Re: [PATCH 4/4] OvmfPkg: Introduce UDF_ENABLE build flag

[Laszlo Ersek <lersek@redhat.com>]

On 08/09/17 17:45, Andrew Fish wrote:
> 
>> On Aug 9, 2017, at 2:44 AM, Laszlo Ersek <lersek@redhat.com> wrote:
>>
>> CC Ard and Andrew
>>
>> On 08/08/17 21:31, Paulo Alcantara wrote:
>>> By defining this build flag, OVMF will support booting from UDF file
>>> systems.
>>>
>>> Cc: Jordan Justen <jordan.l.justen@intel.com>
>>> Cc: Laszlo Ersek <lersek@redhat.com>
>>> Contributed-under: TianoCore Contribution Agreement 1.1
>>> Signed-off-by: Paulo Alcantara <pcacjr@zytor.com>
>>> ---
>>> OvmfPkg/OvmfPkgIa32.dsc    | 7 +++++++
>>> OvmfPkg/OvmfPkgIa32.fdf    | 3 +++
>>> OvmfPkg/OvmfPkgIa32X64.dsc | 7 +++++++
>>> OvmfPkg/OvmfPkgIa32X64.fdf | 3 +++
>>> OvmfPkg/OvmfPkgX64.dsc     | 7 +++++++
>>> OvmfPkg/OvmfPkgX64.fdf     | 3 +++
>>> 6 files changed, 30 insertions(+)
>>
>> Ray already mentioned that PcdUdfFileSystemSupport is not needed. I
>> agree. Similarly, I think UDF_ENABLE is also not needed, the new driver
>> should be added to the DSC and FDF files right after "Fat.inf" (like you
>> are doing it now, just unconditionally).
>>
>> Furthermore, can you please do the same in the ArmVirtPkg DSC and FDF
>> files? (Just grep the tree for "Fat.inf".) EmulatorPkg and Nt32Pkg are
>> further emulation platforms that might want to include this.
>>
>> My reason for suggesting the unconditional inclusion is the following
>> sentence from the UEFI 2.7 spec:
>>
>>  13 Protocols — Media Access
>>  13.3 File System Format
>>  13.3.2 Partition Discovery
>>  13.3.2.1 ISO-9660 and El Torito
>>
>>  [...] DVD-ROM images formatted as required by the UDF 2.0
>>  specification (OSTA Universal Disk Format Specification, Revision 2.0)
>>  can be booted by EFI. [...]
>>
>> It does not say "may be bootable", it says "can be booted".
>>
>> It would be interesting to see the Mantis ticket (if any) that got this
>> language into the spec, without the edk2 reference implementation
>> providing a UDF driver.
>> - Using the Mantis simple search function, "UDF" brings up nothing.
>> - From some googling, this sentence appears to go back to EFI 1.10 at
>>  the least.
>>
>> Andrew, do you remember the history of the quoted sentence?
>>
> 
> UDF defines a "UDF Bridge" disk that is "El Torito" compatible. So UDF punted on boot ability by allowing compatibility with CD-ROMs. 
> 
>  EFI supports booting from an ISO-9660 file system that conforms to the “El Torito” Bootable CD-ROM Format Specification on a DVD- ROM. A DVD-ROM that contains an ISO-9660 file system is defined as a “UDF Bridge” disk. Booting from CD-ROM and DVD-ROM is accomplished using the same methods.
> 
> I'm fine with adding a UDF file system driver, but it is not required from a UEFI Spec conformance point of view.

But the one sentence that I quoted above (from the spec) gives rise to
this exact impression:

  [...] DVD-ROM images formatted as required by the UDF 2.0
  specification (OSTA Universal Disk Format Specification, Revision 2.0)
  can be booted by EFI. [...]

Yes, it goes on to talk about "UDF Bridge", but this sentence per se
seems to require booting UDF optical media. The next sentence ("EFI
supports booting from an ISO-9660 file system...") does not start with
"Namely,".

So is this a spec bug?

I'd like to clarify this, because the intent of the above phrase
determines whether:
- edk2, as-is, conforms or does not conform to that passage of the spec,
- optical media that is formatted with UDF (and no ISO9660/ElTorito
  compat) qualifies as EFI-compatible (that edk2 currently cannot boot).

Could you recommend improved wording for the spec? I'd be happy to file
a Mantis item on your behalf.

Thanks,
Laszlo

> 
> Thanks,
> 
> Andrew Fish
> 
> PS "El Torito" was the restaurant that Curtis and Stan wrote out the proposal on a napkin. Luckily device paths are not called "House of Teriyaki", or even worse the nickname "rats and rice".  
> 
>> Paulo, I'll check if I can test your driver with some 3rd party media
>> (i.e., a DVD image that I don't prepare myself).
>>
>> Thank you!
>> Laszlo
>>
>>>
>>> diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
>>> index 5a14325f73..c71c332efd 100644
>>> --- a/OvmfPkg/OvmfPkgIa32.dsc
>>> +++ b/OvmfPkg/OvmfPkgIa32.dsc
>>> @@ -39,6 +39,7 @@
>>>   DEFINE HTTP_BOOT_ENABLE        = FALSE
>>>   DEFINE SMM_REQUIRE             = FALSE
>>>   DEFINE TLS_ENABLE              = FALSE
>>> +  DEFINE UDF_ENABLE              = FALSE
>>>
>>>   #
>>>   # Flash size selection. Setting FD_SIZE_IN_KB on the command line directly to
>>> @@ -409,6 +410,9 @@
>>>   gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire|TRUE
>>>   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection|FALSE
>>> !endif
>>> +!if $(UDF_ENABLE) == TRUE
>>> +  gEfiMdeModulePkgTokenSpaceGuid.PcdUdfFileSystemSupport|TRUE
>>> +!endif
>>>
>>> [PcdsFixedAtBuild]
>>>   gEfiMdeModulePkgTokenSpaceGuid.PcdStatusCodeMemorySize|1
>>> @@ -685,6 +689,9 @@
>>>   MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDxe.inf
>>>   MdeModulePkg/Universal/Disk/UnicodeCollation/EnglishDxe/EnglishDxe.inf
>>>   FatPkg/EnhancedFatDxe/Fat.inf
>>> +!if $(UDF_ENABLE) == TRUE
>>> +  MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
>>> +!endif
>>>   MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBusDxe.inf
>>>   MdeModulePkg/Bus/Scsi/ScsiDiskDxe/ScsiDiskDxe.inf
>>>   OvmfPkg/SataControllerDxe/SataControllerDxe.inf
>>> diff --git a/OvmfPkg/OvmfPkgIa32.fdf b/OvmfPkg/OvmfPkgIa32.fdf
>>> index 5e5ade2a1f..2da1fcbe1f 100644
>>> --- a/OvmfPkg/OvmfPkgIa32.fdf
>>> +++ b/OvmfPkg/OvmfPkgIa32.fdf
>>> @@ -282,6 +282,9 @@ INF  MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/BootScriptExecutorDxe.inf
>>> INF  MdeModulePkg/Universal/Acpi/BootGraphicsResourceTableDxe/BootGraphicsResourceTableDxe.inf
>>>
>>> INF  FatPkg/EnhancedFatDxe/Fat.inf
>>> +!if $(UDF_ENABLE) == TRUE
>>> +INF  MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
>>> +!endif
>>>
>>> !ifndef $(USE_OLD_SHELL)
>>> INF  ShellPkg/Application/Shell/Shell.inf
>>> diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
>>> index 2f17a70db8..d0785cca13 100644
>>> --- a/OvmfPkg/OvmfPkgIa32X64.dsc
>>> +++ b/OvmfPkg/OvmfPkgIa32X64.dsc
>>> @@ -39,6 +39,7 @@
>>>   DEFINE HTTP_BOOT_ENABLE        = FALSE
>>>   DEFINE SMM_REQUIRE             = FALSE
>>>   DEFINE TLS_ENABLE              = FALSE
>>> +  DEFINE UDF_ENABLE              = FALSE
>>>
>>>   #
>>>   # Flash size selection. Setting FD_SIZE_IN_KB on the command line directly to
>>> @@ -414,6 +415,9 @@
>>>   gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire|TRUE
>>>   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection|FALSE
>>> !endif
>>> +!if $(UDF_ENABLE) == TRUE
>>> +  gEfiMdeModulePkgTokenSpaceGuid.PcdUdfFileSystemSupport|TRUE
>>> +!endif
>>>
>>> [PcdsFixedAtBuild]
>>>   gEfiMdeModulePkgTokenSpaceGuid.PcdStatusCodeMemorySize|1
>>> @@ -694,6 +698,9 @@
>>>   MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDxe.inf
>>>   MdeModulePkg/Universal/Disk/UnicodeCollation/EnglishDxe/EnglishDxe.inf
>>>   FatPkg/EnhancedFatDxe/Fat.inf
>>> +!if $(UDF_ENABLE) == TRUE
>>> +  MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
>>> +!endif
>>>   MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBusDxe.inf
>>>   MdeModulePkg/Bus/Scsi/ScsiDiskDxe/ScsiDiskDxe.inf
>>>   OvmfPkg/SataControllerDxe/SataControllerDxe.inf
>>> diff --git a/OvmfPkg/OvmfPkgIa32X64.fdf b/OvmfPkg/OvmfPkgIa32X64.fdf
>>> index aa0d8c69f3..0fdd359051 100644
>>> --- a/OvmfPkg/OvmfPkgIa32X64.fdf
>>> +++ b/OvmfPkg/OvmfPkgIa32X64.fdf
>>> @@ -283,6 +283,9 @@ INF  MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/BootScriptExecutorDxe.inf
>>> INF  MdeModulePkg/Universal/Acpi/BootGraphicsResourceTableDxe/BootGraphicsResourceTableDxe.inf
>>>
>>> INF  FatPkg/EnhancedFatDxe/Fat.inf
>>> +!if $(UDF_ENABLE) == TRUE
>>> +INF  MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
>>> +!endif
>>>
>>> !ifndef $(USE_OLD_SHELL)
>>> INF  ShellPkg/Application/Shell/Shell.inf
>>> diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
>>> index c0bd5d0ea6..a25d8b1e99 100644
>>> --- a/OvmfPkg/OvmfPkgX64.dsc
>>> +++ b/OvmfPkg/OvmfPkgX64.dsc
>>> @@ -39,6 +39,7 @@
>>>   DEFINE HTTP_BOOT_ENABLE        = FALSE
>>>   DEFINE SMM_REQUIRE             = FALSE
>>>   DEFINE TLS_ENABLE              = FALSE
>>> +  DEFINE UDF_ENABLE              = FALSE
>>>
>>>   #
>>>   # Flash size selection. Setting FD_SIZE_IN_KB on the command line directly to
>>> @@ -414,6 +415,9 @@
>>>   gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire|TRUE
>>>   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection|FALSE
>>> !endif
>>> +!if $(UDF_ENABLE) == TRUE
>>> +  gEfiMdeModulePkgTokenSpaceGuid.PcdUdfFileSystemSupport|TRUE
>>> +!endif
>>>
>>> [PcdsFixedAtBuild]
>>>   gEfiMdeModulePkgTokenSpaceGuid.PcdStatusCodeMemorySize|1
>>> @@ -692,6 +696,9 @@
>>>   MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDxe.inf
>>>   MdeModulePkg/Universal/Disk/UnicodeCollation/EnglishDxe/EnglishDxe.inf
>>>   FatPkg/EnhancedFatDxe/Fat.inf
>>> +!if $(UDF_ENABLE) == TRUE
>>> +  MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
>>> +!endif
>>>   MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBusDxe.inf
>>>   MdeModulePkg/Bus/Scsi/ScsiDiskDxe/ScsiDiskDxe.inf
>>>   OvmfPkg/SataControllerDxe/SataControllerDxe.inf
>>> diff --git a/OvmfPkg/OvmfPkgX64.fdf b/OvmfPkg/OvmfPkgX64.fdf
>>> index 98a0cf17da..8ae591c1f5 100644
>>> --- a/OvmfPkg/OvmfPkgX64.fdf
>>> +++ b/OvmfPkg/OvmfPkgX64.fdf
>>> @@ -283,6 +283,9 @@ INF  MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/BootScriptExecutorDxe.inf
>>> INF  MdeModulePkg/Universal/Acpi/BootGraphicsResourceTableDxe/BootGraphicsResourceTableDxe.inf
>>>
>>> INF  FatPkg/EnhancedFatDxe/Fat.inf
>>> +!if $(UDF_ENABLE) == TRUE
>>> +INF  MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
>>> +!endif
>>>
>>> !ifndef $(USE_OLD_SHELL)
>>> INF  ShellPkg/Application/Shell/Shell.inf
>>>
>>
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> 
>