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Custom Live CD and splash boot

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coyotus just gave me this link:

--- Citer ---I found my answer in backtrack linux forums. And since I set up the bounty I would like to explain a little bit what my problem was and how it got solved.

I was trying to customize Ubuntu/KUbuntu 10.04 Live CD and I couldn't figure out how to change the splash screen that shows after isolinux.

Changing playmouth theme available on the extracted filesystem.squashfs at /lib/plymouth/themes/ didn't do the trick.

So I found this message stating that the splash screen files used by the Live CD to boot reside in casper/initrd.lz.

So, if you are interested to know how to extract and reconstruct this file, read the end of the section 5.7.1. Quote:
    To unpack the initrd.lz file, you need to do this:

# cd extract-cd/casper
# mkdir lztempdir
# cd lztempdir
# lzma -dc -S .lz ../initrd.lz | cpio -imvd --no-absolute-filenames

    And to re-create the initrd.lz file:

# cp ../initrd.lz ../inird.lz.orig
# find . | cpio --quiet --dereference -o -H newc | lzma -7 > ../initrd.lz
--- Fin de citation ---

While using Ubuntu Builder to customize to Ubuntu Openbox spin, I stumbled upon another idea:

--- Citer ---Create the Cd Image Directory and Populate it


A. You will need a kernel and an initrd that was built with the Casper scripts. Grab them from your chroot. Use the current version. Note that before 9.10, the initrd was in gz not lz format...

--- Code: ---cp chroot/boot/vmlinuz-2.6.**-**-generic image/casper/vmlinuz

cp chroot/boot/initrd.img-2.6.**-**-generic image/casper/initrd.lz
--- Fin du code ---

--- Fin de citation ---

This idea comes from the fact that the commands listed in the former post don't work for the initrd.lz which is in the "ISO/casper"directory, and fails with "prematured end of file", which means the archive is corrupted. (And it does work on an initrd.lz from another version of Ubuntu). So I have to change this archive anyhow.

Ok, here is a problem solved : the initrd.lz found in Ubuntu Precise is not a real lzma archive, but a .gz archive : gzip.

Then to extract it it first needs to be renamed:

--- Code: ---mv initrd.lz initrd.gz
--- Fin du code ---

then gunzipped:

--- Code: ---gunzip initrd.gz
--- Fin du code ---

then we get a file having for name "initrd" and then:

--- Code: ---mkdir tmp2
--- Fin du code ---

--- Code: ---cd tmp2/
--- Fin du code ---

--- Code: ---cpio -id < ../initrd
--- Fin du code ---

the output will look like "16524 blocks"

All this should be done as root, if we intend to reconstruct the initrd afterwards.

More here:

I am having a look here, about plymouth theming:

I am not going to learn about coding, I was just seeking for information about the "/isolinux/bootlogo" file in the iso, because grep tells me there is a "jpg" file inserted inside the init file located in that bootlogo archive.

I keep also this one which I'll point to while asking questions at some ubuntu chans:

From another thread as of last October:

--- Citer ---Hi,

The first boot image matter will be solved and also an error message after some updates, due to the fact I was re-using directly the plymouth-theme-ubuntu-text files direcly to make my own instead of creating a new one. I will try this method instead:

Not with the image, but copying the file from the Ubuntu Plymouth text theme into a new directory having for name bento-theme-text, changing the name of the file and some of the content, then use the command lines from that page:

--- Code: ---sudo update-alternatives --install /lib/plymouth/themes/default.plymouth default.plymouth /lib/plymouth/themes/simple/simple.plymouth 100
--- Fin du code ---

--- Code: ---sudo update-alternatives --config default.plymouth
--- Fin du code ---

--- Code: ---sudo update-initramfs -u
--- Fin du code ---

Of course I will not need sudo because I am already in a chroot, the one provided by the Ubuntu Builder terminal.

--- Fin de citation ---

This seems to solve the recognition of a theme installed by hand in the /lib/plymouth directory.


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