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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>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#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 <Library/UefiBootServicesTableLib.h>
#include <Library/UefiLib.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);
if (gST->ConOut != NULL) {
AsciiPrint (Buffer);
}
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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