live usb straight to desktop

[Goh Lip]

On 05/02/2011 04:30 PM, Ariszló wrote:
> Booting Ubuntu from a live usb stick, how do you skip language
> selection and the screen that asks you whether you want to try Ubuntu
> or install it?
>
> Is there a config file to edit that allows you to boot straight into
> Unity live session using your preferred language and keyboard layout?
>
> I have asked this at http://ubuntuforums.org/showthread.php?t=1746638
> but the forum has so high traffic that it is unlikely that the topic
> will be noticed.
>

Ariszlo, I'll try to answer your question without telling you what to 
do. You decide. First the preliminaries.


As Alan has mentioned, it may be better, in most cases, to install 
direct to the usb stick (with grub booting there); to boot up only iso, 
there too are many choices, unetbootin and pendrive linux. I find 
unetbootin and pendrive have several drawbacks, notably ...nevermind.
And there is the one I prefer, booting up using grub2. So I'll just 
explain this.


After downloading a *bootable* livecd - and this does not include the 
ubuntu *alternate* install cd, put it an any directory, I prefer to have 
a uniquely named directory (you shall see why). So lets call the iso 
livelive.iso and the directory /isotope in /, not /home (though you can 
do that, but the path name is longer and I don't want to type so much 
:)  ).

Let's start with casper based livecd, the one that  ubuntu or 
ubuntu-based livecd iso uses.


To boot this up, just have an entry in your grub2.cfg .

menuentry "Iso - casper" {
search --set=root -f /isotope/livelive.iso
loopback loop /isotope/livelive.iso
linux (loop)/casper/vmlinuz boot=casper 
iso-scan/filename=/isotope/livelive.iso noeject noprompt quiet splash
initrd (loop)/casper/initrd.lz
}



To boot that iso in usb, create 2 (or more) partitions in the usb, 1 to 
put your grub2 boot in it and the other to contain the iso's.
So create the directory /isotope in one, put the livelive.iso in it and 
have the grub2 boot file in the other and set to boot /dev/sdb.

To have 'persistent' so that you can keep your changes, like nvidia, 
language, firefox, new installed applications, etc., create a partition, 
label it 'casper-rw' and for the grub2 linux line above include 
'persistent' (without quote marks) in it.



For non-casper livecd, the usual entry will look like this...

menuentry "many others iso" {
search --set=root -f /isotope/livelive.iso
loopback loop /isotope/livelive.iso
  linux (loop)/boot/grmlsmall/linux26 findiso=/isotope/livelive.iso 
apm=power-off lang=us vga=791 boot=live nomce noeject noprompt --
  initrd (loop)/boot/grmlsmall/initrd.gz
}

or this...

or ....


You get the idea. It may be very different and depends on the developers 
of that distro, sometimes they imbed some passkeys or preseeds (just add 
these in the linux line) or some requirements to have some extracted 
files to be in /isotope.

All except casper do not allow to save changes (sorry, puppy linux 
allows that but surreptitiously create a partition for it).

However, you can see (usually) what to do with a livecd by mounting it 
and see what's required (mount -o loop livelivecd.iso /media/seeiso) and 
recheck if initrd file is initrd.lz, initrd.gz or just initrd.img.
Same goes with vmlinuz files or just plain linux26.

Hope this helps.

Regards - Goh Lip