1 /** @file
2 Set a IDT entry for debug purpose
3
4 Set a IDT entry for interrupt vector 3 for debug purpose for x64 platform
5
6 Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
7
8 This program and the accompanying materials
9 are licensed and made available under the terms and conditions of the BSD License
10 which accompanies this distribution. The full text of the license may be found at
11 http://opensource.org/licenses/bsd-license.php
12
13 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
14 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
15
16 **/
17 #include "ScriptExecute.h"
18
19 //
20 // 8 extra pages for PF handler.
21 //
22 #define EXTRA_PAGE_TABLE_PAGES 8
23
24 #define IA32_PG_P BIT0
25 #define IA32_PG_RW BIT1
26 #define IA32_PG_PS BIT7
27
28 UINT64 mPhyMask;
29 VOID *mOriginalHandler;
30 UINTN mPageFaultBuffer;
31 UINTN mPageFaultIndex = 0;
32 //
33 // Store the uplink information for each page being used.
34 //
35 UINT64 *mPageFaultUplink[EXTRA_PAGE_TABLE_PAGES];
36
37 /**
38 Page fault handler.
39
40 **/
41 VOID
42 EFIAPI
43 PageFaultHandlerHook (
44 VOID
45 );
46
47 /**
48 Hook IDT with our page fault handler so that the on-demand paging works on page fault.
49
50 @param IdtEntry a pointer to IDT entry
51
52 **/
53 VOID
HookPageFaultHandler(IN IA32_IDT_GATE_DESCRIPTOR * IdtEntry)54 HookPageFaultHandler (
55 IN IA32_IDT_GATE_DESCRIPTOR *IdtEntry
56 )
57 {
58 UINT32 RegEax;
59 UINT8 PhysicalAddressBits;
60 UINTN PageFaultHandlerHookAddress;
61
62 AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);
63 if (RegEax >= 0x80000008) {
64 AsmCpuid (0x80000008, &RegEax, NULL, NULL, NULL);
65 PhysicalAddressBits = (UINT8) RegEax;
66 } else {
67 PhysicalAddressBits = 36;
68 }
69 mPhyMask = LShiftU64 (1, PhysicalAddressBits) - 1;
70 mPhyMask &= (1ull << 48) - SIZE_4KB;
71
72 //
73 // Set Page Fault entry to catch >4G access
74 //
75 PageFaultHandlerHookAddress = (UINTN)PageFaultHandlerHook;
76 mOriginalHandler = (VOID *)(UINTN)(LShiftU64 (IdtEntry->Bits.OffsetUpper, 32) + IdtEntry->Bits.OffsetLow + (IdtEntry->Bits.OffsetHigh << 16));
77 IdtEntry->Bits.OffsetLow = (UINT16)PageFaultHandlerHookAddress;
78 IdtEntry->Bits.Selector = (UINT16)AsmReadCs ();
79 IdtEntry->Bits.Reserved_0 = 0;
80 IdtEntry->Bits.GateType = IA32_IDT_GATE_TYPE_INTERRUPT_32;
81 IdtEntry->Bits.OffsetHigh = (UINT16)(PageFaultHandlerHookAddress >> 16);
82 IdtEntry->Bits.OffsetUpper = (UINT32)(PageFaultHandlerHookAddress >> 32);
83 IdtEntry->Bits.Reserved_1 = 0;
84
85 if (mPage1GSupport) {
86 mPageFaultBuffer = (UINTN)(AsmReadCr3 () & mPhyMask) + EFI_PAGES_TO_SIZE(2);
87 }else {
88 mPageFaultBuffer = (UINTN)(AsmReadCr3 () & mPhyMask) + EFI_PAGES_TO_SIZE(6);
89 }
90 ZeroMem (mPageFaultUplink, sizeof (mPageFaultUplink));
91 }
92
93 /**
94 The function will check if current waking vector is long mode.
95
96 @param AcpiS3Context a pointer to a structure of ACPI_S3_CONTEXT
97
98 @retval TRUE Current context need long mode waking vector.
99 @retval FALSE Current context need not long mode waking vector.
100 **/
101 BOOLEAN
IsLongModeWakingVector(IN ACPI_S3_CONTEXT * AcpiS3Context)102 IsLongModeWakingVector (
103 IN ACPI_S3_CONTEXT *AcpiS3Context
104 )
105 {
106 EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *Facs;
107
108 Facs = (EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *) ((UINTN) (AcpiS3Context->AcpiFacsTable));
109 if ((Facs == NULL) ||
110 (Facs->Signature != EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE) ||
111 ((Facs->FirmwareWakingVector == 0) && (Facs->XFirmwareWakingVector == 0)) ) {
112 // Something wrong with FACS
113 return FALSE;
114 }
115 if (Facs->XFirmwareWakingVector != 0) {
116 if ((Facs->Version == EFI_ACPI_4_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_VERSION) &&
117 ((Facs->Flags & EFI_ACPI_4_0_64BIT_WAKE_SUPPORTED_F) != 0) &&
118 ((Facs->Flags & EFI_ACPI_4_0_OSPM_64BIT_WAKE__F) != 0)) {
119 // Both BIOS and OS wants 64bit vector
120 if (FeaturePcdGet (PcdDxeIplSwitchToLongMode)) {
121 return TRUE;
122 }
123 }
124 }
125 return FALSE;
126 }
127
128 /**
129 Set a IDT entry for interrupt vector 3 for debug purpose.
130
131 @param AcpiS3Context a pointer to a structure of ACPI_S3_CONTEXT
132
133 **/
134 VOID
SetIdtEntry(IN ACPI_S3_CONTEXT * AcpiS3Context)135 SetIdtEntry (
136 IN ACPI_S3_CONTEXT *AcpiS3Context
137 )
138 {
139 IA32_IDT_GATE_DESCRIPTOR *IdtEntry;
140 IA32_DESCRIPTOR *IdtDescriptor;
141 UINTN S3DebugBuffer;
142 EFI_STATUS Status;
143
144 //
145 // Restore IDT for debug
146 //
147 IdtDescriptor = (IA32_DESCRIPTOR *) (UINTN) (AcpiS3Context->IdtrProfile);
148 AsmWriteIdtr (IdtDescriptor);
149
150 //
151 // Setup the default CPU exception handlers
152 //
153 Status = InitializeCpuExceptionHandlers (NULL);
154 ASSERT_EFI_ERROR (Status);
155
156 DEBUG_CODE (
157 //
158 // Update IDT entry INT3 if the instruction is valid in it
159 //
160 S3DebugBuffer = (UINTN) (AcpiS3Context->S3DebugBufferAddress);
161 if (*(UINTN *)S3DebugBuffer != (UINTN) -1) {
162 IdtEntry = (IA32_IDT_GATE_DESCRIPTOR *)(IdtDescriptor->Base + (3 * sizeof (IA32_IDT_GATE_DESCRIPTOR)));
163 IdtEntry->Bits.OffsetLow = (UINT16)S3DebugBuffer;
164 IdtEntry->Bits.Selector = (UINT16)AsmReadCs ();
165 IdtEntry->Bits.Reserved_0 = 0;
166 IdtEntry->Bits.GateType = IA32_IDT_GATE_TYPE_INTERRUPT_32;
167 IdtEntry->Bits.OffsetHigh = (UINT16)(S3DebugBuffer >> 16);
168 IdtEntry->Bits.OffsetUpper = (UINT32)(S3DebugBuffer >> 32);
169 IdtEntry->Bits.Reserved_1 = 0;
170 }
171 );
172
173 //
174 // If both BIOS and OS wants long mode waking vector,
175 // S3ResumePei should have established 1:1 Virtual to Physical identity mapping page table,
176 // no need to hook page fault handler.
177 //
178 if (!IsLongModeWakingVector (AcpiS3Context)) {
179 IdtEntry = (IA32_IDT_GATE_DESCRIPTOR *)(IdtDescriptor->Base + (14 * sizeof (IA32_IDT_GATE_DESCRIPTOR)));
180 HookPageFaultHandler (IdtEntry);
181 }
182 }
183
184 /**
185 Acquire page for page fault.
186
187 @param[in, out] Uplink Pointer to up page table entry.
188
189 **/
190 VOID
AcquirePage(IN OUT UINT64 * Uplink)191 AcquirePage (
192 IN OUT UINT64 *Uplink
193 )
194 {
195 UINTN Address;
196
197 Address = mPageFaultBuffer + EFI_PAGES_TO_SIZE (mPageFaultIndex);
198 ZeroMem ((VOID *) Address, EFI_PAGES_TO_SIZE (1));
199
200 //
201 // Cut the previous uplink if it exists and wasn't overwritten.
202 //
203 if ((mPageFaultUplink[mPageFaultIndex] != NULL) && ((*mPageFaultUplink[mPageFaultIndex] & mPhyMask) == Address)) {
204 *mPageFaultUplink[mPageFaultIndex] = 0;
205 }
206
207 //
208 // Link & Record the current uplink.
209 //
210 *Uplink = Address | IA32_PG_P | IA32_PG_RW;
211 mPageFaultUplink[mPageFaultIndex] = Uplink;
212
213 mPageFaultIndex = (mPageFaultIndex + 1) % EXTRA_PAGE_TABLE_PAGES;
214 }
215
216 /**
217 The page fault handler that on-demand read >4G memory/MMIO.
218
219 @retval TRUE The page fault is correctly handled.
220 @retval FALSE The page fault is not handled and is passed through to original handler.
221
222 **/
223 BOOLEAN
224 EFIAPI
PageFaultHandler(VOID)225 PageFaultHandler (
226 VOID
227 )
228 {
229 UINT64 *PageTable;
230 UINT64 PFAddress;
231 UINTN PTIndex;
232
233 PFAddress = AsmReadCr2 ();
234 DEBUG ((EFI_D_ERROR, "BootScript - PageFaultHandler: Cr2 - %lx\n", PFAddress));
235
236 if (PFAddress >= mPhyMask + SIZE_4KB) {
237 return FALSE;
238 }
239 PFAddress &= mPhyMask;
240
241 PageTable = (UINT64*)(UINTN)(AsmReadCr3 () & mPhyMask);
242
243 PTIndex = BitFieldRead64 (PFAddress, 39, 47);
244 // PML4E
245 if ((PageTable[PTIndex] & IA32_PG_P) == 0) {
246 AcquirePage (&PageTable[PTIndex]);
247 }
248 PageTable = (UINT64*)(UINTN)(PageTable[PTIndex] & mPhyMask);
249 PTIndex = BitFieldRead64 (PFAddress, 30, 38);
250 // PDPTE
251 if (mPage1GSupport) {
252 PageTable[PTIndex] = (PFAddress & ~((1ull << 30) - 1)) | IA32_PG_P | IA32_PG_RW | IA32_PG_PS;
253 } else {
254 if ((PageTable[PTIndex] & IA32_PG_P) == 0) {
255 AcquirePage (&PageTable[PTIndex]);
256 }
257 PageTable = (UINT64*)(UINTN)(PageTable[PTIndex] & mPhyMask);
258 PTIndex = BitFieldRead64 (PFAddress, 21, 29);
259 // PD
260 PageTable[PTIndex] = (PFAddress & ~((1ull << 21) - 1)) | IA32_PG_P | IA32_PG_RW | IA32_PG_PS;
261 }
262
263 return TRUE;
264 }
265