On 06/22/16 20:53, Achin Gupta wrote: > Hi All, > > I having some trouble trying an experiment on the AARCH64 Base FVP with UEFI > and > ARM Trusted Firmware. There is a buffer that is allocated by the latter in > DRAM > with TZC-400 attributes that allow non-secure access. Its extents are made > available to a UEFI DXE driver through an SMC. AFAIU, it should be added to > the > UEFI memory map/EL2 translation tables and subsequently allocated before it > can > be used. > > To add it to the memory map, I successfully call AddMemorySpace() GCD service > as > follows: > > Status = gDS->AddMemorySpace(EfiGcdMemoryTypeSystemMemory, > (EFI_PHYSICAL_ADDRESS) mNsBufferAddress, > mNsBufferMaxSize, > EFI_MEMORY_WB | EFI_MEMORY_XP); > > To allocate this buffer, I call AllocateMemorySpace GCD service immediately > after AddMemorySpace() as follows: > > Status = gDS->AllocateMemorySpace(EfiGcdAllocateAddress, > EfiGcdMemoryTypeSystemMemory, > EFI_PAGE_SHIFT, > mNsBufferMaxSize, > (EFI_PHYSICAL_ADDRESS *) &mNsBufferAddress, > ImageHandle, > NULL); > > The address of the buffer is 0xfbe00000 and size is 0x200000 i.e. it is > aligned > to the page boundary. This call fails with EFI_NOT_FOUND. I am unable to > figure > out what is going wrong. Am I using these interfaces in their intended way?
I recall the following from the relevant volume of the PI spec (please look it up and double check it): when you add memory space of type EfiGcdMemoryTypeSystemMemory, it is immediately absorbed by the pool / page UEFI memory allocation services, for their internal management. So after you add this, you can't allocate memory *space* of EfiGcdMemoryTypeSystemMemory. If you want to allocate system memory, just use the AllocatePool() / AllocatePages() boot services. The pattern that you use above is valid, but you should use a different GCD memory type (probably EfiGcdMemoryTypeReserved). If you definitely need "system memory" (= plain memory) to reside at this address, and want to allocate it right after adding it to the global coherency domain as EfiGcdMemoryTypeSystemMemory, then allocate it with the AllocatePages() boot service, setting the first argument (--> EFI_ALLOCATE_TYPE) to AllocateAddress (--> attempt to allocate at the fixed address). Just my two cents. Thanks Laszlo > > I have tried ignoring the error returned by AllocateMemorySpace(). This is > under > the assumption that AddMemorySpace() must have added it to the translation > tables. So the buffer must be accessible even though it is not yet marked as > allocated. However, I eventually run into translation faults with this > approach. > > Can anyone provide some insight? Please let me know if you need any > clarifications. > > Thanks a lot, > Achin > > _______________________________________________ > 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
