diff --git a/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c b/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c index 303dc520c6..377262563e 100644 --- a/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c +++ b/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c @@ -14,12 +14,16 @@ WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. **/ +#include + #include #include #include #include -#include #include +#include + +#include STATIC UINTN mFwCfgSelectorAddress; STATIC UINTN mFwCfgDataAddress; @@ -115,8 +119,70 @@ QemuFwCfgInitialize ( VOID ) { - mFwCfgSelectorAddress = (UINTN)PcdGet64 (PcdFwCfgSelectorAddress); - mFwCfgDataAddress = (UINTN)PcdGet64 (PcdFwCfgDataAddress); + EFI_STATUS Status; + FDT_CLIENT_PROTOCOL *FdtClient; + CONST UINT64 *Reg; + UINT32 RegElemSize, RegSize; + UINT64 FwCfgSelectorAddress; + UINT64 FwCfgSelectorSize; + UINT64 FwCfgDataAddress; + UINT64 FwCfgDataSize; + UINT64 FwCfgDmaAddress; + UINT64 FwCfgDmaSize; + + Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL, + (VOID **)&FdtClient); + ASSERT_EFI_ERROR (Status); + + Status = FdtClient->FindCompatibleNodeReg (FdtClient, "qemu,fw-cfg-mmio", + (CONST VOID **)&Reg, &RegElemSize, &RegSize); + if (EFI_ERROR (Status)) { + DEBUG ((EFI_D_WARN, + "%a: No 'qemu,fw-cfg-mmio' compatible DT node found (Status == %r)\n", + __FUNCTION__, Status)); + return EFI_SUCCESS; + } + + ASSERT (RegElemSize == sizeof (UINT64)); + ASSERT (RegSize == 2 * sizeof (UINT64)); + + FwCfgDataAddress = SwapBytes64 (Reg[0]); + FwCfgDataSize = 8; + FwCfgSelectorAddress = FwCfgDataAddress + FwCfgDataSize; + FwCfgSelectorSize = 2; + + // + // The following ASSERT()s express + // + // Address + Size - 1 <= MAX_UINTN + // + // for both registers, that is, that the last byte in each MMIO range is + // expressible as a MAX_UINTN. The form below is mathematically + // equivalent, and it also prevents any unsigned overflow before the + // comparison. + // + ASSERT (FwCfgSelectorAddress <= MAX_UINTN - FwCfgSelectorSize + 1); + ASSERT (FwCfgDataAddress <= MAX_UINTN - FwCfgDataSize + 1); + + mFwCfgSelectorAddress = FwCfgSelectorAddress; + mFwCfgDataAddress = FwCfgDataAddress; + + DEBUG ((EFI_D_INFO, "Found FwCfg @ 0x%Lx/0x%Lx\n", FwCfgSelectorAddress, + FwCfgDataAddress)); + + if (SwapBytes64 (Reg[1]) >= 0x18) { + FwCfgDmaAddress = FwCfgDataAddress + 0x10; + FwCfgDmaSize = 0x08; + + // + // See explanation above. + // + ASSERT (FwCfgDmaAddress <= MAX_UINTN - FwCfgDmaSize + 1); + + DEBUG ((EFI_D_INFO, "Found FwCfg DMA @ 0x%Lx\n", FwCfgDmaAddress)); + } else { + FwCfgDmaAddress = 0; + } if (InternalQemuFwCfgIsAvailable ()) { UINT32 Signature; @@ -128,13 +194,13 @@ QemuFwCfgInitialize ( // For DMA support, we require the DTB to advertise the register, and the // feature bitmap (which we read without DMA) to confirm the feature. // - if (PcdGet64 (PcdFwCfgDmaAddress) != 0) { + if (FwCfgDmaAddress != 0) { UINT32 Features; QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion); Features = QemuFwCfgRead32 (); if ((Features & BIT1) != 0) { - mFwCfgDmaAddress = PcdGet64 (PcdFwCfgDmaAddress); + mFwCfgDmaAddress = FwCfgDmaAddress; InternalQemuFwCfgReadBytes = DmaReadBytes; } } diff --git a/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf b/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf index 298aa6edfb..eff4a21650 100644 --- a/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf +++ b/ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.inf @@ -46,9 +46,10 @@ BaseMemoryLib DebugLib IoLib - PcdLib + UefiBootServicesTableLib -[Pcd] - gArmVirtTokenSpaceGuid.PcdFwCfgSelectorAddress - gArmVirtTokenSpaceGuid.PcdFwCfgDataAddress - gArmVirtTokenSpaceGuid.PcdFwCfgDmaAddress +[Protocols] + gFdtClientProtocolGuid ## CONSUMES + +[Depex] + gFdtClientProtocolGuid