files and type the compiling command every time you need to compile. Makefiles are the solution to simplify this task. Makefiles are special format files that help build and manage the projects automatically.

Is Makefile a shell script?

put a command in a file and it is a shell script. a Makefile however is a very clever bit of scripting (in it's own language to all extents) that compiles an accompanying set of source code into a program.