Boot kernel CD ok, but cannot boot LiveUSB (fat32/squashfs)

[vanjeje]

Hello,

I want to use my wife's old notebook without USB BIOS support (USB is totally inactive at startup) to start a LiveUSB stick. I do not want to install Ubuntu on the

I have created a Boot CD with a kernel and some modules, using tutorials, BootUSBFromCD (https://help.ubuntu.com/community/BootFromUSB#Booting%20the%20kernel%20from%20a%20bo otable%20CD), and especially CD de Boot pour les amateurs de cambouis (http://fausse-piste.net/piste1/spip.php?article157).
This is great, I have even added some modules to support my Pcmcia USB2 card (initially only USB1 of the computer was usable).

But this seems to work only on a complete Ubuntu installation on the USB Stick. On the LiveUSB startup disk created from Ubuntu 8.10 LiveCD, there are only the files in a fat32 partition. Adding squashfs in the modules for the Boot CD is not enough. There must be a special way of booting in this case.
How can I have my Boot CD with USB activation start the squashed system on the LiveUSB stick ?

(hints : currently, the startup process last stage ends with

Begin: Running /scripts/local-premount ...
Done.
Begin: Running /scripts/local-bottom ...
Done.
Done.
Begin: Running /scripts/init-bottom ...
mount: mounting /root/dev on /dev/.static/dev failed: No such file or directory
Done.
mount: mount /sys on /root/sys failed: No such file or directory

Target filesystem doesn't have /sbin/init.
No init found. Try passing init= bootarg.

BusyBox ... (ash)
...
(initramfs)

In the /root I can find LiveUSB files, for instance /root/casper with the squashfs system in it...

Thanks in advance for any piece of advise.

[vanjeje]

Well, I looked at the netboot configuration, since it is similar.
There is just an additional "boot=casper" for grub's kernel load line, in order to boot the LiveUSB (created from Ubuntu 8.10 Desktop LiveCD utility).

Sum up : in order to create a kernel boot CD, this tutorial (http://fausse-piste.net/piste1/spip.php?article157).

I made two "lsmod", before and after putting in my Pcmcia USB2 card with my USB stick, and a "diff" to see which modules where added. I also added squashfs and aufs, and some others, I wonder which ones are really required.
My modules, in /etc/initramfs-tools/modules :

usbcore
sd_mod
yenta_socket
rsrc_nonstatic
pcmcia_core
ehci_hcd
uhci_hcd
ohci_hcd
usb-storage
scsi_mod
fat
vfat
loop
squashfs
aufs
exportfs

my grub menu.lst :

title Ubuntu
root (cd)
kernel /boot/vmlinuz-usb root=/dev/sdb1 boot=casper ro quiet splash
initrd /boot/initrd-usb.img
boot

If you add "persistent" to the kernel line, and you have a labelled "casper-rw" partition (will it also work on the "casper-rw" file created by the LiveUSB utility?), you will be able to keep your changes on the LiveCD session.
I hope I will be able to start my liveUSB on multiple computers, with or without USB BIOS support.

It seems somehow magic to me, so I would appreciate some useful documentation on how linux is starting.

[martinbaselier]

Today I had to do some repartitioning on my laptop and I found my ODD stopped working (must have happened sometime in the last few months.) but anyway I had to boot from a usb-stick, which my BIOS does not support.

So I pressed c in grub and used my usb-stick created with ubuntu 8.10.
root (hd1,0)
chainloader +1
boot
Which basically threats the device as if it was bootable.

And I had the same problem as vanjeje. the stick seemed to boot normally but I ended in a intramfs-prompt.

I removed everything from the usb-stick (including hidden files and then used a iso from xubuntu 8.04 on the stick. same problem. Erased everything again and now used the iso from ubuntu 8.10 and it worked.

Not really a technical insight, but maybe it will help you solve the problem.

FYI:
When I created the image from the live CD after booting from HDD on my ubuntu intrepid desktop-pc I got an error and it did not finish creating the stick (I think, I have not tested booting from it that way)