how to modify a livecd

[bill pemberton]

i would like to modify a live cd to have a root and user account and to
mount a home directory for the user.  i have taken a fedora 12 iso, broken
it apart, made my changes and need to create the bootable iso image.  that
is where i'm running into a problem.  i have tried using the grub
stage2_eltorito file but that didn't work (maybe the command i copied was
incorrect).  i have thought about snagging the first sector (i think that is
right) of a good iso and merging that with what i have but i have a feeling
that won't work.  from what i can tell i need a boot image file to use but i
have not been able to locate one of the correct size (per the mkisofs man
page) in the files i have for the iso.  the docs i have been reading today
so far haven't indicated where i can find this file and web searches haven't
been very fruitful.  since i'm not changing the packages but just the
contents of the passwd, shadow, and fstab i would think this would be an
easy thing to accomplish.  i have looked into using a persistent image but
after waiting nearly an hour for the image to be written (using
livecd-creator) i felt that that must not be working correctly either.  i
can get an sd card to boot via writing the iso using dd and so far that is
the only way to get an sd card or usb drive to boot.  so i must be missing
something with this livecd-creator (and i think the livecd-iso-to-disk
script as well).

the main idea is to have a bootable livecd on an sdcard, use a usb drive for
the home dir for a user and this way have a dual boot machine and be able to
test different distros from time to time.

would someone mind pointing me in the right direction to accomplish this
goal?

-- 
wapembe

[Jasper Hartline]

I don't know about you but when I have a directory, which is to be made into
a LiveCD I just use mkisofs with the isolinux.bin
using:
            /usr/bin/mkisofs -quiet -R -pad -V <volume ID> -b
boot/isolinux/isolinux.bin -c boot/isolinux/boot.cat -p myname -x lost+found
-no-emul-boot -boot-load-size 4 -boot-info-table -o isoimage dir

The isolinux.bin and boot.cat need to be changed to specify your location of
these files if syslinux is installed.
Using a SSD card though all you would need to do to create one is
grub-install /dev/yourdevice

If you are only making an image I am not sure if livecd-iso-to-disk handles
that but it is simple..
with a program c-section I use it just creates two loopback files and uses
kpartx to map them, then I grub install to the mapper device and close the
filehandle.

This will create a LiveUSB image you can put on any USB flash or SSD card I
assume if you preload the SSD controller card modules.
Not sure how SSD works exactly, it is flash basically, just might not use
USB protocol.

On Tue, Mar 23, 2010 at 5:52 PM, bill pemberton <wapembe(a)gmail.com&gt; wrote:

>  i would like to modify a live cd to have a root and user account and
> to
>  mount a home directory for the user.  i have taken a fedora 12 iso, broken
>  it apart, made my changes and need to create the bootable iso image.
>

[Joey Boggs]

On 03/23/2010 08:52 PM, bill pemberton wrote:
>  i would like to modify a live cd to have a root and user account and
>
>  to mount a home directory for the user.  i have taken a fedora 12 iso, 
>  broken it apart, made my changes and need to create the bootable iso 
>  image.  that is where i'm running into a problem.  i have tried using 
>  the grub stage2_eltorito file but that didn't work (maybe the command 
>  i copied was incorrect).  i have thought about snagging the first 
>  sector (i think that is right) of a good iso and merging that with 
>  what i have but i have a feeling that won't work.  from what i can 
>  tell i need a boot image file to use but i have not been able to 
>  locate one of the correct size (per the mkisofs man page) in the files 
>  i have for the iso.  the docs i have been reading today so far haven't 
>  indicated where i can find this file and web searches haven't been 
>  very fruitful.  since i'm not changing the packages but just the 
>  contents of the passwd, shadow, and fstab i would think this would be 
>  an easy thing to accomplish.  i have looked into using a persistent 
>  image but after waiting nearly an hour for the image to be written 
>  (using livecd-creator) i felt that that must not be working correctly 
>  either.  i can get an sd card to boot via writing the iso using dd and 
>  so far that is the only way to get an sd card or usb drive to boot.  
>  so i must be missing something with this livecd-creator (and i think 
>  the livecd-iso-to-disk script as well).
>
>  the main idea is to have a bootable livecd on an sdcard, use a usb 
>  drive for the home dir for a user and this way have a dual boot 
>  machine and be able to test different distros from time to time.
>
>  would someone mind pointing me in the right direction to accomplish 
>  this goal?
>
>  -- 
>  wapembe
>
>
>  --
>  livecd mailing list
>  livecd(a)lists.fedoraproject.org
>  https://admin.fedoraproject.org/mailman/listinfo/livecd 
If putting the iso back together is the biggest problem try the patch I 
sent earlier to the list for edit-livecd. It will mount it and present 
you into the chroot'ed file system and them repackage it all for you as 
an edited iso file.

Here's a link to the script if you want to give it a shot

http://fedorapeople.org/~jboggs/edit-livecd.py

Then you can use livecd-iso-to-disk to write it to disk

[David Huff]

On 03/23/2010 09:57 PM, Joey Boggs wrote:
>  If putting the iso back together is the biggest problem try the patch
> I
>  sent earlier to the list for edit-livecd. It will mount it and present
>  you into the chroot'ed file system and them repackage it all for you as
>  an edited iso file.
>
>  Here's a link to the script if you want to give it a shot
>
>  http://fedorapeople.org/~jboggs/edit-livecd.py
>
>  Then you can use livecd-iso-to-disk to write it to disk 

Have the maintainers of livecd-tools had a chance to look at this 
script? Do you think that we can include this into the livecd-tools 
package?

-D