[PATCH 2/5] filetype: add GPT support

Jean-Christophe PLAGNIOL-VILLARD plagnioj at jcrosoft.com
Fri Feb 15 05:47:32 EST 2013


On 08:43 Fri 15 Feb     , Johannes Stezenbach wrote:
> On Thu, Feb 14, 2013 at 11:08:55PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > On 20:17 Thu 14 Feb     , Sascha Hauer wrote:
> > > On Thu, Feb 14, 2013 at 06:05:07PM +0100, Johannes Stezenbach wrote:
> > > > On Thu, Feb 14, 2013 at 05:53:23PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > > > > On 17:36 Thu 14 Feb     , Sascha Hauer wrote:
> > > > > > On Thu, Feb 14, 2013 at 04:52:24PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > > > > > > GPT need to be check before MBR
> ...
> > > > > > > +	if (bufsize >= 520 && strncmp(&buf8[512], "EFI PART", 8) == 0)
> > > > > > > +		return filetype_gpt;
> > > > > > > +
> > > > > > 
> > > > > > The list is sorted by size, so please move this below:
> > > > > on purpose
> > > > > 
> > > > > EFI need to be detect before mbr
> > > > 
> > > > IMHO the check is too simple, it will give false positive if
> > > > GPT is replaced by DOS MBR and not zeroed out.  Need to check
> > > > for protective MBR.
> > > 
> > > So is_fat_or_mbr() should test if the MBR is a protective MBR and return
> > > false in this case?
> > 
> > no as the efi is more I do the check in efi.c protective bit and right type
> > 
> > I move the code to filetype
> > 
> > but efi need to be before MBR as you could have both for retro compatibility
> 
> Yes, Wikipedia says Apple Bootcamp creates hybrid MBR.
> But if you run fdisk to create DOS MBR it will only
> replace the first sector and leave the GPT alone.
> Thus I think for usability it is important to check MBR
> (for 0xAA55 marker and one of the part types must be 0xee).
Do not take Wikipedia for the bible

We implemenb the EFI spec

Best Regards,
J.
> 
> Johannes



More information about the barebox mailing list