// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// Several simple types used by the disassembler and some of the patching
// mechanisms.
#ifndef SANDBOX_SRC_SIDESTEP_MINI_DISASSEMBLER_TYPES_H__
#define SANDBOX_SRC_SIDESTEP_MINI_DISASSEMBLER_TYPES_H__
namespace sidestep {
// Categories of instructions that we care about
enum InstructionType {
// This opcode is not used
IT_UNUSED,
// This disassembler does not recognize this opcode (error)
IT_UNKNOWN,
// This is not an instruction but a reference to another table
IT_REFERENCE,
// This byte is a prefix byte that we can ignore
IT_PREFIX,
// This is a prefix byte that switches to the nondefault address size
IT_PREFIX_ADDRESS,
// This is a prefix byte that switches to the nondefault operand size
IT_PREFIX_OPERAND,
// A jump or call instruction
IT_JUMP,
// A return instruction
IT_RETURN,
// Any other type of instruction (in this case we don't care what it is)
IT_GENERIC,
};
// Lists IA-32 operand sizes in multiples of 8 bits
enum OperandSize {
OS_ZERO = 0,
OS_BYTE = 1,
OS_WORD = 2,
OS_DOUBLE_WORD = 4,
OS_QUAD_WORD = 8,
OS_DOUBLE_QUAD_WORD = 16,
OS_32_BIT_POINTER = 32/8,
OS_48_BIT_POINTER = 48/8,
OS_SINGLE_PRECISION_FLOATING = 32/8,
OS_DOUBLE_PRECISION_FLOATING = 64/8,
OS_DOUBLE_EXTENDED_PRECISION_FLOATING = 80/8,
OS_128_BIT_PACKED_SINGLE_PRECISION_FLOATING = 128/8,
OS_PSEUDO_DESCRIPTOR = 6
};
// Operand addressing methods from the IA-32 manual. The enAmMask value
// is a mask for the rest. The other enumeration values are named for the
// names given to the addressing methods in the manual, e.g. enAm_D is for
// the D addressing method.
//
// The reason we use a full 4 bytes and a mask, is that we need to combine
// these flags with the enOperandType to store the details
// on the operand in a single integer.
enum AddressingMethod {
AM_NOT_USED = 0, // This operand is not used for this instruction
AM_MASK = 0x00FF0000, // Mask for the rest of the values in this enumeration
AM_A = 0x00010000, // A addressing type
AM_C = 0x00020000, // C addressing type
AM_D = 0x00030000, // D addressing type
AM_E = 0x00040000, // E addressing type
AM_F = 0x00050000, // F addressing type
AM_G = 0x00060000, // G addressing type
AM_I = 0x00070000, // I addressing type
AM_J = 0x00080000, // J addressing type
AM_M = 0x00090000, // M addressing type
AM_O = 0x000A0000, // O addressing type
AM_P = 0x000B0000, // P addressing type
AM_Q = 0x000C0000, // Q addressing type
AM_R = 0x000D0000, // R addressing type
AM_S = 0x000E0000, // S addressing type
AM_T = 0x000F0000, // T addressing type
AM_V = 0x00100000, // V addressing type
AM_W = 0x00110000, // W addressing type
AM_X = 0x00120000, // X addressing type
AM_Y = 0x00130000, // Y addressing type
AM_REGISTER = 0x00140000, // Specific register is always used as this op
AM_IMPLICIT = 0x00150000, // An implicit, fixed value is used
};
// Operand types from the IA-32 manual. The enOtMask value is
// a mask for the rest. The rest of the values are named for the
// names given to these operand types in the manual, e.g. enOt_ps
// is for the ps operand type in the manual.
//
// The reason we use a full 4 bytes and a mask, is that we need
// to combine these flags with the enAddressingMethod to store the details
// on the operand in a single integer.
enum OperandType {
OT_MASK = 0xFF000000,
OT_A = 0x01000000,
OT_B = 0x02000000,
OT_C = 0x03000000,
OT_D = 0x04000000,
OT_DQ = 0x05000000,
OT_P = 0x06000000,
OT_PI = 0x07000000,
OT_PS = 0x08000000, // actually unsupported for (we don't know its size)
OT_Q = 0x09000000,
OT_S = 0x0A000000,
OT_SS = 0x0B000000,
OT_SI = 0x0C000000,
OT_V = 0x0D000000,
OT_W = 0x0E000000,
OT_SD = 0x0F000000, // scalar double-precision floating-point value
OT_PD = 0x10000000, // double-precision floating point
// dummy "operand type" for address mode M - which doesn't specify
// operand type
OT_ADDRESS_MODE_M = 0x80000000
};
// Everything that's in an Opcode (see below) except the three
// alternative opcode structs for different prefixes.
struct SpecificOpcode {
// Index to continuation table, or 0 if this is the last
// byte in the opcode.
int table_index_;
// The opcode type
InstructionType type_;
// Description of the type of the dest, src and aux operands,
// put together from an enOperandType flag and an enAddressingMethod
// flag.
int flag_dest_;
int flag_source_;
int flag_aux_;
// We indicate the mnemonic for debugging purposes
const char* mnemonic_;
};
// The information we keep in our tables about each of the different
// valid instructions recognized by the IA-32 architecture.
struct Opcode {
// Index to continuation table, or 0 if this is the last
// byte in the opcode.
int table_index_;
// The opcode type
InstructionType type_;
// Description of the type of the dest, src and aux operands,
// put together from an enOperandType flag and an enAddressingMethod
// flag.
int flag_dest_;
int flag_source_;
int flag_aux_;
// We indicate the mnemonic for debugging purposes
const char* mnemonic_;
// Alternative opcode info if certain prefixes are specified.
// In most cases, all of these are zeroed-out. Only used if
// bPrefixDependent is true.
bool is_prefix_dependent_;
SpecificOpcode opcode_if_f2_prefix_;
SpecificOpcode opcode_if_f3_prefix_;
SpecificOpcode opcode_if_66_prefix_;
};
// Information about each table entry.
struct OpcodeTable {
// Table of instruction entries
const Opcode* table_;
// How many bytes left to shift ModR/M byte <b>before</b> applying mask
unsigned char shift_;
// Mask to apply to byte being looked at before comparing to table
unsigned char mask_;
// Minimum/maximum indexes in table.
unsigned char min_lim_;
unsigned char max_lim_;
};
// Information about each entry in table used to decode ModR/M byte.
struct ModrmEntry {
// Is the operand encoded as bytes in the instruction (rather than
// if it's e.g. a register in which case it's just encoded in the
// ModR/M byte)
bool is_encoded_in_instruction_;
// Is there a SIB byte? In this case we always need to decode it.
bool use_sib_byte_;
// What is the size of the operand (only important if it's encoded
// in the instruction)?
OperandSize operand_size_;
};
}; // namespace sidestep
#endif // SANDBOX_SRC_SIDESTEP_MINI_DISASSEMBLER_TYPES_H__