Re: StandaloneMmPkg comments

[Supreeth Venkatesh <supreeth.venkatesh@arm.com>]

On Sun, 2018-07-22 at 00:51 +0900, Ard Biesheuvel wrote:
> On 21 July 2018 at 03:57, Marvin H?user <Marvin.Haeuser@outlook.com>
> wrote:
> > 
> > Good day,
> > 
> > I have been reading through the recently imported StandaloneMmPkg
> > and found three odd things.
> > 
> > 
> >   1.  GUID prefixes: GUIDs defined in StandaloneMmPkg.dec either
> > have no common prefix at all ("gMmFv") or use the "gEfi" prefix.
> > Maybe the MdeModulePkg-style "gEdkii" prefix could be used for a
> > uniform style?
> The gEdkii prefix is used for GUIDs that are not defined in the PI or
> UEFI specs. The gEfi  prefix is used for GUIDs that are defined in
> either of those specs. I'm not sure what the rule is for prefixless
> GUIDs though.
> 
> > 
> >   2.  The "gEfiMmConfigurationProtocolGuid" name is common between
> > Standalone (StandaloneMmPkg.dec) and Traditional (MdePkg.dec) MM
> > context despite having a different value of course. Shouldn't the
> > naming reflect which is traditional and which is Standalone? I
> > haven't checked in depth, but which is chosen when a module
> > consumes both MdePkg and StandaloneMmPkg?
> That smells like a bug to me.
Sorry for the delayed response as I am catching up on emails after
vacation. 
I think that the naming should reflect which is traditional and which
is Standalone even when traditional and standalone are supposed to be
mutually exclusive.
MdePkg.dec has this define
gEfiMmConfigurationProtocolGuid= { 0x26eeb3de, 0xb689, 0x492e, { 0x80,
0xf0, 0xbe, 0x8b, 0xd7, 0xda, 0x4b, 0xa7 }} which is defined in PI Spec
v1.6 vol 4 in section 5.5. 


However, PI spec v1.6 vol 4 defines EFI_MM_CONFIGURATION_PROTOCOL_GUID
once more in section 4.8 (Standalone MM context) as
#define EFI_MM_CONFIGURATION_PROTOCOL_GUID { \
0xc109319, 0xc149, 0x450e, 0xa3, 0xe3, 0xb9, 0xba, 0xdd, 0x9d, 0xc3,
0xa4 \
}

Furthermore, it defines in Appendix A (Management Mode Backward
Compatibility Types):
#define EFI_SMM_CONFIGURATION_PROTOCOL_GUID
EFI_MM_CONFIGURATION_PROTOCOL_GUID.

It seems like an issue with the Specification. I have raised an ECR to
get some clarification.
https://mantis.uefi.org/mantis/view.php?id=1940

 
> 
> > 
> >   3.  While .dec already uses the "Mmram" naming scheme, its header
> > declares the MemoryReserve GUID as
> > "gEfiMmPeiS(!)mramMemoryReserveGuid". Furthermore, the header
> > references the SMM CIS (which has been replaced with "MM CIS" as
> > part of the renaming), while the GUID has changed and the structure
> > does not match the deprecated specification anyway. May I suggest
> > to turn this GUID into a "gEdkii"-style GUID and remove all
> > references to the SMM CIS? Maybe use the "EDKII_" prefix for
> > "EFI_MMRAM_HOB_DESCRIPTOR_BLOCK" too? I wanted to prepare a patch,
> > but I cannot compile the package at the moment and don't want to
> > risk submitting anything broken.
> > 
> As mentioned above, EDKII prefixes are inappropriate here, since
> standalone MM is defined in the PI spec. I will let others comment on
> the SMM CIS thing.