Documentation/admin-guide/README.rst

3 Linux kernel release 6.x <http://kernel.org/>
8 kernel, and what to do if something goes wrong.
39   Linux has also been ported to itself. You can now run the kernel as a
53    these typically contain kernel-specific installation notes for some
57    your kernel.
59 Installing the kernel source
62  - If you install the full sources, put the kernel tarball in a
68    Replace "X" with the version number of the latest kernel.
71    incomplete) set of kernel headers that are used by the library header
73    whatever the kernel-du-jour happens to be.
77    newer patch files, enter the top level directory of the kernel source
90    directly to the base 6.x kernel.  For example, if your base kernel is 6.0
92    and 6.0.2 patches. Similarly, if you are running kernel version 6.0.2 and
97    Alternatively, the script patch-kernel can be used to automate this
98    process.  It determines the current kernel version and applies any
101      linux/scripts/patch-kernel linux
104    kernel source.  Patches are applied from the current directory, but
126 Build directory for the kernel
129    When compiling the kernel, all output files will per default be
130    stored together with the kernel source code.
135      kernel source code: /usr/src/linux-6.x
136      build directory:    /home/name/build/kernel
138    To configure and build the kernel, use::
141      make O=/home/name/build/kernel menuconfig
142      make O=/home/name/build/kernel
143      sudo make O=/home/name/build/kernel modules_install install
148 Configuring the kernel
229      "make kvm_guest.config"   Enable additional options for kvm guest kernel
232      "make xen.config"   Enable additional options for xen dom0 guest kernel
235      "make tinyconfig"  Configure the tiniest possible kernel.
237    You can find more information on using the Linux kernel config tools
242     - Having unnecessary drivers will make the kernel bigger, and can
246     - A kernel with math-emulation compiled in will still use the
248       never get used in that case.  The kernel will be slightly larger,
252     - The "kernel hacking" configuration details usually result in a
253       bigger or slower kernel (or both), and can even make the kernel
255       break bad code to find kernel problems (kmalloc()).  Thus you
259 Compiling the kernel
265  - Do a ``make`` to create a compressed kernel image. It is also possible to do
267    install script recognised by the kernel's installer. Most popular
274  - If you configured any of the parts of the kernel as ``modules``, you
277  - Verbose kernel compile/build output:
279    Normally, the kernel build system runs in a fairly quiet mode (but not
280    totally silent).  However, sometimes you or other kernel developers need
290  - Keep a backup kernel handy in case something goes wrong.  This is
293    backup of the modules corresponding to that kernel, as well.  If you
294    are installing a new kernel with the same version number as your
295    working kernel, make a backup of your modules directory before you
298    Alternatively, before compiling, use the kernel config option
299    "LOCALVERSION" to append a unique suffix to the regular kernel version.
302  - In order to boot your new kernel, you'll need to copy the kernel
304    to the place where your regular bootable kernel is found.
306  - Booting a kernel directly from a storage device without the assistance
309    which allows the motherboard to boot directly to the kernel.
330  - If you use LILO the kernel images are specified in the file /etc/lilo.conf.
331    The kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or
332    /boot/bzImage. To use the new kernel, save a copy of the old image and copy
334    loading map! If you don't, you won't be able to boot the new kernel image.
337    to edit /etc/lilo.conf to specify an entry for your old kernel image
345    kernel image, use your bootloader's boot options where appropriate. No need
346    to recompile the kernel to change these parameters.
348  - Reboot with the new kernel and enjoy.
354 If you have problems that seem to be due to kernel bugs, please follow the
357 Hints on understanding kernel bug reports are in
358 'Documentation/admin-guide/bug-hunting.rst'. More on debugging the kernel
359 with gdb is in 'Documentation/dev-tools/gdb-kernel-debugging.rst' and