manual: add section about the images we released.

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
neox: - fixed duplicate see with @pxref in "(@ref{GNU Boot images} for
        more details)" and "the @pxref{GNU Boot images types} subsection.",
	"will be documented in the @ref{GNU Boot images} section below"
      - found "See the @pxref{boot software} section to understand",
        "described in the previous subsection (@pxref{GNU resolution graphics",
        "described in the previous subsection (@pxref{GNU Boot images types}).",
        "(see @pxref{boot software} for more details)."
Acked-by: Adrien Bourmault <neox@gnu.org>
This commit is contained in:
Denis 'GNUtoo' Carikli 2024-11-24 18:10:52 +01:00 committed by Adrien 'neox' Bourmault
parent 5affc6ec91
commit 2a36deb4a0
Signed by: neox
GPG Key ID: 57BC26A3687116F6
1 changed files with 145 additions and 3 deletions

View File

@ -395,8 +395,8 @@ below.
GNU Boot supports the GPUs that are present in the various laptops it
supports with 100% free software. Some consideration apply while
booting, but so far once booted these GPU are known to works well on
tested computers.
booting (@pxref{GNU Boot images} for more details), but so far once
booted these GPU are known to works well on tested computers.
In addition for the non-laptop computers, it also supports the builtin
AST graphics in the KGPE-D16 and KCMA-D8 with 100% free software, but
@ -479,7 +479,8 @@ these and welcome contributions in this area.
While GNU Boot should be able to boot almost any GNU/Linux
distribution, but in some cases some configuration might be needed by
the GNU Boot user.
the GNU Boot user. The cases that do and don't require configuration
from the user will be documented in @ref{GNU Boot images} below.
Even if some cases require some configuration, GNU Boot makes sure to
provide at least one way to boot free GNU/Linux distributions (see
@ -525,6 +526,147 @@ Also if you want to do such tests, you can open a bug report on the
GNU Boot bug tracker at
@url{https://savannah.gnu.org/bugs/?group=gnuboot}.
@node GNU Boot images
@section GNU Boot images
@cindex flash images
@cindex image files
In computers people are most familar with, like laptops, the boot
software resides in a memory chip inside the mainboard (@pxref{boot
software} for more details).
GNU Boot provide @dfn{image files} which are files that replace the
content of these memory chip.
These files are similar to
@uref{https://en.wikipedia.org/wiki/Disk_image,disk images},
@uref{https://en.wikipedia.org/wiki/ISO_image,ISO images}, or
@uref{https://en.wikipedia.org/wiki/ROM_image,ROM images}.
We also sometime refer to the flash image files as @dfn{flash images}.
@node GNU Boot images types
@subsection GNU Boot images types
For a given computer, GNU Boot provides several images with different
software in it. This enable the users to choose between:
@itemize
@item Two boot software: GRUB or SeaBIOS
(@acronym{BIOS, Basic Input/Output System} implementation)
@item Various keyboard layouts (colemak, deqwertz, esqwerty,
frazerty, frdvbepo, itqwerty, svenska, trqwerty, ukdvorak, ukqwerty,
usdvorak, usqwerty).
@item Low resolution or high resolution graphics.
@end itemize
If you are a less technical user or helping one, or don't have much
time to configure things, it is a good idea to choose an image with
GRUB, and a keyboard layout of your choice (the resolution is not very
important, but using high resolution looks nicer) as the image with
GRUB doesn't require to do any configuration in the distributions you
want to boot.
Otherwise here are the advantages/disadvantages of each combinaison:
@itemize
@item GRUB with high resolution graphics: Images with GRUB
usually don't require the user to do any configuration of the
distribution. More technical users can also use that to customize the
way the system boots for more security or to support unsual boot
configurations (that are not typically supported by graphical
installers of GNU/Linux distributions), however these more advanced
configurations also come with their set of limitations.
@item SeaBIOS with text-only low resolution: It implements
@acronym{BIOS, Basic Input/Output System} compatibility, so it is very
similar to a nonfree @acronym{BIOS, Basic Input/Output System} but it
require users to modify some settings inside the distribution they
use, otherwise the distribution still boots but usually has a black
screen during the boot (which can be problematic to diagnose a
non-booting distribution). The low resolution increase compatibility
with various software that are typically run at boot like memtest86+
(a software that detects broken RAM chips).
@item GRUB with text-only low resolution: Since these images
boot with GRUB, they also don't require any configuration of the
distribution and more technical users can also use them to customize
the way the system boots. Compared to GRUB images with high resolution
graphics:
@itemize
@item the text is bigger and that there is no background picture
@item since on most supported computers, GRUB images can
also load and run SeaBIOS (there is a menu entry for
it), having a text-only low resolution increase the
compatibility with various boot software.
@end itemize
@item SeaBIOS with high resolution graphics:
Since these images boot with SeaBIOS they also implement some
@acronym{BIOS, Basic Input/Output System} compatibility, but they also
require users to modify some settings inside the distribution they
use. Compared with SeaBIOS images with text-only low resolution:
@itemize
@item they are less compatible with various boot software. This
can be useful for testing if you contribute to some boot
software.
@item since on most supported computers, SeaBIOS images can also
load and run GRUB (there is a menu entry for it when
pressing the 'ESC' key at boot), having high resolution
graphics can make GRUB look nicer.
@end itemize
@end itemize
@node GNU Boot images naming
@subsection GNU Boot images naming
Images for specific computers can be found on
@uref{https://ftp.gnu.org/gnu/gnuboot/,the GNU Boot download area} or
in the release/roms directory if you built GNU Boot from source
yourself.
For a given release (or release candidate) like GNU Boot 0.1-rc3, you
can find such files inside the 'roms' directory like
@url{https://ftp.gnu.org/gnu/gnuboot/gnuboot-0.1-rc3/roms/} for GNU
Boot 0.1-rc3.
Inside you have archive files like
@option{gnuboot-0.1-rc3_x200_8mb.tar.xz} that are specific to a
specific computer (here the ThinkPad X200 with 8MiB flash chip).
Inside each archive files, there are many smaller files that are flash
images. @xref{boot software} to understand what a flash image is.
The flash image files correspond to the configurations described in
the @ref{GNU Boot images types}.
So for instance if we have an image named
@option{grub_x200_8mb_corebootfb_usqwerty.rom}, it is meant for a
ThinkPad X200 with 8MiB flash chip, and it uses the GRUB software to
boot, and it is configured to use a QWERTY keyboard layout.
If the image contains @option{seabios} in its file name instead of
@option{grub}, it uses the SeaBIOS software to boot.
The @option{corebootfb} in the file name correspond to the high
resolution graphics described in the previous subsection (@ref{GNU
Boot images types}).
If instead the file has @option{txtmode} in its name, this corresponds
to the text-only low resolution that was also described in the
previous subsection (@ref{GNU Boot images types}).
@node Helping GNU Boot
@chapter Helping GNU Boot