CloverBootloader/MdePkg/Library/BasePeCoffLib/Arm/PeCoffLoaderEx.c

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/** @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;
}