Ubuntu – How to bypass “Try it / Install” screen when booting from USB Live Session? (without installing in the USB)

live-usb

This has been asked several times already (I found it here, here and here), but basically everyone simply recommend to perform a full install to the USB stick. But I do need it to stay as a LIVE session, not a "full install on USB", for a number of reasons (the most important one being that using Live session I can easily install Ubuntu using the desktop icon)

So, my constraints for skipping the Welcome Screen (and automatically choose "Try Ubuntu" option) are:

  • It must actually be the Ubuntu Live session (or as close to the default as possible). Same software selection (gparted is present in live sessions, gimp is not, for example), user (name and ID), behavior (no login screen, no password for sudo, to name a few), no GRUB, etc. That rules out an Ubuntu full install on USB.

  • It must be able to install Ubuntu in the computer (while full install requires the ISO file, an additional USB stick, and the hassle of Startup Disk Creator)

  • If possible, to be as fast as the "text-based launcher" (the one you have when you press a key right after the kernel loads)

  • It must be completely automatic, unattended from boot to desktop.

  • Select a different language than default. It can be a hard-corded selection (actually, it must, since boot itself shall be fully unattended). But preferably be easily changed ("easily" as in editing a config file then rebooting)

Is it possible?

The proposed (great) solutions that I've ruled out so far are:

  • Installing Ubuntu in the USB stick (for all of the above mentioned reasons)

  • Remove Ubiquity package (it removes the ability to install the system from that USB as well)

  • Ubuntu Customization Kit (ubk): several limitations and caveats, and its not even in the repos

  • Remastersys / LiLi: its the same as full direct USB install, only customized.

An ideal solution would be something like "create USB sick using Startup Disk Creator, then open it and remove / edit / add file(s) xxx, yyy, zzz"

Best Answer

This guide was made for Ubuntu (Gnome). It works for Kubuntu (KDE) too, with a few exceptions

I've been able to get the Live CD boot straight into a Live session without timeout or fancy menu, optionally with a language pack installed.

Live USB (16.04)

  1. Mount the USB with Ubuntu installed in it
  2. Backup the file syslinux/syslinux.cfg. We will modify it so we need to replace it back if something goes wrong.
  3. Open the following files under syslinux directory: syslinux.cfg and txt.cfg
  4. Delete (or comment) everything in syslinux.cfg.

  5. The txt.cfg file has the default GRUB menu entries. Copy the live one to syslinux.cfg:

    default live
label live
menu label ^Try Ubuntu without installing
kernel /casper/vmlinuz.efi
append file=/cdrom/preseed/ubuntu.seed boot=casper cdrom-detect/try-usb=true persistent noprompt floppy.allowed_drive_mask=0 ignore_uuid initrd=/casper/initrd.lz quiet splash --

  6. You can add any specific kernel parameters needed for your device in the append line.

  7. Save isolinux.cfg and boot your system using the USB. It will boot straight to the desktop now.

Live USB (13.10)

  1. Mount the USB with Ubuntu installed in it
  2. Backup the file isolinux/isolinux.cfg. We will modify it so we need to replace it back if something goes wrong.
  3. Open the following files under isolinux directory: isolinux.cfg and txt.cfg
  4. Delete everything in isolinux.cfg.

  5. The txt.cfg file has the default GRUB menu entries. Copy the live one to isolinux.cfg:

    default live
label live
menu label ^Try Ubuntu without installing
kernel /casper/vmlinuz.efi
append file=/cdrom/preseed/ubuntu.seed boot=casper cdrom-detect/try-usb=true persistent noprompt floppy.allowed_drive_mask=0 ignore_uuid initrd=/casper/initrd.lz quiet splash --

  6. You can add any specific kernel parameters needed for your device in the append line.

  7. Save isolinux.cfg and boot your system using the USB. It will boot straight to the desktop now.

[source]

Live USB (11.04)

  1. Go to the root folder of your Live USB
  2. Enter the syslinux directory
  3. Make the syslinux.cfg file writeable

  4. Replace the contents of the file syslinux.cfg with:

    default live
label live
  say Booting an Ubuntu Live session...
  kernel /casper/vmlinuz
  append  file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash noprompt --
  5. Optional: localize the system (see below)

Live CD

  1. If you've a Live CD in your CD drive, mount it. Otherwise, if you've an ISO file available, mount it on /media/cdrom by running the next command in a terminal (replace the name of the .iso file accordingly):

    sudo mount -o loop,ro ubuntu-11.04-desktop-amd64.iso /media/cdrom
  2. Create a temporary directory in which the CD contents can be stored, say ~/live-cd (mkdir ~/live-cd)
  3. Copy the contents of the CD to the folder ~/live-cd/iso (cp -r /media/cdrom ~/live-cd/iso)
  4. Since the Live CD is not needed anymore, it can be unmounted (sudo umount /media/cdrom)
  5. Open the ~/live-cd/iso folder (cd ~/live-cd/iso)
  6. Enter the isolinux directory (cd isolinux)
  7. Make the isolinux.cfg file writable (chmod u+w isolinux.cfg)

  8. Replace the contents of the file isolinux.cfg with:

    default live
label live
  say Booting an Ubuntu Live session...
  kernel /casper/vmlinuz
  append  file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --
  9. Optional: localize the system (see below)

  10. Open a terminal and run:

    cd ~/live-cd
chmod u+w iso/isolinux/isolinux.bin
mkisofs -r -V "Ubuntu Live session" -cache-inodes -J -l -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -o ubuntu-11.04-live-amd64.iso iso
  11. The new iso will be available at ~/live-cd/ubuntu-11.04-live-amd64.iso. To save space, the ~/live-cd/iso directory can be removed. (rm -rf ~/live-cd/iso)
  12. Now burn the ubuntu-11.04-live-amd64.iso file on a CD if needed.

Localize Ubuntu (translations)

If you want the system in the languages English, Spanish, Portuguese, Xhosa or Simplified Chinese, you've just to add the locale= boot option with en, es, pt, xh or zh to the append line as in:

... quiet splash locale=pt --

Otherwise, if you do not want to modify the file containing the root file system (filesystem.squashfs) and do not mind hacking around, continue reading.

Open a terminal and navigate to the ~/live-cd/iso directory and put the code from http://pastebin.com/VTdt9WFZ in a file (name it install-locale) and run it.

This script mounts the filesystem.squashfs, retrieves version information of the language packs from it, downloads the packages and put those in the directory locale-hack. Next, a script is created that installs the language packages on boot time. To make that work, the script also modifies the syslinux.cfg or isolinux.cfg file to apply these changes.

You'll be asked for a locale, enter something like nl or de. The script is not that clever to understand things like Dutch or German. Afterwards, the file can be removed

The terminal commands that should be executed:

cd ~/live-cd/iso
wget http://pastebin.com/raw.php?i=VTdt9WFZ -O install-locale
bash install-locale
rm install-locale

Note that adding language pack can cause the generated .iso file to be bigger than 700MB which won't fit on a CD. For virtual machines however, it suffices. This hack has as a side-effect that Plymouth does not work (i.e. you do not get a fancy boot screen), but at least the system is translated when logging in. Otherwise, you had to install language-pack-gnome-* manually.

References

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