Re: question about a compressed Ffs3 file inside FFS2 filesystem

[Sean Brogan <sean.brogan@microsoft.com>]

Liming,

Good catch not sure how that happened. Unfortunately now the problem doesn't make sense.  The code should have IsFfs3Fv = True and the debug message that indicates the code path which ignores the section should not get executed.  I'll look at it again today as the problem still exists, just my analysis is incorrect.  

Current workaround is to make sure FFS2 sizes and guids are used everywhere so a problem with FFS3 is lurking somewhere.  

Thanks
Sean


> -----Original Message-----
> From: Gao, Liming [mailto:liming.gao@intel.com]
> Sent: Thursday, October 20, 2016 1:27 AM
> To: Sean Brogan <sean.brogan@microsoft.com>; edk2-devel@lists.01.org
> Subject: RE: [edk2] question about a compressed Ffs3 file inside FFS2 filesystem
> 
> Sean:
>   In MdePkg.dec, gEfiFirmwareFileSystem2Guid and
> gEfiFirmwareFileSystem3Guid are defined below.
>   gEfiFirmwareFileSystem2Guid     = { 0x8c8ce578, 0x8a3d, 0x4f1c, { 0x99, 0x35,
> 0x89, 0x61, 0x85, 0xc3, 0x2d, 0xd3 }}
> gEfiFirmwareFileSystem3Guid      = { 0x5473c07a, 0x3dcb, 0x4dca, { 0xbd, 0x6f,
> 0x1e, 0x96, 0x89, 0xe7, 0x34, 0x9a }}
> 
>   From the dump message, the root FV File System ID is 5473c07a-3dcb-4dca-
> bd6f-1e9689e7349a. It is FF3 file system.
> 
> Thanks
> Liming
> > -----Original Message-----
> > From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of
> > Sean Brogan
> > Sent: Thursday, October 20, 2016 7:09 AM
> > To: edk2-devel@lists.01.org
> > Subject: [edk2] question about a compressed Ffs3 file inside FFS2
> > filesystem
> >
> > We have a condition that occurs when we boot where we see the
> > following message and our boot fails because of it.
> > DEBUG ((EFI_D_ERROR, "Found a FFS3 formatted section in a non-FFS3
> > formatted FV.\n"));
> >
> > Which is on line 773 of FwVol.c
> > ( https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Core/Pe
> > i/FwVol/FwVol.c )
> >
> > The condition is caused by a large firmware volume (greater than 16mb)
> > that is compressed and put into a smaller FV (less than 16mb).  My
> > question is why isn't this allowed (seems like a valid scenario).
> > Volinfo supports this and decodes binary fine.  The PI Vol 3 spec has
> > a section 3.2.2 EFI_FIRMWARE_FILE_SYSTEM3_GUID which says FileSystem2
> > doesn't support large files but it seems that the code is not taking
> > into account that the section is compressed and therefore you can have
> > a large file inside a compressed section inside a FV with File System2.
> >
> > Feedback/thoughts/comments/Bug?
> >
> > Here are some details of my scenario.
> > Compressed FV has filesystem == 8c8ce578-8a3d-4f1c-9935-896185c32dd3
> > (ffs3)
> > Non compressed FV has filesystem == 5473c07a-3dcb-4dca-bd6f-
> > 1e9689e7349a (ffs2)
> >
> > VolInfo dump of the Non Compressed FV showing the nested/compressed FV
> > inside.
> >
> > Decoding
> > VolInfo Version 1.0 Build Build 20909
> > Signature:        _FVH (4856465F)
> > Attributes:       4FEFF
> >        EFI_FVB2_READ_DISABLED_CAP
> >        EFI_FVB2_READ_ENABLED_CAP
> >        EFI_FVB2_READ_STATUS
> >        EFI_FVB2_WRITE_DISABLED_CAP
> >        EFI_FVB2_WRITE_ENABLED_CAP
> >        EFI_FVB2_WRITE_STATUS
> >        EFI_FVB2_LOCK_CAP
> >        EFI_FVB2_LOCK_STATUS
> >        EFI_FVB2_STICKY_WRITE
> >        EFI_FVB2_MEMORY_MAPPED
> >        EFI_FVB2_ERASE_POLARITY
> >        EFI_FVB2_READ_LOCK_CAP
> >        EFI_FVB2_READ_LOCK_STATUS
> >        EFI_FVB2_WRITE_LOCK_CAP
> >        EFI_FVB2_WRITE_LOCK_STATUS
> >         EFI_FVB2_ALIGNMENT_16
> >         EFI_FVB2_ALIGNMENT_32
> >         EFI_FVB2_ALIGNMENT_64
> >         EFI_FVB2_ALIGNMENT_128
> >         EFI_FVB2_ALIGNMENT_4K
> >         EFI_FVB2_ALIGNMENT_8K
> >         EFI_FVB2_ALIGNMENT_16K
> >         EFI_FVB2_ALIGNMENT_32K
> >         EFI_FVB2_ALIGNMENT_1M
> >         EFI_FVB2_ALIGNMENT_2M
> >        EFI_FVB2_ALIGNMENT_4M
> >         EFI_FVB2_ALIGNMENT_8M
> >         EFI_FVB2_ALIGNMENT_256M
> >         EFI_FVB2_ALIGNMENT_512M
> >         EFI_FVB2_ALIGNMENT_1G
> >         EFI_FVB2_ALIGNMENT_2G
> > Header Length:         0x00000048
> > File System ID:        5473c07a-3dcb-4dca-bd6f-1e9689e7349a
> > Revision:              0x0002
> > Number of Blocks:      0x00000028
> > Block Length:          0x00010000
> > Total Volume Size:     0x00280000
> > ==========================================================
> > ==
> > File Name:        9E21FD93-9C72-4C15-8C4B-E77F1DB2D792
> > File Offset:      0x00000048
> > File Length:      0x001F3FFD
> > File Attributes:  0x00
> > File State:       0xF8
> >         EFI_FILE_DATA_VALID
> > File Type:        0x0B  EFI_FV_FILETYPE_FIRMWARE_VOLUME_IMAGE
> > ------------------------------------------------------------
> >   Type:  EFI_SECTION_GUID_DEFINED
> >   Size:  0x001F3FE5
> >   SectionDefinitionGuid:  ee4e5898-3914-4259-9d6e-dc7bd79403cf
> >
> >   DataOffset:             0x0018
> >   Attributes:             0x0001
> > ------------------------------------------------------------
> >   Type:  EFI_SECTION_RAW
> >   Size:  0x00000FF8
> > ------------------------------------------------------------
> >   Type:  EFI_SECTION_FIRMWARE_VOLUME_IMAGE
> >   Size:  0x01010008
> > ==========================================================
> > ==
> >
> > Thanks
> > Sean
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