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Re: USB media install has wrong partition



Correct sir, I am having issues installing to an asus sabertooth 990
motherboard. namely, the boot override menu fails to recognize the EFI
media as a proper EFI bootable target.

As I understand, a Protective MBR may be located at LBA 0 (i.e., the first logical block)
of the disk if it is using the GPT disk layout. The Protective MBR precedes the GUID Partition Table
Header to maintain compatibility with existing tools that do not understand GPT partition
structures. is this what the live image does?

its perhaps my hypothesis that this protective mbr entry is stymying
attempts to boot a true EFI partition.  the specification ive referenced
is from 2017, and my motherboard is from 2012.
http://www.uefi.org/sites/default/files/resources/UEFI%20Spec%202_7_A%20Sept%206.pdf

0xEF is covered, as you rightly confirmed, in section 5.2.2.



On Sat, Sep 15, 2018 at 03:39:35AM +0100, Steve McIntyre wrote:
> john@dev1ce.com wrote:
> >greetings,
> >the USB install media for netinst and live both create a dos partition
> >table on dd, and cp.  This will result in media that can only be booted
> >legacy, as GPT is a requirement for EFI boot.
> 
> Sorry, that's incorrect. It's perfectly valid in the UEFI spec for an
> EFI System Partition to be a partition with type 0xEF in an
> msdos-style partition table, particularly for removable media. Are you
> having problems booting on a particular machines?
> 
> -- 
> Steve McIntyre, Cambridge, UK.                                steve@einval.com
> "Further comment on how I feel about IBM will appear once I've worked out
>  whether they're being malicious or incompetent. Capital letters are forecast."
>  Matthew Garrett, http://www.livejournal.com/users/mjg59/30675.html


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