docs: admin-guide: Update bootloader and installation instructions

Updates the bootloader and installation instructions in
admin-guide/README.rst to align with modern practices.

Details of Changes:

 - Added guidance on using EFISTUB for UEFI/EFI systems.
 - Noted that LILO is no longer in active development and provides
   alternatives.
 - Kept LILO instructions but marked as Legacy LILO Instructions.
   Suggest removal in future patch.

Signed-off-by: Hunter Chasens <hunter.chasens18@ncf.edu>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
[jc: repaired added whitespace warnings]
Link: https://lore.kernel.org/r/20240207171007.45405-1-hunter.chasens18@ncf.edu
This commit is contained in:
Hunter Chasens 2024-02-07 12:10:07 -05:00 committed by Jonathan Corbet
parent 7da8bdbf8f
commit 3a5f1c3d83

View File

@ -262,9 +262,11 @@ Compiling the kernel
- Make sure you have at least gcc 5.1 available.
For more information, refer to :ref:`Documentation/process/changes.rst <changes>`.
- Do a ``make`` to create a compressed kernel image. It is also
possible to do ``make install`` if you have lilo installed to suit the
kernel makefiles, but you may want to check your particular lilo setup first.
- Do a ``make`` to create a compressed kernel image. It is also possible to do
``make install`` if you have lilo installed or if your distribution has an
install script recognised by the kernel's installer. Most popular
distributions will have a recognized install script. You may want to
check your distribution's setup first.
To do the actual install, you have to be root, but none of the normal
build should require that. Don't take the name of root in vain.
@ -301,32 +303,51 @@ Compiling the kernel
image (e.g. .../linux/arch/x86/boot/bzImage after compilation)
to the place where your regular bootable kernel is found.
- Booting a kernel directly from a floppy without the assistance of a
bootloader such as LILO, is no longer supported.
- Booting a kernel directly from a storage device without the assistance
of a bootloader such as LILO or GRUB, is no longer supported in BIOS
(non-EFI systems). On UEFI/EFI systems, however, you can use EFISTUB
which allows the motherboard to boot directly to the kernel.
On modern workstations and desktops, it's generally recommended to use a
bootloader as difficulties can arise with multiple kernels and secure boot.
For more details on EFISTUB,
see "Documentation/admin-guide/efi-stub.rst".
If you boot Linux from the hard drive, chances are you use LILO, which
uses the kernel image as specified in the file /etc/lilo.conf. The
kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or
/boot/bzImage. To use the new kernel, save a copy of the old image
and copy the new image over the old one. Then, you MUST RERUN LILO
to update the loading map! If you don't, you won't be able to boot
the new kernel image.
- It's important to note that as of 2016 LILO (LInux LOader) is no longer in
active development, though as it was extremely popular, it often comes up
in documentation. Popular alternatives include GRUB2, rEFInd, Syslinux,
systemd-boot, or EFISTUB. For various reasons, it's not recommended to use
software that's no longer in active development.
Reinstalling LILO is usually a matter of running /sbin/lilo.
You may wish to edit /etc/lilo.conf to specify an entry for your
old kernel image (say, /vmlinux.old) in case the new one does not
work. See the LILO docs for more information.
- Chances are your distribution includes an install script and running
``make install`` will be all that's needed. Should that not be the case
you'll have to identify your bootloader and reference its documentation or
configure your EFI.
After reinstalling LILO, you should be all set. Shutdown the system,
Legacy LILO Instructions
------------------------
- If you use LILO the kernel images are specified in the file /etc/lilo.conf.
The kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or
/boot/bzImage. To use the new kernel, save a copy of the old image and copy
the new image over the old one. Then, you MUST RERUN LILO to update the
loading map! If you don't, you won't be able to boot the new kernel image.
- Reinstalling LILO is usually a matter of running /sbin/lilo. You may wish
to edit /etc/lilo.conf to specify an entry for your old kernel image
(say, /vmlinux.old) in case the new one does not work. See the LILO docs
for more information.
- After reinstalling LILO, you should be all set. Shutdown the system,
reboot, and enjoy!
If you ever need to change the default root device, video mode,
etc. in the kernel image, use your bootloader's boot options
where appropriate. No need to recompile the kernel to change
these parameters.
- If you ever need to change the default root device, video mode, etc. in the
kernel image, use your bootloader's boot options where appropriate. No need
to recompile the kernel to change these parameters.
- Reboot with the new kernel and enjoy.
If something goes wrong
-----------------------