/** @file | |
Specific relocation fixups for ARM architecture. | |
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR> | |
Portions copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR> | |
SPDX-License-Identifier: BSD-2-Clause-Patent | |
**/ | |
#include "BasePeCoffLibInternals.h" | |
#include <Library/BaseLib.h> | |
/** | |
Pass in a pointer to an ARM MOVT or MOVW immediate instruciton and | |
return the immediate data encoded in the instruction. | |
@param Instruction Pointer to ARM MOVT or MOVW immediate instruction | |
@return Immediate address encoded in the instruction | |
**/ | |
UINT16 | |
ThumbMovtImmediateAddress ( | |
IN UINT16 *Instruction | |
) | |
{ | |
UINT32 Movt; | |
UINT16 Address; | |
// Thumb2 is two 16-bit instructions working together. Not a single 32-bit instruction | |
// Example MOVT R0, #0 is 0x0000f2c0 or 0xf2c0 0x0000 | |
Movt = (*Instruction << 16) | (*(Instruction + 1)); | |
// imm16 = imm4:i:imm3:imm8 | |
// imm4 -> Bit19:Bit16 | |
// i -> Bit26 | |
// imm3 -> Bit14:Bit12 | |
// imm8 -> Bit7:Bit0 | |
Address = (UINT16)(Movt & 0x000000ff); // imm8 | |
Address |= (UINT16)((Movt >> 4) & 0x0000f700); // imm4 imm3 | |
Address |= (((Movt & BIT26) != 0) ? BIT11 : 0); // i | |
return Address; | |
} | |
/** | |
Update an ARM MOVT or MOVW immediate instruction immediate data. | |
@param Instruction Pointer to ARM MOVT or MOVW immediate instruction | |
@param Address New addres to patch into the instruction | |
**/ | |
VOID | |
ThumbMovtImmediatePatch ( | |
IN OUT UINT16 *Instruction, | |
IN UINT16 Address | |
) | |
{ | |
UINT16 Patch; | |
// First 16-bit chunk of instruciton | |
Patch = ((Address >> 12) & 0x000f); // imm4 | |
Patch |= (((Address & BIT11) != 0) ? BIT10 : 0); // i | |
// Mask out instruction bits and or in address | |
*(Instruction) = (*Instruction & ~0x040f) | Patch; | |
// Second 16-bit chunk of instruction | |
Patch = Address & 0x000000ff; // imm8 | |
Patch |= ((Address << 4) & 0x00007000); // imm3 | |
// Mask out instruction bits and or in address | |
Instruction++; | |
*Instruction = (*Instruction & ~0x70ff) | Patch; | |
} | |
/** | |
Pass in a pointer to an ARM MOVW/MOVT instruciton pair and | |
return the immediate data encoded in the two` instruction. | |
@param Instructions Pointer to ARM MOVW/MOVT insturction pair | |
@return Immediate address encoded in the instructions | |
**/ | |
UINT32 | |
ThumbMovwMovtImmediateAddress ( | |
IN UINT16 *Instructions | |
) | |
{ | |
UINT16 *Word; | |
UINT16 *Top; | |
Word = Instructions; // MOVW | |
Top = Word + 2; // MOVT | |
return (ThumbMovtImmediateAddress (Top) << 16) + ThumbMovtImmediateAddress (Word); | |
} | |
/** | |
Update an ARM MOVW/MOVT immediate instruction instruction pair. | |
@param Instructions Pointer to ARM MOVW/MOVT instruction pair | |
@param Address New addres to patch into the instructions | |
**/ | |
VOID | |
ThumbMovwMovtImmediatePatch ( | |
IN OUT UINT16 *Instructions, | |
IN UINT32 Address | |
) | |
{ | |
UINT16 *Word; | |
UINT16 *Top; | |
Word = Instructions; // MOVW | |
Top = Word + 2; // MOVT | |
ThumbMovtImmediatePatch (Word, (UINT16)(Address & 0xffff)); | |
ThumbMovtImmediatePatch (Top, (UINT16)(Address >> 16)); | |
} | |
/** | |
Performs an ARM-based specific relocation fixup and is a no-op on other | |
instruction sets. | |
@param Reloc The pointer to the relocation record. | |
@param Fixup The pointer to the address to fix up. | |
@param FixupData The pointer to a buffer to log the fixups. | |
@param Adjust The offset to adjust the fixup. | |
@return Status code. | |
**/ | |
RETURN_STATUS | |
PeCoffLoaderRelocateImageEx ( | |
IN UINT16 *Reloc, | |
IN OUT CHAR8 *Fixup, | |
IN OUT CHAR8 **FixupData, | |
IN UINT64 Adjust | |
) | |
{ | |
UINT16 *Fixup16; | |
UINT32 FixupVal; | |
Fixup16 = (UINT16 *) Fixup; | |
switch ((*Reloc) >> 12) { | |
case EFI_IMAGE_REL_BASED_ARM_MOV32T: | |
FixupVal = ThumbMovwMovtImmediateAddress (Fixup16) + (UINT32)Adjust; | |
ThumbMovwMovtImmediatePatch (Fixup16, FixupVal); | |
if (*FixupData != NULL) { | |
*FixupData = ALIGN_POINTER(*FixupData, sizeof(UINT64)); | |
// Fixup16 is not aligned so we must copy it. Thumb instructions are streams of 16 bytes. | |
CopyMem (*FixupData, Fixup16, sizeof (UINT64)); | |
*FixupData = *FixupData + sizeof(UINT64); | |
} | |
break; | |
case EFI_IMAGE_REL_BASED_ARM_MOV32A: | |
ASSERT (FALSE); | |
// break omitted - ARM instruction encoding not implemented | |
default: | |
return RETURN_UNSUPPORTED; | |
} | |
return RETURN_SUCCESS; | |
} | |
/** | |
Returns TRUE if the machine type of PE/COFF image is supported. Supported | |
does not mean the image can be executed it means the PE/COFF loader supports | |
loading and relocating of the image type. It's up to the caller to support | |
the entry point. | |
@param Machine Machine type from the PE Header. | |
@return TRUE if this PE/COFF loader can load the image | |
**/ | |
BOOLEAN | |
PeCoffLoaderImageFormatSupported ( | |
IN UINT16 Machine | |
) | |
{ | |
if ((Machine == IMAGE_FILE_MACHINE_ARMTHUMB_MIXED) || (Machine == IMAGE_FILE_MACHINE_EBC)) { | |
return TRUE; | |
} | |
return FALSE; | |
} | |
/** | |
Performs an ARM-based specific re-relocation fixup and is a no-op on other | |
instruction sets. This is used to re-relocated the image into the EFI virtual | |
space for runtime calls. | |
@param Reloc The pointer to the relocation record. | |
@param Fixup The pointer to the address to fix up. | |
@param FixupData The pointer to a buffer to log the fixups. | |
@param Adjust The offset to adjust the fixup. | |
@return Status code. | |
**/ | |
RETURN_STATUS | |
PeHotRelocateImageEx ( | |
IN UINT16 *Reloc, | |
IN OUT CHAR8 *Fixup, | |
IN OUT CHAR8 **FixupData, | |
IN UINT64 Adjust | |
) | |
{ | |
UINT16 *Fixup16; | |
UINT32 FixupVal; | |
Fixup16 = (UINT16 *)Fixup; | |
switch ((*Reloc) >> 12) { | |
case EFI_IMAGE_REL_BASED_ARM_MOV32T: | |
*FixupData = ALIGN_POINTER (*FixupData, sizeof (UINT64)); | |
if (*(UINT64 *) (*FixupData) == ReadUnaligned64 ((UINT64 *)Fixup16)) { | |
FixupVal = ThumbMovwMovtImmediateAddress (Fixup16) + (UINT32)Adjust; | |
ThumbMovwMovtImmediatePatch (Fixup16, FixupVal); | |
} | |
*FixupData = *FixupData + sizeof(UINT64); | |
break; | |
case EFI_IMAGE_REL_BASED_ARM_MOV32A: | |
ASSERT (FALSE); | |
// break omitted - ARM instruction encoding not implemented | |
default: | |
DEBUG ((EFI_D_ERROR, "PeHotRelocateEx:unknown fixed type\n")); | |
return RETURN_UNSUPPORTED; | |
} | |
return RETURN_SUCCESS; | |
} | |