diff options
Diffstat (limited to 'OvmfPkg/Fdt/HighMemDxe/HighMemDxe.c')
| -rw-r--r-- | OvmfPkg/Fdt/HighMemDxe/HighMemDxe.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/OvmfPkg/Fdt/HighMemDxe/HighMemDxe.c b/OvmfPkg/Fdt/HighMemDxe/HighMemDxe.c new file mode 100644 index 0000000000..c383757364 --- /dev/null +++ b/OvmfPkg/Fdt/HighMemDxe/HighMemDxe.c @@ -0,0 +1,128 @@ +/** @file
+* High memory node enumeration DXE driver for ARM Virtual Machines
+*
+* Copyright (c) 2015-2016, Linaro Ltd. All rights reserved.
+*
+* SPDX-License-Identifier: BSD-2-Clause-Patent
+*
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/DxeServicesTableLib.h>
+#include <Library/PcdLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+
+#include <Protocol/Cpu.h>
+#include <Protocol/FdtClient.h>
+
+EFI_STATUS
+EFIAPI
+InitializeHighMemDxe (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ FDT_CLIENT_PROTOCOL *FdtClient;
+ EFI_CPU_ARCH_PROTOCOL *Cpu;
+ EFI_STATUS Status, FindNodeStatus;
+ INT32 Node;
+ CONST UINT32 *Reg;
+ UINT32 RegSize;
+ UINTN AddressCells, SizeCells;
+ UINT64 CurBase;
+ UINT64 CurSize;
+ UINT64 Attributes;
+ EFI_GCD_MEMORY_SPACE_DESCRIPTOR GcdDescriptor;
+
+ Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
+ (VOID **)&FdtClient);
+ ASSERT_EFI_ERROR (Status);
+
+ Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL,
+ (VOID **)&Cpu);
+ ASSERT_EFI_ERROR (Status);
+
+ //
+ // Check for memory node and add the memory spaces except the lowest one
+ //
+ for (FindNodeStatus = FdtClient->FindMemoryNodeReg (FdtClient, &Node,
+ (CONST VOID **) &Reg, &AddressCells,
+ &SizeCells, &RegSize);
+ !EFI_ERROR (FindNodeStatus);
+ FindNodeStatus = FdtClient->FindNextMemoryNodeReg (FdtClient, Node,
+ &Node, (CONST VOID **) &Reg, &AddressCells,
+ &SizeCells, &RegSize)) {
+ ASSERT (AddressCells <= 2);
+ ASSERT (SizeCells <= 2);
+
+ while (RegSize > 0) {
+ CurBase = SwapBytes32 (*Reg++);
+ if (AddressCells > 1) {
+ CurBase = (CurBase << 32) | SwapBytes32 (*Reg++);
+ }
+ CurSize = SwapBytes32 (*Reg++);
+ if (SizeCells > 1) {
+ CurSize = (CurSize << 32) | SwapBytes32 (*Reg++);
+ }
+ RegSize -= (AddressCells + SizeCells) * sizeof (UINT32);
+
+ Status = gDS->GetMemorySpaceDescriptor (CurBase, &GcdDescriptor);
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_WARN,
+ "%a: Region 0x%lx - 0x%lx not found in the GCD memory space map\n",
+ __FUNCTION__, CurBase, CurBase + CurSize - 1));
+ continue;
+ }
+ if (GcdDescriptor.GcdMemoryType == EfiGcdMemoryTypeNonExistent) {
+ Status = gDS->AddMemorySpace (EfiGcdMemoryTypeSystemMemory, CurBase,
+ CurSize, EFI_MEMORY_WB);
+
+ if (EFI_ERROR (Status)) {
+ DEBUG ((EFI_D_ERROR,
+ "%a: Failed to add System RAM @ 0x%lx - 0x%lx (%r)\n",
+ __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
+ continue;
+ }
+
+ Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize,
+ EFI_MEMORY_WB);
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_WARN,
+ "%a: gDS->SetMemorySpaceAttributes() failed on region 0x%lx - 0x%lx (%r)\n",
+ __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
+ }
+
+ //
+ // Due to the ambiguous nature of the RO/XP GCD memory space attributes,
+ // it is impossible to add a memory space with the XP attribute in a way
+ // that does not result in the XP attribute being set on *all* UEFI
+ // memory map entries that are carved from it, including code regions
+ // that require executable permissions.
+ //
+ // So instead, we never set the RO/XP attributes in the GCD memory space
+ // capabilities or attribute fields, and apply any protections directly
+ // on the page table mappings by going through the cpu arch protocol.
+ //
+ Attributes = EFI_MEMORY_WB;
+ if ((PcdGet64 (PcdDxeNxMemoryProtectionPolicy) &
+ (1U << (UINT32)EfiConventionalMemory)) != 0) {
+ Attributes |= EFI_MEMORY_XP;
+ }
+
+ Status = Cpu->SetMemoryAttributes (Cpu, CurBase, CurSize, Attributes);
+
+ if (EFI_ERROR (Status)) {
+ DEBUG ((EFI_D_ERROR,
+ "%a: Failed to set System RAM @ 0x%lx - 0x%lx attribute (%r)\n",
+ __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
+ } else {
+ DEBUG ((EFI_D_INFO, "%a: Add System RAM @ 0x%lx - 0x%lx\n",
+ __FUNCTION__, CurBase, CurBase + CurSize - 1));
+ }
+ }
+ }
+ }
+
+ return EFI_SUCCESS;
+}
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