Re: Doubts about Debian8.1 DVD ppc64el image

[Ramon Medeiros <ramonn@linux.vnet.ibm.com>]

On 06/11/2015 05:23 PM, Thomas Schmitt wrote:
> Hi,
>
> > Our algorithm is
> > failing to discover if this iso[1] is bootable.
> I am curious to learn about the expectations of that algorithm.
>
> The ISO looks like being bootable via CHRP.
>  From my cheatsheet
>    http://bazaar.launchpad.net/~libburnia-team/libisofs/scdbackup/view/head:/doc/boot_sectors.txt
> "CHRP is marked by an MBR partition entry of type 0x96 spanning the whole
>   ISO 9660 image."
>
> I cannot spot "ppc64el" in
> http://cdimage.debian.org/mirror/cdimage/archive/latest-oldstable/powerpc/iso-cd/
> Old-stable "powerpc" was made by genisoimage rather than xorriso.
> It has an Apple Partition Map additionally to the CHRP MBR,
> probably pointing to a HFS filesystem.
>
> So if your algorithm looks for magic number {'E','R'}
> at the start of the file, that would be what's missing in "ppc64el"
> ISOs. (Together with the HFS, of course.)
>
> --------------------------------------------------------------------
> In case this does not yet explain the riddle:
>
> What was the most recent ISO which passed your tests ?
>
> Can you run GNU xorriso >= 1.3.8 on that ISO ?
> (Debian's xorriso is still at 1.3.2, i fear.)
>
>    xorriso -indev ...iso \
>            -report_el_torito plain \
>            -report_system_area plain \
>            -pvd_info
Here is the output of xorriso:

root@debian:/home/ramonn/xorriso-1.4.0# ./xorriso/xorriso -indev 
/root/debian-8.1.0-ppc64el-DVD-1.iso -report_el_torito plain 
-report_system_area plain -pvd_info
GNU xorriso 1.4.0 : RockRidge filesystem manipulator, libburnia project.

xorriso : NOTE : Loading ISO image tree from LBA 0
xorriso : UPDATE : 9554 nodes read in 1 seconds
Drive current: -indev '/root/debian-8.1.0-ppc64el-DVD-1.iso'
Media current: stdio file, overwriteable
Media status : is written , is appendable
Boot record  : (system area only) , MBR CHRP cyl-align-off
Media summary: 1 session, 2290620 data blocks, 4474m data, 3339m free
Volume id    : 'Debian 8.1.0 ppc64el 1'
xorriso : NOTE : No El Torito information was loaded
System area options: 0x00000600
System area summary: MBR CHRP cyl-align-off
ISO image size/512 : 9162480
Partition offset   : 0
MBR heads per cyl  : 0
MBR secs per head  : 0
MBR partition table:   N Status  Type        Start       Blocks
MBR partition      :   1   0x80  0x96            0      9162480
Drive current: -indev '/root/debian-8.1.0-ppc64el-DVD-1.iso'
PVD address  : 16s
Volume Id    : Debian 8.1.0 ppc64el 1
Volume Set Id:
Publisher Id :
Preparer Id  : XORRISO-1.3.6 2014.04.08.180000, LIBISOBURN-1.3.6, 
LIBISOFS-1.3.6, LIBBURN-1.3.6
App Id       :
System Id    :
CopyrightFile:
Abstract File:
Biblio File  :
Creation Time: 2015060622352300
Modif. Time  : 2015060622352300
Expir. Time  : 0000000000000000
Eff. Time    : 0000000000000000
root@debian:/home/ramonn/xorriso-1.4.0#

> Have a nice day :)
>
> Thomas

--

Ramon Nunes Medeiros
Kimchi Developer
Linux Technology Center Brazil
IBM Systems & Technology Group
Phone : +55 19 2132 7878
ramonn@br.ibm.com