I have determined that the installer splash-screen with the boot
choices menu is created from the file
/usr/share/live/build/bootloaders/isolinux/splash.svg
which has certain textual replacements made, and is then converted to a bitmap.
Copying that file to the live-build tree allows for the use of a
customised version and undergoes the same textual substitutions.
The textual replacements seem to be made by the script
/lib/live/build/binary_syslinux:235 (for all bootloaders?)
But it seems to get the wrong answer, in cases where a custom kernel is used.
_LINUX_VERSIONS="$(for _LINUX in chroot/boot/vmlinuz-* ; do chroot
chroot apt-cache policy $(basename ${_LINUX} | sed -e
's|vmlinuz-|linux-image-|') | awk '/Installed: / { print $2 }' ; done
| sort -Vru | tr "\n" " ")"
The splash-screen text on the image I am making says
"4.19.118-2+deb10u1" but as far as I can see that is not the name of
any kernel in my chroot.
But as sed and awk a mystery to me, and I am vague on bash, perhaps I
am misunderstanding the purpose of the line above. Or maybe that isn't
even the script used in the isolinux boot case?
Also:
It would be nice if this substitution could be used to put various
items from the lb config on the splash screen, such as
LB_ISO_APPLICATION (--iso-application) , LB_ISO_PUBLISHER
(--iso-publisher) etc.
Note: The docs on the --lb-iso** options suggest that the macros set
are different from what they really are:
"--lb-application
sets the APPLICATION field in the header of a resulting CD/DVD image
and defaults to "Debian Live" in debian mode, and "Ubuntu Live" in
ubuntu mode"
Whereas what is set is LB_ISO_APPLICATION
However the docs
(https://live-team.pages.debian.net/live-manual/html/live-manual/customizing-binary.en.html
) don't even mention the possibility of editing the splash.svg,
instead suggesting that it should be replaced by a static bitmap.
I have copy-pasted the extra field that I want into binary_syslinux on
my system, but I have a feeling that a better way can be found by
someone more knowledgable than me with sed and awk, whereby _ANY_
@STRING@ was substituted by $STRING so probably won't be making a
pull-request
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912
