Re: ISO installer image: GPT versus MBR partitions

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

Florian Pelz wrote:
> florian@florianmacbook ~ [env]$ grub-mkrescue -o output.iso minimal
> --xorriso=./grub-mkrescue-sed.sh
> grub-mkrescue: warning: Your xorriso doesn't support `--grub2-boot-info'.
> Some features are disabled. Please use xorriso 1.2.9 or later..
>
> and yields no output.iso for me.  Note that xorriso actually has
> version 1.5.0.

Does the script offer x-permission ?
(Shame on me for not thinking of this in my download instructions.)

If so, what do you get from

  ./grub-mkrescue-sed.sh -as mkisofs -help 2>&1 | fgrep grub2-boot-info

If it says

  --grub2-boot-info           Patch boot image at byte 2548

then i wonder why grub-mkrescue is not satisfied in
  http://git.savannah.gnu.org/cgit/grub.git/tree/util/grub-mkrescue.c#n608


I wrote:
> > So programs like /sbin/isosize can tell the image size even when the
> > ISO has already been copied to USB stick.

> Sounds like this could be used to get a checksum or maybe GPG
> verification of a USB drive that supposedly contains the iso.

That's what this property is advised for in Debian's CD FAQ.
One can read trailing garbage not only from USB sticks but also from
most DVD types.
(The layout with nested partitions obsoletes the cleanliness
 considerations about partition start at LBA 0.)


Have a nice day :)

Thomas