On Thu, 18 Oct 2018 at 14:54, Leif Lindholm <[email protected]> wrote:
>
> On Thu, Oct 18, 2018 at 02:43:37PM +0530, Sumit Garg wrote:
> > On Thu, 18 Oct 2018 at 14:04, Leif Lindholm <[email protected]>
> > wrote:
> > >
> > > On Thu, Oct 18, 2018 at 12:59:32PM +0530, Sumit Garg wrote:
> > > > > So, looking at the OpTee sources, TEE_UUID is defined as a struct, to
> > > > > exactly the same layout as the EFI_GUID type (which is a typedef of
> > > > > the GUID struct). Could we add a OPTEE_UUID typedef for the same
> > > > > struct in OpteeLib.h?
> > > > >
> > > > > Since it comes in as an OPTEE_MESSAGE_PARAM_VALUE, alignment is
> > > > > already guaranteed to be 64-bit.
> > > > >
> > > > > (This also deserves a comment explaining how EFI_GUID basically
> > > > > follows rfc4122, but uses little-endian for the timestamp fields.)
> > > >
> > > > Actually, OP-TEE also uses little-endian format for timestamp fields.
> > > > You can refer to [1] for conversion from network byte order (octets)
> > > > to little-endian and vice-versa.
> > > >
> > > > So for communications among secure world and non-secure world it uses
> > > > network byte order for UUID/GUID to comply with rfc4122.
> > > >
> > > > [1] https://github.com/OP-TEE/optee_os/blob/master/core/tee/uuid.c
> > >
> > > Huh, ok. That's good to know.
> > > It does however not change my comments. Since we're dealing with data
> > > structures of a known layout, I am not a fan of treating them as byte
> > > arrays.
> > >
> >
> > But calling UUID struct with swapped timestamp as OPTEE_UUID would
> > also be misnomer. I am not sure regarding appropriate naming for that
> > struct.
>
> That's a fair point. We could call it RFC4122_UUID for now.
>
Ok then in v5 I will define this as internal communication structure
in ArmPkg/Library/OpteeLib/OpteeSmc.h and use it instead in following
manner. Please review it.
diff --git a/ArmPkg/Library/OpteeLib/OpteeSmc.h
b/ArmPkg/Library/OpteeLib/OpteeSmc.h
index 21ff4b22ab92..9cccd81810c9 100644
--- a/ArmPkg/Library/OpteeLib/OpteeSmc.h
+++ b/ArmPkg/Library/OpteeLib/OpteeSmc.h
@@ -40,4 +40,14 @@ typedef struct {
UINTN Size;
} OPTEE_SHARED_MEMORY_INFORMATION;
+//
+// UUID struct compliant with RFC4122 (network byte order).
+//
+typedef struct {
+ UINT32 Data1;
+ UINT16 Data2;
+ UINT16 Data3;
+ UINT8 Data4[8];
+} RFC4122_UUID;
+
#endif
diff --git a/ArmPkg/Library/OpteeLib/Optee.c b/ArmPkg/Library/OpteeLib/Optee.c
index 6617126e8bdb..8ac31cb28266 100644
--- a/ArmPkg/Library/OpteeLib/Optee.c
+++ b/ArmPkg/Library/OpteeLib/Optee.c
@@ -165,20 +165,15 @@ OpteeCallWithArg (
STATIC
VOID
-UuidToOctets (
- OUT UINT8 *UuidOctet,
- IN EFI_GUID *Uuid
+EfiGuidToRfc4122Uuid (
+ OUT RFC4122_UUID *Rfc4122Uuid,
+ IN EFI_GUID *Guid
)
{
- UuidOctet[0] = Uuid->Data1 >> 24;
- UuidOctet[1] = Uuid->Data1 >> 16;
- UuidOctet[2] = Uuid->Data1 >> 8;
- UuidOctet[3] = Uuid->Data1;
- UuidOctet[4] = Uuid->Data2 >> 8;
- UuidOctet[5] = Uuid->Data2;
- UuidOctet[6] = Uuid->Data3 >> 8;
- UuidOctet[7] = Uuid->Data3;
- CopyMem (UuidOctet + 8, Uuid->Data4, sizeof (Uuid->Data4));
+ Rfc4122Uuid->Data1 = SwapBytes32 (Guid->Data1);
+ Rfc4122Uuid->Data2 = SwapBytes16 (Guid->Data2);
+ Rfc4122Uuid->Data3 = SwapBytes16 (Guid->Data3);
+ CopyMem (Rfc4122Uuid->Data4, Guid->Data4, sizeof (Rfc4122Uuid->Data4));
}
EFI_STATUS
@@ -209,8 +204,8 @@ OpteeOpenSession (
OPTEE_MESSAGE_ATTRIBUTE_META;
MessageArg->Params[1].Attribute = OPTEE_MESSAGE_ATTRIBUTE_TYPE_VALUE_INPUT |
OPTEE_MESSAGE_ATTRIBUTE_META;
- UuidToOctets (
- (UINT8 *)&MessageArg->Params[0].Union.Value,
+ EfiGuidToRfc4122Uuid (
+ (RFC4122_UUID *)&MessageArg->Params[0].Union.Value,
&OpenSessionArg->Uuid
);
ZeroMem (&MessageArg->Params[1].Union.Value, sizeof (EFI_GUID));
-Sumit
> There could even be a case to add that to BaseLib at some point (but
> probably not while there is only one user).
>
> Regards,
>
> Leif
>
> > On the other hand, we have byte array of 16 octets as per network byte
> > order complying with rfc4122 which also doesn't imply swapped
> > timestamp.
> >
> > -Sumit
> >
> > > /
> > > Leif
_______________________________________________
edk2-devel mailing list
[email protected]
https://lists.01.org/mailman/listinfo/edk2-devel
