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/** @file
Default exception handler
Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
Copyright (c) 2012, ARM Ltd. All rights reserved.<BR>
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 <Uefi.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/PeCoffGetEntryPointLib.h>
#include <Library/PrintLib.h>
#include <Library/ArmDisassemblerLib.h>
#include <Library/SerialPortLib.h>
#include <Guid/DebugImageInfoTable.h>
#include <Protocol/DebugSupport.h>
#include <Library/DefaultExceptionHandlerLib.h>
//
// The number of elements in a CHAR8 array, including the terminating NUL, that
// is meant to hold the string rendering of the CPSR.
//
#define CPSR_STRING_SIZE 32
typedef struct {
UINT32 BIT;
CHAR8 Char;
} CPSR_CHAR;
CHAR8 *
GetImageName (
IN UINTN FaultAddress,
OUT UINTN *ImageBase,
OUT UINTN *PeCoffSizeOfHeaders
);
/**
Convert the Current Program Status Register (CPSR) to a string. The string is
a defacto standard in the ARM world.
It is possible to add extra bits by adding them to CpsrChar array.
@param Cpsr ARM CPSR register value
@param ReturnStr CPSR_STRING_SIZE byte string that contains string
version of CPSR
**/
VOID
CpsrString (
IN UINT32 Cpsr,
OUT CHAR8 *ReturnStr
)
{
UINTN Index;
CHAR8* Str;
CHAR8* ModeStr;
CPSR_CHAR CpsrChar[] = {
{ 31, 'n' },
{ 30, 'z' },
{ 29, 'c' },
{ 28, 'v' },
{ 9, 'e' },
{ 8, 'a' },
{ 7, 'i' },
{ 6, 'f' },
{ 5, 't' },
{ 0, '?' }
};
Str = ReturnStr;
for (Index = 0; CpsrChar[Index].BIT != 0; Index++, Str++) {
*Str = CpsrChar[Index].Char;
if ((Cpsr & (1 << CpsrChar[Index].BIT)) != 0) {
// Concert to upper case if bit is set
*Str &= ~0x20;
}
}
*Str++ = '_';
*Str = '\0';
switch (Cpsr & 0x1f) {
case 0x10:
ModeStr = "usr";
break;
case 0x011:
ModeStr = "fiq";
break;
case 0x12:
ModeStr = "irq";
break;
case 0x13:
ModeStr = "svc";
break;
case 0x16:
ModeStr = "mon";
break;
case 0x17:
ModeStr = "abt";
break;
case 0x1b:
ModeStr = "und";
break;
case 0x1f:
ModeStr = "sys";
break;
default:
ModeStr = "???";
break;
}
//
// See the interface contract in the leading comment block.
//
AsciiStrCatS (Str, CPSR_STRING_SIZE - (Str - ReturnStr), ModeStr);
}
CHAR8 *
FaultStatusToString (
IN UINT32 Status
)
{
CHAR8 *FaultSource;
switch (Status) {
case 0x01: FaultSource = "Alignment fault"; break;
case 0x02: FaultSource = "Debug event fault"; break;
case 0x03: FaultSource = "Access Flag fault on Section"; break;
case 0x04: FaultSource = "Cache maintenance operation fault[2]"; break;
case 0x05: FaultSource = "Translation fault on Section"; break;
case 0x06: FaultSource = "Access Flag fault on Page"; break;
case 0x07: FaultSource = "Translation fault on Page"; break;
case 0x08: FaultSource = "Precise External Abort"; break;
case 0x09: FaultSource = "Domain fault on Section"; break;
case 0x0b: FaultSource = "Domain fault on Page"; break;
case 0x0c: FaultSource = "External abort on translation, first level"; break;
case 0x0d: FaultSource = "Permission fault on Section"; break;
case 0x0e: FaultSource = "External abort on translation, second level"; break;
case 0x0f: FaultSource = "Permission fault on Page"; break;
case 0x16: FaultSource = "Imprecise External Abort"; break;
default: FaultSource = "No function"; break;
}
return FaultSource;
}
STATIC CHAR8 *gExceptionTypeString[] = {
"Reset",
"Undefined OpCode",
"SVC",
"Prefetch Abort",
"Data Abort",
"Undefined",
"IRQ",
"FIQ"
};
/**
This is the default action to take on an unexpected exception
Since this is exception context don't do anything crazy like try to allcoate memory.
@param ExceptionType Type of the exception
@param SystemContext Register state at the time of the Exception
**/
VOID
DefaultExceptionHandler (
IN EFI_EXCEPTION_TYPE ExceptionType,
IN OUT EFI_SYSTEM_CONTEXT SystemContext
)
{
CHAR8 Buffer[100];
UINTN CharCount;
UINT32 DfsrStatus;
UINT32 IfsrStatus;
BOOLEAN DfsrWrite;
UINT32 PcAdjust = 0;
CharCount = AsciiSPrint (Buffer,sizeof (Buffer),"\n%a Exception PC at 0x%08x CPSR 0x%08x ",
gExceptionTypeString[ExceptionType], SystemContext.SystemContextArm->PC, SystemContext.SystemContextArm->CPSR);
SerialPortWrite ((UINT8 *) Buffer, CharCount);
DEBUG_CODE_BEGIN ();
CHAR8 *Pdb;
UINT32 ImageBase;
UINT32 PeCoffSizeOfHeader;
UINT32 Offset;
CHAR8 CpsrStr[CPSR_STRING_SIZE]; // char per bit. Lower 5-bits are mode
// that is a 3 char string
CHAR8 Buffer[80];
UINT8 *DisAsm;
UINT32 ItBlock;
CpsrString (SystemContext.SystemContextArm->CPSR, CpsrStr);
DEBUG ((EFI_D_ERROR, "%a\n", CpsrStr));
Pdb = GetImageName (SystemContext.SystemContextArm->PC, &ImageBase, &PeCoffSizeOfHeader);
Offset = SystemContext.SystemContextArm->PC - ImageBase;
if (Pdb != NULL) {
DEBUG ((EFI_D_ERROR, "%a\n", Pdb));
//
// A PE/COFF image loads its headers into memory so the headers are
// included in the linked addresses. ELF and Mach-O images do not
// include the headers so the first byte of the image is usually
// text (code). If you look at link maps from ELF or Mach-O images
// you need to subtract out the size of the PE/COFF header to get
// get the offset that matches the link map.
//
DEBUG ((EFI_D_ERROR, "loaded at 0x%08x (PE/COFF offset) 0x%x (ELF or Mach-O offset) 0x%x", ImageBase, Offset, Offset - PeCoffSizeOfHeader));
// If we come from an image it is safe to show the instruction. We know it should not fault
DisAsm = (UINT8 *)(UINTN)SystemContext.SystemContextArm->PC;
ItBlock = 0;
DisassembleInstruction (&DisAsm, (SystemContext.SystemContextArm->CPSR & BIT5) == BIT5, TRUE, &ItBlock, Buffer, sizeof (Buffer));
DEBUG ((EFI_D_ERROR, "\n%a", Buffer));
switch (ExceptionType) {
case EXCEPT_ARM_UNDEFINED_INSTRUCTION:
case EXCEPT_ARM_SOFTWARE_INTERRUPT:
case EXCEPT_ARM_PREFETCH_ABORT:
case EXCEPT_ARM_DATA_ABORT:
// advance PC past the faulting instruction
PcAdjust = (UINTN)DisAsm - SystemContext.SystemContextArm->PC;
break;
default:
break;
}
}
DEBUG_CODE_END ();
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));
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));
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));
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));
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));
// Bit10 is Status[4] Bit3:0 is Status[3:0]
DfsrStatus = (SystemContext.SystemContextArm->DFSR & 0xf) | ((SystemContext.SystemContextArm->DFSR >> 6) & 0x10);
DfsrWrite = (SystemContext.SystemContextArm->DFSR & BIT11) != 0;
if (DfsrStatus != 0x00) {
DEBUG ((EFI_D_ERROR, " %a: %a 0x%08x\n", FaultStatusToString (DfsrStatus), DfsrWrite ? "write to" : "read from", SystemContext.SystemContextArm->DFAR));
}
IfsrStatus = (SystemContext.SystemContextArm->IFSR & 0xf) | ((SystemContext.SystemContextArm->IFSR >> 6) & 0x10);
if (IfsrStatus != 0) {
DEBUG ((EFI_D_ERROR, " Instruction %a at 0x%08x\n", FaultStatusToString (SystemContext.SystemContextArm->IFSR & 0xf), SystemContext.SystemContextArm->IFAR));
}
DEBUG ((EFI_D_ERROR, "\n"));
ASSERT (FALSE);
CpuDeadLoop (); // may return if executing under a debugger
// Clear the error registers that we have already displayed incase some one wants to keep going
SystemContext.SystemContextArm->DFSR = 0;
SystemContext.SystemContextArm->IFSR = 0;
// If some one is stepping past the exception handler adjust the PC to point to the next instruction
SystemContext.SystemContextArm->PC += PcAdjust;
}
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