1 /** @file
2 Default exception handler
3
4 Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
5 Copyright (c) 2012, ARM Ltd. All rights reserved.<BR>
6
7 This program and the accompanying materials
8 are licensed and made available under the terms and conditions of the BSD License
9 which accompanies this distribution. The full text of the license may be found at
10 http://opensource.org/licenses/bsd-license.php
11
12 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
13 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
14
15 **/
16
17 #include <Uefi.h>
18 #include <Library/BaseLib.h>
19 #include <Library/DebugLib.h>
20 #include <Library/PeCoffGetEntryPointLib.h>
21 #include <Library/PrintLib.h>
22 #include <Library/ArmDisassemblerLib.h>
23 #include <Library/SerialPortLib.h>
24
25 #include <Guid/DebugImageInfoTable.h>
26
27 #include <Protocol/DebugSupport.h>
28 #include <Library/DefaultExceptionHandlerLib.h>
29
30 //
31 // The number of elements in a CHAR8 array, including the terminating NUL, that
32 // is meant to hold the string rendering of the CPSR.
33 //
34 #define CPSR_STRING_SIZE 32
35
36 typedef struct {
37 UINT32 BIT;
38 CHAR8 Char;
39 } CPSR_CHAR;
40
41 CHAR8 *
42 GetImageName (
43 IN UINTN FaultAddress,
44 OUT UINTN *ImageBase,
45 OUT UINTN *PeCoffSizeOfHeaders
46 );
47
48 /**
49 Convert the Current Program Status Register (CPSR) to a string. The string is
50 a defacto standard in the ARM world.
51
52 It is possible to add extra bits by adding them to CpsrChar array.
53
54 @param Cpsr ARM CPSR register value
55 @param ReturnStr CPSR_STRING_SIZE byte string that contains string
56 version of CPSR
57
58 **/
59 VOID
CpsrString(IN UINT32 Cpsr,OUT CHAR8 * ReturnStr)60 CpsrString (
61 IN UINT32 Cpsr,
62 OUT CHAR8 *ReturnStr
63 )
64 {
65 UINTN Index;
66 CHAR8* Str;
67 CHAR8* ModeStr;
68 CPSR_CHAR CpsrChar[] = {
69 { 31, 'n' },
70 { 30, 'z' },
71 { 29, 'c' },
72 { 28, 'v' },
73
74 { 9, 'e' },
75 { 8, 'a' },
76 { 7, 'i' },
77 { 6, 'f' },
78 { 5, 't' },
79 { 0, '?' }
80 };
81
82 Str = ReturnStr;
83
84 for (Index = 0; CpsrChar[Index].BIT != 0; Index++, Str++) {
85 *Str = CpsrChar[Index].Char;
86 if ((Cpsr & (1 << CpsrChar[Index].BIT)) != 0) {
87 // Concert to upper case if bit is set
88 *Str &= ~0x20;
89 }
90 }
91
92 *Str++ = '_';
93 *Str = '\0';
94
95 switch (Cpsr & 0x1f) {
96 case 0x10:
97 ModeStr = "usr";
98 break;
99 case 0x011:
100 ModeStr = "fiq";
101 break;
102 case 0x12:
103 ModeStr = "irq";
104 break;
105 case 0x13:
106 ModeStr = "svc";
107 break;
108 case 0x16:
109 ModeStr = "mon";
110 break;
111 case 0x17:
112 ModeStr = "abt";
113 break;
114 case 0x1b:
115 ModeStr = "und";
116 break;
117 case 0x1f:
118 ModeStr = "sys";
119 break;
120
121 default:
122 ModeStr = "???";
123 break;
124 }
125
126 //
127 // See the interface contract in the leading comment block.
128 //
129 AsciiStrCatS (Str, CPSR_STRING_SIZE - (Str - ReturnStr), ModeStr);
130 }
131
132 CHAR8 *
FaultStatusToString(IN UINT32 Status)133 FaultStatusToString (
134 IN UINT32 Status
135 )
136 {
137 CHAR8 *FaultSource;
138
139 switch (Status) {
140 case 0x01: FaultSource = "Alignment fault"; break;
141 case 0x02: FaultSource = "Debug event fault"; break;
142 case 0x03: FaultSource = "Access Flag fault on Section"; break;
143 case 0x04: FaultSource = "Cache maintenance operation fault[2]"; break;
144 case 0x05: FaultSource = "Translation fault on Section"; break;
145 case 0x06: FaultSource = "Access Flag fault on Page"; break;
146 case 0x07: FaultSource = "Translation fault on Page"; break;
147 case 0x08: FaultSource = "Precise External Abort"; break;
148 case 0x09: FaultSource = "Domain fault on Section"; break;
149 case 0x0b: FaultSource = "Domain fault on Page"; break;
150 case 0x0c: FaultSource = "External abort on translation, first level"; break;
151 case 0x0d: FaultSource = "Permission fault on Section"; break;
152 case 0x0e: FaultSource = "External abort on translation, second level"; break;
153 case 0x0f: FaultSource = "Permission fault on Page"; break;
154 case 0x16: FaultSource = "Imprecise External Abort"; break;
155 default: FaultSource = "No function"; break;
156 }
157
158 return FaultSource;
159 }
160
161 STATIC CHAR8 *gExceptionTypeString[] = {
162 "Reset",
163 "Undefined OpCode",
164 "SVC",
165 "Prefetch Abort",
166 "Data Abort",
167 "Undefined",
168 "IRQ",
169 "FIQ"
170 };
171
172 /**
173 This is the default action to take on an unexpected exception
174
175 Since this is exception context don't do anything crazy like try to allcoate memory.
176
177 @param ExceptionType Type of the exception
178 @param SystemContext Register state at the time of the Exception
179
180
181 **/
182 VOID
DefaultExceptionHandler(IN EFI_EXCEPTION_TYPE ExceptionType,IN OUT EFI_SYSTEM_CONTEXT SystemContext)183 DefaultExceptionHandler (
184 IN EFI_EXCEPTION_TYPE ExceptionType,
185 IN OUT EFI_SYSTEM_CONTEXT SystemContext
186 )
187 {
188 CHAR8 Buffer[100];
189 UINTN CharCount;
190 UINT32 DfsrStatus;
191 UINT32 IfsrStatus;
192 BOOLEAN DfsrWrite;
193 UINT32 PcAdjust = 0;
194
195 CharCount = AsciiSPrint (Buffer,sizeof (Buffer),"\n%a Exception PC at 0x%08x CPSR 0x%08x ",
196 gExceptionTypeString[ExceptionType], SystemContext.SystemContextArm->PC, SystemContext.SystemContextArm->CPSR);
197 SerialPortWrite ((UINT8 *) Buffer, CharCount);
198
199 DEBUG_CODE_BEGIN ();
200 CHAR8 *Pdb;
201 UINT32 ImageBase;
202 UINT32 PeCoffSizeOfHeader;
203 UINT32 Offset;
204 CHAR8 CpsrStr[CPSR_STRING_SIZE]; // char per bit. Lower 5-bits are mode
205 // that is a 3 char string
206 CHAR8 Buffer[80];
207 UINT8 *DisAsm;
208 UINT32 ItBlock;
209
210 CpsrString (SystemContext.SystemContextArm->CPSR, CpsrStr);
211 DEBUG ((EFI_D_ERROR, "%a\n", CpsrStr));
212
213 Pdb = GetImageName (SystemContext.SystemContextArm->PC, &ImageBase, &PeCoffSizeOfHeader);
214 Offset = SystemContext.SystemContextArm->PC - ImageBase;
215 if (Pdb != NULL) {
216 DEBUG ((EFI_D_ERROR, "%a\n", Pdb));
217
218 //
219 // A PE/COFF image loads its headers into memory so the headers are
220 // included in the linked addresses. ELF and Mach-O images do not
221 // include the headers so the first byte of the image is usually
222 // text (code). If you look at link maps from ELF or Mach-O images
223 // you need to subtract out the size of the PE/COFF header to get
224 // get the offset that matches the link map.
225 //
226 DEBUG ((EFI_D_ERROR, "loaded at 0x%08x (PE/COFF offset) 0x%x (ELF or Mach-O offset) 0x%x", ImageBase, Offset, Offset - PeCoffSizeOfHeader));
227
228 // If we come from an image it is safe to show the instruction. We know it should not fault
229 DisAsm = (UINT8 *)(UINTN)SystemContext.SystemContextArm->PC;
230 ItBlock = 0;
231 DisassembleInstruction (&DisAsm, (SystemContext.SystemContextArm->CPSR & BIT5) == BIT5, TRUE, &ItBlock, Buffer, sizeof (Buffer));
232 DEBUG ((EFI_D_ERROR, "\n%a", Buffer));
233
234 switch (ExceptionType) {
235 case EXCEPT_ARM_UNDEFINED_INSTRUCTION:
236 case EXCEPT_ARM_SOFTWARE_INTERRUPT:
237 case EXCEPT_ARM_PREFETCH_ABORT:
238 case EXCEPT_ARM_DATA_ABORT:
239 // advance PC past the faulting instruction
240 PcAdjust = (UINTN)DisAsm - SystemContext.SystemContextArm->PC;
241 break;
242
243 default:
244 break;
245 }
246
247 }
248 DEBUG_CODE_END ();
249 DEBUG ((EFI_D_ERROR, "\n R0 0x%08x R1 0x%08x R2 0x%08x R3 0x%08x\n", SystemContext.SystemContextArm->R0, SystemContext.SystemContextArm->R1, SystemContext.SystemContextArm->R2, SystemContext.SystemContextArm->R3));
250 DEBUG ((EFI_D_ERROR, " R4 0x%08x R5 0x%08x R6 0x%08x R7 0x%08x\n", SystemContext.SystemContextArm->R4, SystemContext.SystemContextArm->R5, SystemContext.SystemContextArm->R6, SystemContext.SystemContextArm->R7));
251 DEBUG ((EFI_D_ERROR, " R8 0x%08x R9 0x%08x R10 0x%08x R11 0x%08x\n", SystemContext.SystemContextArm->R8, SystemContext.SystemContextArm->R9, SystemContext.SystemContextArm->R10, SystemContext.SystemContextArm->R11));
252 DEBUG ((EFI_D_ERROR, " R12 0x%08x SP 0x%08x LR 0x%08x PC 0x%08x\n", SystemContext.SystemContextArm->R12, SystemContext.SystemContextArm->SP, SystemContext.SystemContextArm->LR, SystemContext.SystemContextArm->PC));
253 DEBUG ((EFI_D_ERROR, "DFSR 0x%08x DFAR 0x%08x IFSR 0x%08x IFAR 0x%08x\n", SystemContext.SystemContextArm->DFSR, SystemContext.SystemContextArm->DFAR, SystemContext.SystemContextArm->IFSR, SystemContext.SystemContextArm->IFAR));
254
255 // Bit10 is Status[4] Bit3:0 is Status[3:0]
256 DfsrStatus = (SystemContext.SystemContextArm->DFSR & 0xf) | ((SystemContext.SystemContextArm->DFSR >> 6) & 0x10);
257 DfsrWrite = (SystemContext.SystemContextArm->DFSR & BIT11) != 0;
258 if (DfsrStatus != 0x00) {
259 DEBUG ((EFI_D_ERROR, " %a: %a 0x%08x\n", FaultStatusToString (DfsrStatus), DfsrWrite ? "write to" : "read from", SystemContext.SystemContextArm->DFAR));
260 }
261
262 IfsrStatus = (SystemContext.SystemContextArm->IFSR & 0xf) | ((SystemContext.SystemContextArm->IFSR >> 6) & 0x10);
263 if (IfsrStatus != 0) {
264 DEBUG ((EFI_D_ERROR, " Instruction %a at 0x%08x\n", FaultStatusToString (SystemContext.SystemContextArm->IFSR & 0xf), SystemContext.SystemContextArm->IFAR));
265 }
266
267 DEBUG ((EFI_D_ERROR, "\n"));
268 ASSERT (FALSE);
269
270 // Clear the error registers that we have already displayed incase some one wants to keep going
271 SystemContext.SystemContextArm->DFSR = 0;
272 SystemContext.SystemContextArm->IFSR = 0;
273
274 // If some one is stepping past the exception handler adjust the PC to point to the next instruction
275 SystemContext.SystemContextArm->PC += PcAdjust;
276 }
277