Re: [PATCH 1/3] MdeModulePkg/PartitionDxe: Put the UDF check ahead of MBR

["Gao, Zhichao" <zhichao.gao@intel.com>]

Ray,

The MBR info is correct. The order change is to avoid the MBR being checked before UDF/ISO 9660 check.
That is why I make the patch #3 in the last of the patch set.

Thanks,
Zhichao

> -----Original Message-----
> From: Ni, Ray <ray.ni@intel.com>
> Sent: Tuesday, August 11, 2020 4:04 PM
> To: Gao, Zhichao <zhichao.gao@intel.com>; devel@edk2.groups.io
> Cc: Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A <hao.a.wu@intel.com>;
> Gary Lin <glin@suse.com>; Andrew Fish <afish@apple.com>
> Subject: RE: [PATCH 1/3] MdeModulePkg/PartitionDxe: Put the UDF check ahead
> of MBR
> 
> Zhichao,
> Can you also add notes in the commit message describing that for some ISOs
> (better with more specific ISO info), the MBR information is not correct?
> 
> Thanks,
> Ray
> 
> 
> > -----Original Message-----
> > From: Gao, Zhichao <zhichao.gao@intel.com>
> > Sent: Tuesday, August 11, 2020 2:43 PM
> > To: devel@edk2.groups.io
> > Cc: Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A
> > <hao.a.wu@intel.com>; Ni, Ray <ray.ni@intel.com>; Gary Lin
> > <glin@suse.com>; Andrew Fish <afish@apple.com>
> > Subject: [PATCH 1/3] MdeModulePkg/PartitionDxe: Put the UDF check
> > ahead of MBR
> >
> > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2823
> >
> > Refer to UEFI spec 2.8, Section 13.3.2, a block device should be
> > scanned as below order:
> > 1. GPT
> > 2. ISO 9660 (El Torito) (UDF should aslo be here) 3. MBR 4. no
> > partition found
> > Note: UDF is using the same boot method as CD, so put it in the same
> > priority with ISO 9660.
> >
> > This would also solve the issue that ISO image with MBR would be treat
> > as MBR device instead of CD/DVD. That would make the behavior of the
> > image boot different.
> >
> > Cc: Jian J Wang <jian.j.wang@intel.com>
> > Cc: Hao A Wu <hao.a.wu@intel.com>
> > Cc: Ray Ni <ray.ni@intel.com>
> > Cc: Gary Lin <glin@suse.com>
> > Cc: Andrew Fish <afish@apple.com>
> > Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
> > ---
> >  MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c | 10 +++++++++-
> >  1 file changed, 9 insertions(+), 1 deletion(-)
> >
> > diff --git a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
> > b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
> > index 6a43c3cafb..473e091320 100644
> > --- a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
> > +++ b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
> > @@ -35,11 +35,19 @@ EFI_DRIVER_BINDING_PROTOCOL
> > gPartitionDriverBinding = {
> >
> >  //
> >  // Prioritized function list to detect partition table.
> > +// Refer to UEFI Spec 13.3.2 Partition Discovery, the block device //
> > +should be scanned in below order:
> > +// 1. GPT
> > +// 2. ISO 9660 (El Torito) (or UDF)
> > +// 3. MBR
> > +// 4. no partiton found
> > +// Note: UDF is using a same method as booting from CD-ROM, so put it
> along
> > +//        with CD-ROM check.
> >  //
> >  PARTITION_DETECT_ROUTINE mPartitionDetectRoutineTable[] = {
> >    PartitionInstallGptChildHandles,
> > -  PartitionInstallMbrChildHandles,
> >    PartitionInstallUdfChildHandles,
> > +  PartitionInstallMbrChildHandles,
> >    NULL
> >  };
> >
> > --
> > 2.21.0.windows.1
>