marcothms/8086-rs
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

chore: dedup u8/u16 byte/word immediate type

Browse Source
This commit is contained in:
Marco Thomas
2025-05-13 12:44:00 +09:00
parent 27b39ee94a
commit 4443f84297
3 changed files with 97 additions and 124 deletions
Download Patch File Download Diff File Expand all files Collapse all files

127
src/disasm.rs
View File

@@ -2,7 +2,9 @@ use core::fmt;
use std::{fs::File, io::Read, process::exit};
use crate::aout::Aout;
use crate::instructions::{MemoryIndex, ModRmTarget, OperandWidth, RegisterId, SegmentRegister};
use crate::instructions::{
ImmediateOperand, MemoryIndex, ModRmTarget, RegisterId, SegmentRegister,
};
use crate::{
Args,
instructions::{ImmediateByte, ImmediateWord, Instruction, Mnemonic, Register},
@@ -107,7 +109,7 @@ impl Disassembler {
/// Parse a single modrm byte, return the resulting MemoryIndex and advance the offset.
/// Returns the parsed modrm target and the source register
pub fn parse_modrm_byte(&mut self, width: OperandWidth) -> (ModRmTarget, RegisterId) {
pub fn parse_modrm_byte(&mut self, width: ImmediateOperand) -> (ModRmTarget, RegisterId) {
// advance to operand
self.offset += 1;
let modrm = self.text[self.offset];
@@ -128,27 +130,28 @@ impl Disassembler {
0b00 => {
if rm == 0b110 {
log::debug!("Additional word during ModRM parsing was read with mod 0.");
displacement = Some(OperandWidth::Word(self.parse_word()));
displacement = Some(ImmediateOperand::Word(self.parse_word()));
} else {
displacement = None;
}
}
0b01 => {
log::debug!("Additional byte during ModRM parsing was read.");
displacement = Some(OperandWidth::Byte(self.parse_byte()))
displacement = Some(ImmediateOperand::Byte(self.parse_byte()))
}
0b10 => {
log::debug!("Additional word during ModRM parsing was read.");
displacement = Some(OperandWidth::Word(self.parse_word()));
displacement = Some(ImmediateOperand::Word(self.parse_word()));
}
0b11 => {
log::debug!("ModRM to reg");
// XXX: find a nicer way instead of using Byte(0) and Word(0)
let target = match width {
OperandWidth::Byte(_) => {
ModRmTarget::Register(Register::by_id(OperandWidth::Byte(rm)))
ImmediateOperand::Byte(_) => {
ModRmTarget::Register(Register::by_id(ImmediateOperand::Byte(rm)))
}
OperandWidth::Word(_) => {
ModRmTarget::Register(Register::by_id(OperandWidth::Word(rm.into())))
ImmediateOperand::Word(_) => {
ModRmTarget::Register(Register::by_id(ImmediateOperand::Word(rm.into())))
}
};
return (target, reg);
@@ -206,28 +209,28 @@ impl Disassembler {
/// Match the modrm reg bits to the GPR1 mnemonics.
/// GPR always has an imm value as second operand, but is available in both
/// Byte and Word length.
pub fn modrm_reg_to_mnemonic(reg: u8, target: ModRmTarget, imm: OperandWidth) -> Mnemonic {
pub fn modrm_reg_to_mnemonic(reg: u8, target: ModRmTarget, imm: ImmediateOperand) -> Mnemonic {
match imm {
OperandWidth::Byte(b) => match reg {
0b000 => Mnemonic::ADD_Ib(target, ImmediateByte(b)),
0b001 => Mnemonic::OR_Ib(target, ImmediateByte(b)),
0b010 => Mnemonic::ADC_Ib(target, ImmediateByte(b)),
0b011 => Mnemonic::SBB_Ib(target, ImmediateByte(b)),
0b100 => Mnemonic::AND_Ib(target, ImmediateByte(b)),
0b101 => Mnemonic::SUB_Ib(target, ImmediateByte(b)),
0b110 => Mnemonic::XOR_Ib(target, ImmediateByte(b)),
0b111 => Mnemonic::CMP_Ib(target, ImmediateByte(b)),
ImmediateOperand::Byte(b) => match reg {
0b000 => Mnemonic::ADD_Ib(target, b),
0b001 => Mnemonic::OR_Ib(target, b),
0b010 => Mnemonic::ADC_Ib(target, b),
0b011 => Mnemonic::SBB_Ib(target, b),
0b100 => Mnemonic::AND_Ib(target, b),
0b101 => Mnemonic::SUB_Ib(target, b),
0b110 => Mnemonic::XOR_Ib(target, b),
0b111 => Mnemonic::CMP_Ib(target, b),
_ => panic!("Illegal GPR1 mnemonic"),
},
OperandWidth::Word(w) => match reg {
0b000 => Mnemonic::ADD_Iv(target, ImmediateWord(w)),
0b001 => Mnemonic::OR_Iv(target, ImmediateWord(w)),
0b010 => Mnemonic::ADC_Iv(target, ImmediateWord(w)),
0b011 => Mnemonic::SBB_Iv(target, ImmediateWord(w)),
0b100 => Mnemonic::AND_Iv(target, ImmediateWord(w)),
0b101 => Mnemonic::SUB_Iv(target, ImmediateWord(w)),
0b110 => Mnemonic::XOR_Iv(target, ImmediateWord(w)),
0b111 => Mnemonic::CMP_Iv(target, ImmediateWord(w)),
ImmediateOperand::Word(w) => match reg {
0b000 => Mnemonic::ADD_Iv(target, w),
0b001 => Mnemonic::OR_Iv(target, w),
0b010 => Mnemonic::ADC_Iv(target, w),
0b011 => Mnemonic::SBB_Iv(target, w),
0b100 => Mnemonic::AND_Iv(target, w),
0b101 => Mnemonic::SUB_Iv(target, w),
0b110 => Mnemonic::XOR_Iv(target, w),
0b111 => Mnemonic::CMP_Iv(target, w),
_ => panic!("Illegal GPR1 mnemonic"),
},
}
@@ -256,8 +259,8 @@ impl Disassembler {
0x01 => modrmv!(self, ADD_FromReg),
0x02 => modrmb!(self, ADD_ToReg),
0x03 => modrmv!(self, ADD_ToReg),
0x04 => Mnemonic::ADD_ALIb(ImmediateByte(self.parse_byte())),
0x05 => Mnemonic::ADD_AXIv(ImmediateWord(self.parse_word())),
0x04 => Mnemonic::ADD_ALIb(self.parse_byte()),
0x05 => Mnemonic::ADD_AXIv(self.parse_word()),
0x06 => Mnemonic::PUSH_S(SegmentRegister::ES),
0x07 => Mnemonic::POP_S(SegmentRegister::ES),
@@ -266,8 +269,8 @@ impl Disassembler {
0x09 => modrmv!(self, OR_FromReg),
0x0A => modrmb!(self, OR_ToReg),
0x0B => modrmv!(self, OR_ToReg),
0x0C => Mnemonic::OR_ALIb(ImmediateByte(self.parse_byte())),
0x0D => Mnemonic::OR_AXIv(ImmediateWord(self.parse_word())),
0x0C => Mnemonic::OR_ALIb(self.parse_byte()),
0x0D => Mnemonic::OR_AXIv(self.parse_word()),
0x0E => Mnemonic::PUSH_S(SegmentRegister::CS),
0x0F => panic!("Opcode 0x0F (POP CS) is considered undefined"),
@@ -276,8 +279,8 @@ impl Disassembler {
0x11 => modrmv!(self, ADC_FromReg),
0x12 => modrmb!(self, ADC_ToReg),
0x13 => modrmv!(self, ADC_ToReg),
0x14 => Mnemonic::ADC_ALIb(ImmediateByte(self.parse_byte())),
0x15 => Mnemonic::ADC_AXIv(ImmediateWord(self.parse_word())),
0x14 => Mnemonic::ADC_ALIb(self.parse_byte()),
0x15 => Mnemonic::ADC_AXIv(self.parse_word()),
0x16 => Mnemonic::PUSH_S(SegmentRegister::SS),
0x17 => Mnemonic::POP_S(SegmentRegister::SS),
@@ -286,8 +289,8 @@ impl Disassembler {
0x19 => modrmv!(self, SBB_FromReg),
0x1A => modrmb!(self, SBB_ToReg),
0x1B => modrmv!(self, SBB_ToReg),
0x1C => Mnemonic::SBB_ALIb(ImmediateByte(self.parse_byte())),
0x1D => Mnemonic::SBB_AXIv(ImmediateWord(self.parse_word())),
0x1C => Mnemonic::SBB_ALIb(self.parse_byte()),
0x1D => Mnemonic::SBB_AXIv(self.parse_word()),
0x1E => Mnemonic::PUSH_S(SegmentRegister::DS),
0x1F => Mnemonic::POP_S(SegmentRegister::DS),
@@ -296,8 +299,8 @@ impl Disassembler {
0x21 => modrmv!(self, AND_FromReg),
0x22 => modrmb!(self, AND_ToReg),
0x23 => modrmv!(self, AND_ToReg),
0x24 => Mnemonic::AND_ALIb(ImmediateByte(self.parse_byte())),
0x25 => Mnemonic::AND_AXIv(ImmediateWord(self.parse_word())),
0x24 => Mnemonic::AND_ALIb(self.parse_byte()),
0x25 => Mnemonic::AND_AXIv(self.parse_word()),
0x26 => Mnemonic::OVERRIDE(SegmentRegister::ES),
0x27 => Mnemonic::DAA,
@@ -306,8 +309,8 @@ impl Disassembler {
0x29 => modrmv!(self, SUB_FromReg),
0x2A => modrmb!(self, SUB_ToReg),
0x2B => modrmv!(self, SUB_ToReg),
0x2C => Mnemonic::SUB_ALIb(ImmediateByte(self.parse_byte())),
0x2D => Mnemonic::SUB_AXIv(ImmediateWord(self.parse_word())),
0x2C => Mnemonic::SUB_ALIb(self.parse_byte()),
0x2D => Mnemonic::SUB_AXIv(self.parse_word()),
0x2E => Mnemonic::OVERRIDE(SegmentRegister::CS),
0x2F => Mnemonic::DAS,
@@ -316,8 +319,8 @@ impl Disassembler {
0x31 => modrmv!(self, XOR_FromReg),
0x32 => modrmb!(self, XOR_ToReg),
0x33 => modrmv!(self, XOR_ToReg),
0x34 => Mnemonic::XOR_ALIb(ImmediateByte(self.parse_byte())),
0x35 => Mnemonic::XOR_AXIv(ImmediateWord(self.parse_word())),
0x34 => Mnemonic::XOR_ALIb(self.parse_byte()),
0x35 => Mnemonic::XOR_AXIv(self.parse_word()),
0x36 => Mnemonic::OVERRIDE(SegmentRegister::SS),
0x37 => Mnemonic::AAA,
@@ -326,8 +329,8 @@ impl Disassembler {
0x39 => modrmv!(self, CMP_FromReg),
0x3A => modrmb!(self, CMP_ToReg),
0x3B => modrmv!(self, CMP_ToReg),
0x3C => Mnemonic::CMP_ALIb(ImmediateByte(self.parse_byte())),
0x3D => Mnemonic::CMP_AXIv(ImmediateWord(self.parse_word())),
0x3C => Mnemonic::CMP_ALIb(self.parse_byte()),
0x3D => Mnemonic::CMP_AXIv(self.parse_word()),
0x3E => Mnemonic::OVERRIDE(SegmentRegister::DS),
0x3F => Mnemonic::AAS,
@@ -370,22 +373,22 @@ impl Disassembler {
0x60..=0x6F => panic!("0x06 to 0x06F is considered undefined."),
0x70 => Mnemonic::JO(ImmediateByte(self.parse_byte())),
0x71 => Mnemonic::JNO(ImmediateByte(self.parse_byte())),
0x72 => Mnemonic::JB(ImmediateByte(self.parse_byte())),
0x73 => Mnemonic::JNB(ImmediateByte(self.parse_byte())),
0x74 => Mnemonic::JZ(ImmediateByte(self.parse_byte())),
0x75 => Mnemonic::JNZ(ImmediateByte(self.parse_byte())),
0x76 => Mnemonic::JBE(ImmediateByte(self.parse_byte())),
0x77 => Mnemonic::JA(ImmediateByte(self.parse_byte())),
0x78 => Mnemonic::JS(ImmediateByte(self.parse_byte())),
0x79 => Mnemonic::JNS(ImmediateByte(self.parse_byte())),
0x7A => Mnemonic::JPE(ImmediateByte(self.parse_byte())),
0x7B => Mnemonic::JPO(ImmediateByte(self.parse_byte())),
0x7C => Mnemonic::JL(ImmediateByte(self.parse_byte())),
0x7D => Mnemonic::JGE(ImmediateByte(self.parse_byte())),
0x7E => Mnemonic::JLE(ImmediateByte(self.parse_byte())),
0x7F => Mnemonic::JG(ImmediateByte(self.parse_byte())),
0x70 => Mnemonic::JO(self.parse_byte()),
0x71 => Mnemonic::JNO(self.parse_byte()),
0x72 => Mnemonic::JB(self.parse_byte()),
0x73 => Mnemonic::JNB(self.parse_byte()),
0x74 => Mnemonic::JZ(self.parse_byte()),
0x75 => Mnemonic::JNZ(self.parse_byte()),
0x76 => Mnemonic::JBE(self.parse_byte()),
0x77 => Mnemonic::JA(self.parse_byte()),
0x78 => Mnemonic::JS(self.parse_byte()),
0x79 => Mnemonic::JNS(self.parse_byte()),
0x7A => Mnemonic::JPE(self.parse_byte()),
0x7B => Mnemonic::JPO(self.parse_byte()),
0x7C => Mnemonic::JL(self.parse_byte()),
0x7D => Mnemonic::JGE(self.parse_byte()),
0x7E => Mnemonic::JLE(self.parse_byte()),
0x7F => Mnemonic::JG(self.parse_byte()),
0x80 => modrmgprb!(self),
0x81 => modrmgprv!(self),
@@ -407,9 +410,9 @@ impl Disassembler {
0x8D => modrmv!(self, LEA),
0xCD => Mnemonic::INT(ImmediateByte(self.parse_byte())),
0xCD => Mnemonic::INT(self.parse_byte()),
0xBB => Mnemonic::MOV_BXIv(ImmediateWord(self.parse_word())),
0xBB => Mnemonic::MOV_BXIv(self.parse_word()),
_ => {
eprintln!("Encountered unknown instruction '0x{:x}'", opcode);
eprintln!("Offset might be misaligned and data is being interpreted.");

18
src/disasm_macros.rs
View File

@@ -2,8 +2,8 @@
/// Generate a byte Opcode for 'normal' ModRM instructions with mem access and a reg
macro_rules! modrmb {
($self:ident, $variant:ident) => {{
let (target, reg) = $self.parse_modrm_byte(OperandWidth::Byte(0));
Mnemonic::$variant(target, Register::by_id(OperandWidth::Byte(reg)))
let (target, reg) = $self.parse_modrm_byte(ImmediateOperand::Byte(0));
Mnemonic::$variant(target, Register::by_id(ImmediateOperand::Byte(reg)))
}};
}
@@ -11,8 +11,8 @@ macro_rules! modrmb {
/// Generate a word Opcode for 'normal' ModRM instructions with mem access and a reg
macro_rules! modrmv {
($self:ident, $variant:ident) => {{
let (target, reg) = $self.parse_modrm_byte(OperandWidth::Word(0));
Mnemonic::$variant(target, Register::by_id(OperandWidth::Word(reg.into())))
let (target, reg) = $self.parse_modrm_byte(ImmediateOperand::Word(0));
Mnemonic::$variant(target, Register::by_id(ImmediateOperand::Word(reg.into())))
}};
}
@@ -20,7 +20,7 @@ macro_rules! modrmv {
/// Generate a word Opcode for 'normal' ModRM instructions with mem access and a segment reg
macro_rules! modrms {
($self:ident, $variant:ident) => {{
let (target, reg) = $self.parse_modrm_byte(OperandWidth::Word(0));
let (target, reg) = $self.parse_modrm_byte(ImmediateOperand::Word(0));
Mnemonic::$variant(target, SegmentRegister::by_id(reg))
}};
}
@@ -30,9 +30,9 @@ macro_rules! modrms {
/// GPR always has an imm value as second operand.
macro_rules! modrmgprb {
($self:ident) => {{
let (target, reg) = $self.parse_modrm_byte(OperandWidth::Byte(0));
let (target, reg) = $self.parse_modrm_byte(ImmediateOperand::Byte(0));
let imm = $self.parse_byte();
Self::modrm_reg_to_mnemonic(reg, target, OperandWidth::Byte(imm))
Self::modrm_reg_to_mnemonic(reg, target, ImmediateOperand::Byte(imm))
}};
}
@@ -41,8 +41,8 @@ macro_rules! modrmgprb {
/// GPR always has an imm value as second operand.
macro_rules! modrmgprv {
($self:ident) => {{
let (target, reg) = $self.parse_modrm_byte(OperandWidth::Word(0));
let (target, reg) = $self.parse_modrm_byte(ImmediateOperand::Word(0));
let imm = $self.parse_word();
Self::modrm_reg_to_mnemonic(reg, target, OperandWidth::Word(imm))
Self::modrm_reg_to_mnemonic(reg, target, ImmediateOperand::Word(imm))
}};
}

76
src/instructions.rs
View File

@@ -1,10 +1,24 @@
use core::fmt;
// b: 8, w: 16, v: 16 -> i just treat v and w the same, if nothing blows up
#[allow(non_camel_case_types)]
pub type b = u8;
#[allow(non_camel_case_types)]
pub type w = u16;
pub type ImmediateByte = u8;
pub type ImmediateWord = u16;
#[derive(Debug, Clone)]
#[allow(dead_code)]
/// Can be used to encode either byte or word operands
pub enum ImmediateOperand {
Byte(ImmediateByte),
Word(ImmediateWord),
}
impl fmt::Display for ImmediateOperand {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
Self::Byte(byte) => write!(f, "{}", byte),
Self::Word(word) => write!(f, "{}", word),
}
}
}
#[derive(Debug, Clone)]
#[allow(dead_code)]
@@ -204,9 +218,9 @@ pub type RegisterId = u8;
#[allow(dead_code)]
impl Register {
/// Find the register corresponding to the 8086 bytecode ID
pub fn by_id(id: OperandWidth) -> Self {
pub fn by_id(id: ImmediateOperand) -> Self {
match id {
OperandWidth::Byte(b) => match b {
ImmediateOperand::Byte(b) => match b {
0b000 => Self::AL,
0b001 => Self::CL,
0b010 => Self::DL,
@@ -217,7 +231,7 @@ impl Register {
0b111 => Self::BH,
_ => panic!("Invalid 8bit register ID encountered"),
},
OperandWidth::Word(w) => match w {
ImmediateOperand::Word(w) => match w {
0b000 => Self::AX,
0b001 => Self::CX,
0b010 => Self::DX,
@@ -290,33 +304,6 @@ impl fmt::Display for SegmentRegister {
}
}
/// An immediate byte value for an instruction.
#[derive(Debug, Clone)]
pub struct ImmediateByte(pub b);
/// An immediate word value for an instruction
#[derive(Debug, Clone)]
pub struct ImmediateWord(pub w);
macro_rules! impl_display_and_lowerhex {
($name:ident) => {
impl std::fmt::Display for $name {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(f, "{}", self.0)
}
}
impl std::fmt::LowerHex for $name {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
std::fmt::LowerHex::fmt(&self.0, f)
}
}
};
}
impl_display_and_lowerhex!(ImmediateByte);
impl_display_and_lowerhex!(ImmediateWord);
#[derive(Debug, Clone)]
/// ModRM byte can either target a memory location or some register
pub enum ModRmTarget {
@@ -339,7 +326,7 @@ impl std::fmt::Display for ModRmTarget {
pub struct MemoryIndex {
pub base: Option<Register>,
pub index: Option<Register>,
pub displacement: Option<OperandWidth>,
pub displacement: Option<ImmediateOperand>,
}
impl fmt::Display for MemoryIndex {
@@ -365,20 +352,3 @@ impl fmt::Display for MemoryIndex {
}
}
}
#[derive(Debug, Clone)]
#[allow(dead_code)]
/// Can be used to encode either byte or word operands
pub enum OperandWidth {
Byte(u8),
Word(u16),
}
impl fmt::Display for OperandWidth {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
Self::Byte(byte) => write!(f, "{}", byte),
Self::Word(word) => write!(f, "{}", word),
}
}
}