1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
/** @file
* High memory node enumeration DXE driver for ARM Virtual Machines
*
* Copyright (c) 2015-2016, Linaro Ltd. All rights reserved.
*
* This program and the accompanying materials are licensed and made available
* under the terms and conditions of the BSD License which accompanies this
* distribution. The full text of the license may be found at
* http://opensource.org/licenses/bsd-license.php
*
* THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
* WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR
* IMPLIED.
*
**/
#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;
}
|
