Eugene, I am confused by one aspect of this proposal.
The GUID values for PPIs, DXE Protocols, UEFI Protocols, and SMM Protocols are unique. Which means if code is written to work in one phase, you can not share code to another phase because the GUID values must be changed. The other libs you mentioned have the attribute that the parameters to the library APIs do not have to be updated as source code is moved or shared between phase types. Given that the source can not be shared, what is gained by adding a library? Would you recommend using this lib in all module types? Maybe you can share both the proposed library class APIs and typical usage from different module types. Mike > -----Original Message----- > From: edk2-devel [mailto:[email protected]] On Behalf Of Cohen, > Eugene > Sent: Monday, October 10, 2016 8:24 AM > To: Gao, Liming <[email protected]>; Laszlo Ersek <[email protected]>; > edk2- > [email protected] <[email protected]>; Kinney, Michael D > <[email protected]>; Yao, Jiewen <[email protected]>; Andrew Fish > ([email protected]) <[email protected]> > Subject: Re: [edk2] RFC: ProtocolLib for cross DXE and SMM Protocol and Handle > Services > > Liming, > > Could this library cover PEI PPI? > > Yes - excellent suggestion for PEI - I hadn't considered it because the use > case > hadn't come up for me yet. > > > And, I think this library class will include Install, Notify and Locate > > APIs. > Right? > > Yes, this library class proposal incorporates all of the protocol and handle > database > related functionality. Notify may be tricky since in DXE we have TPL and > both PEI > and SMM we have direct function callbacks but perhaps there's a way to > abstract if we > assume a default TPL or an alternate library API to initialize the callback > TPL in > advance. (On the other hand this could introduce subtle bugs if driver > developers > lose sight of the TPL used for callbacks on this interface.) > > Given the positive feedback the next step is to publish a proposed library > header > file for review. > > Thanks, > > Eugene > > From: Gao, Liming [mailto:[email protected]] > Sent: Saturday, October 08, 2016 7:50 PM > To: Cohen, Eugene <[email protected]>; Laszlo Ersek <[email protected]>; edk2- > [email protected] <[email protected]>; Kinney, Michael D > <[email protected]>; Yao, Jiewen <[email protected]>; Andrew Fish > ([email protected]) <[email protected]> > Subject: RE: [edk2] RFC: ProtocolLib for cross DXE and SMM Protocol and Handle > Services > > Eugene: > Could this library cover PEI PPI? LocatePpi and LocateProtocol both return > VOID**. > And, I think this library class will include Install, Notify and Locate APIs. > Right? > > typedef > EFI_STATUS > (EFIAPI *EFI_PEI_LOCATE_PPI)( > IN CONST EFI_PEI_SERVICES **PeiServices, > IN CONST EFI_GUID *Guid, > IN UINTN Instance, > IN OUT EFI_PEI_PPI_DESCRIPTOR **PpiDescriptor OPTIONAL, > IN OUT VOID **Ppi > ); > > typedef > EFI_STATUS > (EFIAPI *EFI_LOCATE_PROTOCOL)( > IN EFI_GUID *Protocol, > IN VOID *Registration, OPTIONAL > OUT VOID **Interface > ); > > Thanks > Liming > From: edk2-devel [mailto:[email protected]] On Behalf Of Cohen, > Eugene > Sent: Saturday, October 1, 2016 6:05 AM > To: Laszlo Ersek <[email protected]<mailto:[email protected]>>; edk2- > [email protected]<mailto:[email protected]> <edk2- > [email protected]<mailto:[email protected]>>; Kinney, Michael D > <[email protected]<mailto:[email protected]>>; Yao, Jiewen > <[email protected]<mailto:[email protected]>>; Andrew Fish > ([email protected]<mailto:[email protected]>) > <[email protected]<mailto:[email protected]>> > Subject: Re: [edk2] RFC: ProtocolLib for cross DXE and SMM Protocol and Handle > Services > > > I believe I understood this. However, in the entry point function of an > > SMM driver, it is permitted to look for, and invoke member functions > > of, > > both SMM and DXE protocols [1]. If the library instance that is > > supposed > > to be linked into SMM drivers is tied to the SMM protocol database > > solely, then it won't be able to serve the use case when an SMM driver > > looks for a DXE protocol in its entry point function. > > Agreed - non-standalone SMM drivers (notice the new terminology I'm injecting > to > prepare us for PI 1.5) can peek over at UEFI/DXE. This is not the use case > I'm trying > to enable here (and I would argue as an industry is a practice we will try to > discourage over time). > > > ... Actually, I believe this applies even to MemoryAllocationLib. In an > > SMM driver, the SMM-tailored MemoryAllocationLib instance only > > allocates > > SMRAM, which is mostly fine. However, it is unsuitable for allocating > > (for example) EfiBootServicesData type memory, even though that too > > is > > permitted in the SMM driver's entry point function, I think. For that, > > gBS->AllocatePool() or gBS->AllocatePages() have to be called > > explicitly. > > Right - so the common library abstraction allocates from the "native" memory > pool for > the driver type and if you want something else you have to go above and > beyond. So in > the spirit of that precedent I'd propose the same approach for a ProtocolLib > implementation. > > Thanks, great feedback. > > Eugene > _______________________________________________ > edk2-devel mailing list > [email protected]<mailto:[email protected]> > https://lists.01.org/mailman/listinfo/edk2-devel > _______________________________________________ > edk2-devel mailing list > [email protected] > https://lists.01.org/mailman/listinfo/edk2-devel _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
