gpart rewrites pmbr in a way which breaks Win 7 EFI bootloader

[Andrey V. Elsukov]

On 09.08.2012 12:57, Lawrence Stewart wrote:
> After identifying the cause of the problem and a workaround (please see the README.txt at the above
> URL for full details and pre/post gpart dumps of the MBR+GPT), I have the following questions:
> 
> - Should gpart be writing 0x80 (active) in the protective MBR entry?

AFAIK, this was added because some BIOS could not boot without it.

>   - Why is Windows EFI bootloader so sensitive to 0x80 in pmbr?

This question you should ask to the Microsoft. :)

> - Should gpart be silently rewriting the protective MBR entry at all when only asked to make changes
> to the GPT?

The PMBR is part of GPT metadata described in the UEFI spec. So, I think it can.

-- 
WBR, Andrey V. Elsukov



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