Re: Purpose of 'legacy_boot' attribute

[Brian C. Lane]

On Tue, Oct 18, 2011 at 11:15:28PM -0600, Chris Murphy wrote:
> Is it correct that the parted 'legacy_boot' flag sets the partition attribute 
> "Legacy BIOS Bootable" bit? And is there any case where it would be 
> appropriate for it to be set for an EFI System partition?
> 
> I ask because I'm seeing Fedora 16 beta InstallDVD set this parted 
> 'legacy_boot' flag on an EFI System partition. But the LiveCD does not. That 
> discrepancy is a likely bug. However, I'm wondering which one is incorrect. 
> It doesn't seem like the EFI System partition should have this attribute set, 
> if indeed the flag sets the Legacy BIOS Bootable bit.

The primary use for legacy_boot is with the gptmbr bootloader, so yes it
doesn't really make sense to set it on an EFI system. I used it in
livecd-iso-to-disk when creating hybrid EFI/BIOS bootable USB sticks.

I was also just wondering if we (Fedora) should be setting legacy_boot
on /boot partitions instead of the boot flag, since the latter writes an EFI
system GUID to the partition type. 

-- 
Brian C. Lane | Anaconda Team | IRC: bcl #anaconda | Port Orchard, WA (PST8PDT)

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