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Re: Announcing xorriso-0.1.6

Bill Davidsen <davidsen@tmr.com> wrote:

> This has been on my "someday list" for a while, does it have the 
> capability of taking a bootable image, letting me change the non-boot 
> files, and then giving me another burnable image? I'm thinking Linux 
> install disks with the extras and upgrades added, to simplify creation. 
> While I know how to make bootable media, from scratch if need be, I 
> don't much enjoy the steps.  :-(

This will not work without non-artficial intelligence as you need tricks to 
make a CD boot on every BIOS.

The best way to re-create a bootable CD is to manually find the boot image 
first. This can be done by calling "isodebug":

isodebug -i /tmp/sol-nv-b87-x86-dvd.iso 
ISO-9660 image created at Mon Apr  7 12:32:02 2008

Cmdline: 'mkisofs 2.01 -b boot/grub/stage2_eltorito -c .catalog -no-emul-boot -boot-load-size 4 -boot-info-table -relaxed-filenames -l -ldots -r -N -d -D -V SOL_11_X86 -o .../solarisdvd.iso .../solarisdvd.product'

As yoou see, the boot image is "boot/grub/stage2_eltorito", however only the 
first 2048 bytes of this file are announced in the ElTorito header:

isoinfo  -d -i /tmp/sol-nv-b87-x86-dvd.iso 
CD-ROM is in ISO 9660 format
System id: Solaris
Volume id: SOL_11_X86
Volume set id: 
Publisher id: 
Data preparer id: 
Copyright File id: 
Abstract File id: 
Bibliographic File id: 
Volume set size is: 1
Volume set sequence number is: 1
Logical block size is: 2048
Volume size is: 1984486
El Torito VD version 1 found, boot catalog is in sector 10559
NO Joliet present
Rock Ridge signatures version 1 found
Eltorito validation header:
    Hid 1
    Arch 0 (x86)
    ID ''
    Key 55 AA
    Eltorito defaultboot header:
        Bootid 88 (bootable)
        Boot media 0 (No Emulation Boot)
        Load segment 0
        Sys type 0
        Nsect 4
        Bootoff 2940 10560

What you see with this output is that the file /boot/grub/stage2_eltorito
starts at Sector # 10560.

As ElTorito only announces 2048 bytes from:

-r--r--r--   1    0    0          133008 Apr  2 2008 [  10560 00]  stage2_eltorito 

(this output if from isoinfo  -i /tmp/sol-nv-b87-x86-dvd.iso -lR)

it is obvious that any automated attempt to re-create a bootable DVD from the 
Solaris install DVD will not work. BTW: Linux CDs/DVDs look very similar.


 EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
       js@cs.tu-berlin.de                (uni)  
       schilling@fokus.fraunhofer.de     (work) Blog: http://schily.blogspot.com/
 URL:  http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily

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