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Re: USB media install has wrong partition

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Thomas,
Thank you for clarification on the layout, as it is in fact most helpful
in understanding GPT cruft.  As a Gentoo user, I can in fact boot
system-rescue-cd and Knoppix as EFI USB.  Sadly, this seems like one
more nail in the coffin of reasons I need to upgrade my PC.  I cannot
reproduce the boot error on a dell system either.

Thank you for your support and time.


On Sat, Sep 15, 2018 at 07:09:58PM +0200, Thomas Schmitt wrote:
> Hi,
> 
> John Roman wrote:
> > As I understand, a Protective MBR may be located at LBA 0 
> 
> In the case of the isohybrid partition layout of Matthew J. Garrett,
> which is used by Debian for i386 and amd64, the MBR is not protective.
> 
> A bit confusing can be the GPT partition table debris that follows the MBR.
> It is supposed to be ignored by any entity which cares about GPT specs.
> Matthew presented his layout at
>   http://mjg59.dreamwidth.org/11285.html
> He talks of Fedora ISOs. Debian joined that layout, but without HFS+
> filesystem.
> 
> 
> > is this what the live image does
> 
> From the view of EFI and many partition editors, Debian's ISO MBR
> effectively marks only one partition, the EFI partition, as entry number 2.
> 
> Entry number 1 has type 0x00 to avoid rejection by EFI due to partition 2
> sitting inside partition 1. UEFI 2.4, 5.2.1 specifies:
>   "A Partition Record that contains an OSType value of zero or a SizeInLBA
>    value of zero may be ignored."
> Partition 1 exists to mark the size of the ISO 9660 filesystem. It is not
> supposed to matter during booting. (BIOS boots by the MBR x86 machine code.)
> 
> 
> > my desktop (2012) does not seem to understand 0xEF...I wish I knew why.
> 
> If you have access to a running Debian System, then you could build a
> grub-mkrescue ISO, which will have a protective MBR and valid GPT.
> If it boots to a GRUB prompt, then we know that your machine would work
> with GPT.
> 
> Try to create it with these commands ("minimal/file" is just to have a
> directory and file, on which grub-mkrescue insists):
> 
>   sudo apt-get install grub-pc grub-efi-ia32-bin grub-efi-amd64-bin xorriso
>   mkdir minimal
>   echo hello >minimal/file
>   grub-mkrescue -o output.iso minimal
> 
> Put output.iso onto an USB stick, as you did with the Debian ISO.
> 
> -------
> 
> Another test proposal:
> 
> Knoppix 8.1 ISOs have a different MBR based partition layout than Fedora,
> Debian, et.al. If Knoppix 8.1 (or newer version) boots, then your
> firmware probably hates that Debian partition 1 encloses partition 2,
> despite its type 0x00.
> (Knoppix 8.0 has a partition layout like Debian, but with appended
> partition 3 of type 0x83. Knoppix 7 has no partition table at all.)
> 
> 
> Have a nice day :)
> 
> Thomas
> 

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Thread

USB media install has wrong partition John Roman <john@dev1ce.com> - 2018-09-15 04:30 +0200
  Re: USB media install has wrong partition Steve McIntyre <steve@einval.com> - 2018-09-15 05:20 +0200
    Re: USB media install has wrong partition John Roman <john@dev1ce.com> - 2018-09-15 17:20 +0200
    Re: USB media install has wrong partition John Roman <john@dev1ce.com> - 2018-09-15 17:40 +0200
  Re: USB media install has wrong partition "Thomas Schmitt" <scdbackup@gmx.net> - 2018-09-15 19:20 +0200
    Re: USB media install has wrong partition John Roman <john@dev1ce.com> - 2018-09-15 20:10 +0200
      Re: USB media install has wrong partition "Thomas Schmitt" <scdbackup@gmx.net> - 2018-09-15 20:40 +0200
        Re: USB media install has wrong partition mick crane <mick.crane@gmail.com> - 2018-09-16 09:10 +0200
          Re: USB media install has wrong partition "Thomas Schmitt" <scdbackup@gmx.net> - 2018-09-16 09:40 +0200
            Re: USB media install has wrong partition mick crane <mick.crane@gmail.com> - 2018-09-16 10:10 +0200
            Re: USB media install has wrong partition David <bouncingcats@gmail.com> - 2018-09-16 10:20 +0200
              Re: USB media install has wrong partition "Thomas Schmitt" <scdbackup@gmx.net> - 2018-09-16 13:10 +0200
            Re: USB media install has wrong partition David <bouncingcats@gmail.com> - 2018-09-16 10:30 +0200
  Re: USB media install has wrong partition Pascal Hambourg <pascal@plouf.fr.eu.org> - 2018-09-15 20:20 +0200
    Re: USB media install has wrong partition Wayne Sallee <Wayne@WayneSallee.com> - 2018-09-15 20:40 +0200
    Re: USB media install has wrong partition "Thomas Schmitt" <scdbackup@gmx.net> - 2018-09-15 20:50 +0200

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