Re: [Bug-xorriso] [bug #46716] Protective MBR partition is not marked as bootable

[Andrei Borzenkov]

19.12.2015 21:39, Thomas Schmitt пишет:
> 
> I assume that its MBR lets any decent EFI ignore the GPT:
> 
>   MBR partition table:   N Status  Type        Start       Blocks
>   MBR partition      :   1   0x00  0xee            1           63

Those implementations I am aware of will skip MBR if protective entry is
found. None of them also actually checks partition size. I am aware of
one case where incorrect partition size caused problems (libparted,
although I think it was caused by vendor patch); neither edk2 not GRUB
nor Linux care for it.

>   MBR partition      :   2   0x80  0x07           64          272
>   MBR partition      :   3   0x00  0xef          336         5760
>   MBR partition      :   4   0x00  0x07         6096        26708
>   MBR partition path :   3  /efi.img
> 
> Isn't 0xee a misnomer now that you decided for MBR ?

This looks like "normal" hybrid MBR
(http://www.rodsbooks.com/gdisk/hybrid.html).

> 
> 
> Nevertheless, your overlapping layout would have the appeal of
> giving a mountable partition:
> 
>   MBR partition table:   N Status  Type        Start       Blocks
>   MBR partition      :   1   0x80  0x00            0        32804
>   MBR partition      :   2   0x00  0xef          336         5760
> 
> It would travel on the ticket that EFI shall ignore MBR partition
> type 0x00.
> 

I'm not sure where this assumptions comes from. EFI does not say
anything about other partition types, besides that other partition
entries /should/ not be defined. So any additional partition besides
protective is strictly speaking against EFI standard.