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-rw-r--r--src/armv7.rs1157
1 files changed, 1157 insertions, 0 deletions
diff --git a/src/armv7.rs b/src/armv7.rs
new file mode 100644
index 0000000..d65c8ae
--- /dev/null
+++ b/src/armv7.rs
@@ -0,0 +1,1157 @@
+use std::fmt::{Display, Formatter};
+
+use yaxpeax_arch::{Arch, Decodable, LengthedInstruction};
+
+impl Display for Opcode {
+ fn fmt(&self, f: &mut Formatter) -> Result<(), std::fmt::Error> {
+ match self {
+ Opcode::Incomplete(word) => { write!(f, "incomplete: {:#x}", word) },
+ Opcode::Invalid => { write!(f, "invalid") },
+ Opcode::POP => { write!(f, "pop") },
+ Opcode::B => { write!(f, "b") },
+ Opcode::BL => { write!(f, "bl") },
+ Opcode::BLX => { write!(f, "blx") },
+ Opcode::BX => { write!(f, "bx") },
+ Opcode::BXJ => { write!(f, "bxj") },
+ Opcode::AND => { write!(f, "and") },
+ Opcode::EOR => { write!(f, "eor") },
+ Opcode::SUB => { write!(f, "sub") },
+ Opcode::RSB => { write!(f, "rsb") },
+ Opcode::ADD => { write!(f, "add") },
+ Opcode::ADC => { write!(f, "adc") },
+ Opcode::SBC => { write!(f, "sbc") },
+ Opcode::RSC => { write!(f, "rsc") },
+ Opcode::TST => { write!(f, "tst") },
+ Opcode::TEQ => { write!(f, "teq") },
+ Opcode::CMP => { write!(f, "cmp") },
+ Opcode::CMN => { write!(f, "cmn") },
+ Opcode::ORR => { write!(f, "orr") },
+ Opcode::MOV => { write!(f, "mov") },
+ Opcode::BIC => { write!(f, "bic") },
+ Opcode::MVN => { write!(f, "mvn") },
+ Opcode::LSL => { write!(f, "lsl") },
+ Opcode::LSR => { write!(f, "lsr") },
+ Opcode::ASR => { write!(f, "asr") },
+ Opcode::RRX => { write!(f, "rrx") },
+ Opcode::ROR => { write!(f, "ror") },
+ Opcode::ADR => { write!(f, "adr") },
+ Opcode::LDREXH => { write!(f, "ldrexh") },
+ Opcode::STREXH => { write!(f, "strexh") },
+ Opcode::LDREXB => { write!(f, "ldrexb") },
+ Opcode::STREXB => { write!(f, "strexb") },
+ Opcode::LDREXD => { write!(f, "ldrexd") },
+ Opcode::STREXD => { write!(f, "strexd") },
+ Opcode::LDREX => { write!(f, "ldrex") },
+ Opcode::STREX => { write!(f, "strex") },
+ Opcode::LDM(false, false, _, _) => { write!(f, "ldmda") },
+ Opcode::LDM(false, true, _, _) => { write!(f, "ldmdb") },
+ Opcode::LDM(true, false, _, _) => { write!(f, "ldm") },
+ Opcode::LDM(true, true, _, _) => { write!(f, "ldmia") },
+ Opcode::STM(false, false, _, _) => { write!(f, "stmda") },
+ Opcode::STM(false, true, _, _) => { write!(f, "stmdb") },
+ Opcode::STM(true, false, _, _) => { write!(f, "stm") },
+ Opcode::STM(true, true, _, _) => { write!(f, "stmia") },
+ Opcode::LDR(_, _, _) => { write!(f, "ldr") },
+ Opcode::STR(_, _, _) => { write!(f, "str") },
+ Opcode::LDRB(_, _, _) => { write!(f, "ldrb") },
+ Opcode::STRB(_, _, _) => { write!(f, "strb") },
+ Opcode::LDRT(_) => { write!(f, "ldrt") },
+ Opcode::STRT(_) => { write!(f, "strt") },
+ Opcode::LDRBT(_) => { write!(f, "ldrbt") },
+ Opcode::STRBT(_) => { write!(f, "strbt") },
+ Opcode::SWP => { write!(f, "swp") },
+ Opcode::SWPB => { write!(f, "swpb") },
+ Opcode::MUL => { write!(f, "mul") },
+ Opcode::MLA => { write!(f, "mla") },
+ Opcode::UMAAL => { write!(f, "umaal") },
+ Opcode::MLS => { write!(f, "mls") },
+ Opcode::UMULL => { write!(f, "umull") },
+ Opcode::UMLAL => { write!(f, "umlal") },
+ Opcode::SMULL => { write!(f, "smull") },
+ Opcode::SMLAL => { write!(f, "smlal") }
+ }
+ }
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum Opcode {
+ Incomplete(u32),
+ Invalid,
+ POP,
+ B,
+ BL,
+ BLX,
+ BX,
+ BXJ,
+ AND,
+ EOR,
+ SUB,
+ RSB,
+ ADD,
+ ADC,
+ SBC,
+ RSC,
+ TST,
+ TEQ,
+ CMP,
+ CMN,
+ ORR,
+ MOV,
+ BIC,
+ MVN,
+ LSL,
+ LSR,
+ ASR,
+ RRX,
+ ROR,
+ ADR,
+ LDREXH,
+ STREXH,
+ LDREXB,
+ STREXB,
+ LDREXD,
+ STREXD,
+ LDREX,
+ STREX,
+ LDM(bool, bool, bool, bool),
+ STM(bool, bool, bool, bool),
+ LDR(bool, bool, bool),
+ STR(bool, bool, bool),
+ LDRB(bool, bool, bool),
+ STRB(bool, bool, bool),
+ LDRT(bool),
+ STRT(bool),
+ LDRBT(bool),
+ STRBT(bool),
+ SWP,
+ SWPB,
+ MUL,
+ MLA,
+ UMAAL,
+ MLS,
+ UMULL,
+ UMLAL,
+ SMULL,
+ SMLAL
+}
+
+static DATA_PROCESSING_OPCODES: [Opcode; 16] = [
+ Opcode::AND,
+ Opcode::EOR,
+ Opcode::SUB,
+ Opcode::RSB,
+ Opcode::ADD,
+ Opcode::ADC,
+ Opcode::SBC,
+ Opcode::RSC,
+ Opcode::TST,
+ Opcode::TEQ,
+ Opcode::CMP,
+ Opcode::CMN,
+ Opcode::ORR,
+ Opcode::MOV,
+ Opcode::BIC,
+ Opcode::MVN
+];
+
+#[derive(Debug, PartialEq, Eq, Copy, Clone)]
+pub enum ShiftSpec {
+ Immediate(u8),
+ Register(u8)
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum Operands {
+ RegisterList(u16),
+ TwoOperand(u8, u8),
+ RegImm(u8, u32),
+ RegRegList(u8, u16),
+ TwoRegImm(u8, u8, u32),
+ ThreeOperand(u8, u8, u8),
+ ThreeOperandImm(u8, u8, u16),
+ ThreeOperandWithShift(u8, u8, u8, ShiftSpec),
+ MulThreeRegs(u8, u8, u8),
+ MulFourRegs(u8, u8, u8, u8),
+ BranchOffset(i32)
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct Instruction {
+ pub condition: ConditionCode,
+ pub opcode: Opcode,
+ pub operands: Operands,
+ pub s: bool
+}
+
+impl Instruction {
+ pub fn blank() -> Instruction {
+ Instruction {
+ condition: ConditionCode::AL,
+ opcode: Opcode::Invalid,
+ operands: Operands::BranchOffset(0),
+ s: false
+ }
+ }
+ pub fn set_S(&mut self, value: bool) {
+ self.s = value;
+ }
+ pub fn S(&self) -> bool { self.s }
+}
+
+impl Display for Instruction {
+ fn fmt(&self, f: &mut Formatter) -> Result<(), std::fmt::Error> {
+ fn format_reg_list(f: &mut Formatter, mut list: u16) -> Result<(), std::fmt::Error> {
+ write!(f, "{{");
+ let mut i = 0;
+ let mut tail = false;
+ while i < 16 {
+ let present = (list & 1) == 1;
+ if present {
+ if tail {
+ write!(f, ", ")?;
+ } else {
+ tail = true;
+ }
+ write!(f, "{}", reg_name(i));
+ }
+ i += 1;
+ list >>= 1;
+ }
+ write!(f, "}}")
+ }
+
+ fn format_shift(f: &mut Formatter, Rm: u8, shift: ShiftSpec) -> Result<(), std::fmt::Error> {
+ fn shift_tpe_to_str(tpe: u8) -> &'static str {
+ match tpe {
+ 0b00 => "lsl",
+ 0b01 => "lsr",
+ 0b10 => "asr",
+ 0b11 => "ror",
+ _ => { unreachable!(); }
+ }
+ }
+ match shift {
+ ShiftSpec::Immediate(0) => {
+ write!(f, "{}", reg_name(Rm))
+ },
+ ShiftSpec::Immediate(v) => {
+ let tpe = v & 0x3;
+ let imm = v >> 2;
+ write!(f, "{}, {} {}", reg_name(Rm), shift_tpe_to_str(tpe), imm)
+ },
+ ShiftSpec::Register(v) => {
+ let tpe = v & 0x3;
+ let Rs = v >> 2;
+ write!(f, "{}, {} {}", reg_name(Rm), shift_tpe_to_str(tpe), reg_name(Rs))
+ },
+ }
+ }
+
+ fn format_reg_shift_mem(f: &mut Formatter, Rd: u8, Rm: u8, shift: ShiftSpec, add: bool, pre: bool, wback: bool) -> Result<(), std::fmt::Error> {
+ let op = if add { "" } else { "-" };
+
+ match (pre, wback) {
+ (true, true) => {
+ write!(f, "[{}, {}", reg_name(Rd), op)?;
+ format_shift(f, Rm, shift)?;
+ write!(f, "]!")
+ },
+ (true, false) => {
+ write!(f, "[{}, {}", reg_name(Rd), op)?;
+ format_shift(f, Rm, shift)?;
+ write!(f, "]")
+ },
+ (false, true) => {
+ unreachable!("I don't know how to render an operand with pre==false and wback==true, this seems like it should be LDRT");
+ },
+ (false, false) => {
+ write!(f, "[{}], {}", reg_name(Rd), op)?;
+ format_shift(f, Rm, shift)
+ }
+ }
+ }
+
+ fn format_reg_imm_mem(f: &mut Formatter, Rn: u8, imm: u32, add: bool, pre: bool, wback: bool) -> Result<(), std::fmt::Error> {
+ if imm != 0 {
+ let op = if add { "" } else { "-" };
+
+ match (pre, wback) {
+ (true, true) => {
+ write!(f, "[{}, #{}{:#x}]!", reg_name(Rn), op, imm * 4)
+ },
+ (true, false) => {
+ write!(f, "[{}, #{}{:#x}]", reg_name(Rn), op, imm * 4)
+ },
+ (false, true) => {
+ unreachable!("I don't know how to render an operand with pre==false and wback==true, this seems like it should be LDRT");
+ },
+ (false, false) => {
+ write!(f, "[{}], #{}{:#x}", reg_name(Rn), op, imm * 4)
+ }
+ }
+ } else {
+ match (pre, wback) {
+ (true, true) => {
+ write!(f, "[{}]!", reg_name(Rn))
+ },
+ (true, false) => {
+ write!(f, "[{}]", reg_name(Rn))
+ },
+ (false, true) => {
+ unreachable!("I don't know how to render an operand with pre==false and wback==true, this seems like it should be LDRT");
+ },
+ (false, false) => {
+ write!(f, "[{}]", reg_name(Rn))
+ }
+ }
+ }
+ }
+ fn reg_name(num: u8) -> &'static str {
+ match num {
+ 0 => "r0",
+ 1 => "r1",
+ 2 => "r2",
+ 3 => "r3",
+ 4 => "r4",
+ 5 => "r5",
+ 6 => "r6",
+ 7 => "r7",
+ 8 => "r8",
+ 9 => "sb",
+ 10 => "r10",
+ 11 => "fp",
+ 12 => "ip",
+ 13 => "sp",
+ 14 => "lr",
+ 15 => "pc",
+ _ => { unreachable!(); }
+ }
+ }
+ match self.opcode {
+ Opcode::LDR(true, false, false) => {
+ match self.operands {
+ Operands::TwoRegImm(13, Rt, 4) => {
+ return write!(f, "pop{} {{{}}}", self.condition, reg_name(Rt));
+ },
+ _ => {}
+ }
+ },
+ Opcode::STR(false, true, true) => {
+ match self.operands {
+ Operands::TwoRegImm(13, Rt, 4) => {
+ return write!(f, "push{} {{{}}}", self.condition, reg_name(Rt));
+ },
+ _ => {}
+ }
+ },
+ Opcode::LDM(true, false, true, _usermode) => {
+ // TODO: what indicates usermode in the ARM syntax?
+ match self.operands {
+ Operands::RegRegList(13, list) => {
+ write!(f, "pop{} ", self.condition)?;
+ return format_reg_list(f, list);
+ }
+ _ => {}
+ }
+ }
+ Opcode::STM(false, true, true, _usermode) => {
+ // TODO: what indicates usermode in the ARM syntax?
+ match self.operands {
+ Operands::RegRegList(13, list) => {
+ write!(f, "push{} ", self.condition)?;
+ return format_reg_list(f, list);
+ }
+ _ => {}
+ }
+ }
+ _ => {}
+ }
+
+ match self.opcode {
+ Opcode::LDR(add, pre, wback) |
+ Opcode::STR(add, pre, wback) |
+ Opcode::STRB(add, pre, wback) |
+ Opcode::LDRB(add, pre, wback) => {
+ match self.operands {
+ Operands::TwoRegImm(Rn, Rt, imm) => {
+ write!(
+ f, "{}{} {}, ",
+ self.opcode,
+ self.condition,
+ reg_name(Rt),
+ )?;
+ return format_reg_imm_mem(f, Rn, imm, add, pre, wback);
+ }
+ // TODO: this might not be necessary
+ Operands::RegImm(Rt, imm) => {
+ write!(
+ f, "{}{} {}, ",
+ self.opcode,
+ self.condition,
+ reg_name(Rt)
+ )?;
+ return format_reg_imm_mem(f, 15, imm, add, pre, wback);
+ },
+ Operands::ThreeOperandWithShift(Rd, Rn, Rm, shift) => {
+ write!(
+ f, "{}{} {}, ",
+ self.opcode,
+ self.condition,
+ reg_name(Rn)
+ )?;
+ return format_reg_shift_mem(f, Rd, Rm, shift, add, pre, wback);
+ }
+ _ => { unreachable!(); }
+ }
+ }
+ Opcode::STM(add, pre, wback, usermode) |
+ Opcode::LDM(add, pre, wback, usermode) => {
+ match self.operands {
+ Operands::RegRegList(Rr, list) => {
+ write!(
+ f, "{}{} {}{}, ",
+ self.opcode,
+ self.condition,
+ reg_name(Rr),
+ if wback { "!" } else { "" }
+ )?;
+ return format_reg_list(f, list);
+ },
+ _ => { unreachable!(); }
+ }
+ },
+ Opcode::Incomplete(word) => {
+ write!(f, "incomplete: {:#x}", word)
+ },
+ _ => {
+ write!(f, "{}{}", self.opcode, self.condition)?;
+ match self.operands {
+ Operands::RegisterList(list) => {
+ write!(f, " ")?;
+ format_reg_list(f, list)?;
+ },
+ Operands::TwoOperand(a, b) => {
+ write!(f, " {}, {}", reg_name(a), reg_name(b))?;
+ },
+ Operands::RegImm(a, imm) => {
+ write!(f, " {}, {:#x}", reg_name(a), imm * 4)?;
+ },
+ Operands::RegRegList(r, list) => {
+ write!(f, " {}, ", reg_name(r))?;
+ format_reg_list(f, list)?;
+ },
+ Operands::TwoRegImm(a, b, imm) => {
+ write!(f, " <unimplemented>")?;
+ },
+ Operands::ThreeOperand(a, b, c) => {
+ write!(f, " {}, {}, {}", reg_name(a), reg_name(b), reg_name(c))?;
+ },
+ Operands::ThreeOperandImm(a, b, imm) => {
+ write!(f, " <unimplemented>")?;
+ },
+ Operands::ThreeOperandWithShift(a, b, c, shift) => {
+ write!(f, " {}, {}, ", reg_name(a), reg_name(b))?;
+ format_shift(f, c, shift)?;
+ },
+ Operands::MulThreeRegs(a, b, c) => {
+ write!(f, " {}, {}, {}", reg_name(a), reg_name(b), reg_name(c))?;
+ },
+ Operands::MulFourRegs(a, b, c, d) => {
+ write!(f, " <unimplemented>")?;
+ },
+ Operands::BranchOffset(imm) => {
+ if imm < 0 {
+ write!(f, " $-{:#x}", (-imm) * 4)?;
+ } else {
+ write!(f, " $+{:#x}", imm * 4)?;
+ }
+ }
+ };
+ Ok(())
+ }
+ }
+ }
+}
+
+impl LengthedInstruction for Instruction {
+ type Unit = <ARMv7 as Arch>::Address;
+ fn min_size() -> Self::Unit {
+ 4
+ }
+ fn len(&self) -> Self::Unit {
+ 4
+ }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum ConditionCode {
+ EQ,
+ NE,
+ HS,
+ LO,
+ MI,
+ PL,
+ VS,
+ VC,
+ HI,
+ LS,
+ GE,
+ LT,
+ GT,
+ LE,
+ AL
+}
+
+impl Display for ConditionCode {
+ fn fmt(&self, f: &mut Formatter) -> Result<(), std::fmt::Error> {
+ match self {
+ ConditionCode::EQ => write!(f, "eq"),
+ ConditionCode::NE => write!(f, "ne"),
+ ConditionCode::HS => write!(f, "hs"),
+ ConditionCode::LO => write!(f, "lo"),
+ ConditionCode::MI => write!(f, "mi"),
+ ConditionCode::PL => write!(f, "pl"),
+ ConditionCode::VS => write!(f, "vs"),
+ ConditionCode::VC => write!(f, "vc"),
+ ConditionCode::HI => write!(f, "hi"),
+ ConditionCode::LS => write!(f, "ls"),
+ ConditionCode::GE => write!(f, "ge"),
+ ConditionCode::LT => write!(f, "lt"),
+ ConditionCode::GT => write!(f, "gt"),
+ ConditionCode::LE => write!(f, "le"),
+ ConditionCode::AL => Ok(())
+ }
+ }
+}
+
+impl ConditionCode {
+ pub fn build(value: u8) -> ConditionCode {
+ match value {
+ 0b0000 => ConditionCode::EQ,
+ 0b0001 => ConditionCode::NE,
+ 0b0010 => ConditionCode::HS,
+ 0b0011 => ConditionCode::LO,
+ 0b0100 => ConditionCode::MI,
+ 0b0101 => ConditionCode::PL,
+ 0b0110 => ConditionCode::VS,
+ 0b0111 => ConditionCode::VC,
+ 0b1000 => ConditionCode::HI,
+ 0b1001 => ConditionCode::LS,
+ 0b1010 => ConditionCode::GE,
+ 0b1011 => ConditionCode::LT,
+ 0b1100 => ConditionCode::GT,
+ 0b1101 => ConditionCode::LE,
+ 0b1110 => ConditionCode::AL,
+ _ => unsafe {
+ // this means the argument `value` must never be outside [0,15]
+ // which itself means this function shouldn't be public
+ unreachable!();
+ }
+ }
+ }
+}
+
+impl Decodable for Instruction {
+ fn decode<'a, T: IntoIterator<Item=&'a u8>>(bytes: T) -> Option<Self> {
+ let mut blank = Instruction::blank();
+ match blank.decode_into(bytes) {
+ Some(_) => Some(blank),
+ None => None
+ }
+ }
+ fn decode_into<'a, T: IntoIterator<Item=&'a u8>>(&mut self, bytes: T) -> Option<()> {
+ fn read_word<'a, T: IntoIterator<Item=&'a u8>>(bytes: T) -> Option<u32> {
+ let mut iter = bytes.into_iter();
+ let instr: u32 =
+ ((*iter.next()? as u32) ) |
+ ((*iter.next()? as u32) << 8 ) |
+ ((*iter.next()? as u32) << 16) |
+ ((*iter.next()? as u32) << 24);
+
+ Some(instr)
+ }
+
+ let word = match read_word(bytes) {
+ Some(word) => word,
+ None => { return None; }
+ };
+
+ let (cond, opc_upper) = {
+ let top_byte = word >> 24;
+ (
+ ((top_byte >> 4) & 0xf) as u8,
+ ((top_byte >> 1) & 0x7) as u8
+ )
+ };
+
+ if cond == 0b1111 {
+ // do unconditional instruction stuff
+ self.condition = ConditionCode::AL;
+ self.opcode = Opcode::Incomplete(word);
+ return Some(());
+ } else {
+ self.condition = ConditionCode::build(cond);
+ }
+
+ // distinction at this point is on page A5-192
+ match opc_upper {
+ 0b000 => {
+ // the instruction looks like
+ // |c o n d|0 0 0|x x x x|x|x x x x|x x x x|x x x x x|x x|x|x x x x|
+ let (s, opcode) = {
+ let part = word >> 20;
+ (
+ (part & 0x01) == 1,
+ ((part >> 1) & 0x0f) as u8
+ )
+ };
+
+ if (word & 0b10010000) == 0b10010000 {
+ // the instruction looks like
+ // |c o n d|0 0 0|x x x x|x|x x x x|x x x x|x x x x 1|x x|1|x x x x|
+ // which is a category of multiplies and extra load/store
+ if (word & 0x0f0000f0) == 0x00000090 {
+ // |c o n d|0 0 0 0|x x x x x x x x x x x x x x x x|1 0 0 1|x x x x|
+ // Multiply instruction extension space
+ // (page A5-200)
+ let op = ((word >> 20) & 0x0f) as u8;
+ let s = (op & 1) == 1;
+ let op = op >> 1;
+ let R = [
+ (word & 0x0f) as u8,
+ ((word >> 8) & 0x0f) as u8,
+ ((word >> 12) & 0x0f) as u8,
+ ((word >> 16) & 0x0f) as u8
+ ];
+ self.set_S(s);
+ match op {
+ 0b000 => {
+ self.opcode = Opcode::MUL;
+ self.operands = Operands::MulThreeRegs(R[3], R[0], R[1]);
+ },
+ 0b001 => {
+ self.opcode = Opcode::MLA;
+ self.operands = Operands::MulFourRegs(R[3], R[0], R[1], R[2]);
+ },
+ 0b010 => {
+ if s {
+ self.opcode = Opcode::Invalid;
+ return None;
+ }
+ self.opcode = Opcode::UMAAL;
+ self.operands = Operands::MulFourRegs(R[2], R[3], R[0], R[1]);
+ },
+ 0b011 => {
+ if s {
+ self.opcode = Opcode::Invalid;
+ return None;
+ }
+ self.opcode = Opcode::MLS;
+ self.operands = Operands::MulFourRegs(R[3], R[0], R[1], R[2]);
+ }
+ 0b100 => {
+ self.opcode = Opcode::UMULL;
+ self.operands = Operands::MulFourRegs(R[2], R[3], R[0], R[1]);
+ }
+ 0b101 => {
+ self.opcode = Opcode::UMLAL;
+ self.operands = Operands::MulFourRegs(R[2], R[3], R[0], R[1]);
+ }
+ 0b110 => {
+ self.opcode = Opcode::SMULL;
+ self.operands = Operands::MulFourRegs(R[2], R[3], R[0], R[1]);
+ }
+ 0b111 => {
+ self.opcode = Opcode::SMLAL;
+ self.operands = Operands::MulFourRegs(R[2], R[3], R[0], R[1]);
+ }
+ _ => { unreachable!(format!("mul upcode: {:x}", op)) }
+ }
+ } else {
+ // |c o n d|0 0 0 u|x x x x x x x x x x x x x x x x|1 u u 1|x x x x|
+ // with at least one of u being 1
+ // misc instructions
+ let (flags, Rn, Rd, HiOffset, op, LoOffset) = {
+ let LoOffset = (word & 0x0f) as u8;
+ let word = word >> 5;
+ let op = (word & 0x3) as u8;
+ let word = word >> 3;
+ let HiOffset = (word & 0x0f) as u8;
+ let word = word >> 4;
+ let Rd = (word & 0x0f) as u8;
+ let word = word >> 4;
+ let Rn = (word & 0x0f) as u8;
+ let word = word >> 4;
+ let flags = (word & 0x1f) as u8;
+ (flags, Rn, Rd, HiOffset, op, LoOffset)
+ };
+ println!("{:032b}", word);
+ println!(" {:05b}|{:04b}|{:04b}|{:04b}|1{:02b}1|{:04b}", flags, Rn, Rd, HiOffset, op, LoOffset);
+ match op {
+ 0x00 => {
+ // |c o n d|0 0 0 1|x x x x x x x x x x x x x x x x|1 0 0 1|x x x x|
+ // this is swp or {ld,st}ex, conditional on bit 23
+ match flags {
+ 0b10000 => {
+ self.opcode = Opcode::SWP;
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ },
+ 0b10001 | 0b10010 | 0b10011 => {
+ self.opcode = Opcode::Invalid;
+ return None;
+ }
+ 0b10100 => {
+ self.opcode = Opcode::SWPB;
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ },
+ 0b10101 | 0b10110 | 0b10111 => {
+ self.opcode = Opcode::Invalid;
+ return None;
+ }
+ 0b11000 => {
+ self.opcode = Opcode::STREX;
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ }
+ 0b11001 => {
+ self.opcode = Opcode::LDREX;
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ }
+ 0b11010 => {
+ self.opcode = Opcode::STREXD;
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ }
+ 0b11011 => {
+ self.opcode = Opcode::LDREXD;
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ }
+ 0b11100 => {
+ self.opcode = Opcode::STREXB;
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ }
+ 0b11101 => {
+ self.opcode = Opcode::LDREXB;
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ }
+ 0b11110 => {
+ self.opcode = Opcode::STREXH;
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ }
+ 0b11111 => {
+ self.opcode = Opcode::LDREXH;
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ }
+ _ => {
+ /*
+ * This is unreachable because we have checked op is b1001,
+ * meaning the high bit of flags *MUST* be 1.
+ *
+ * high bit and mid-bits of op all being 0 was checked
+ * before reaching here.
+ */
+ unreachable!(format!("load/store flags: {:x}", flags));
+ }
+ }
+ }
+ 0x01 => {
+ // |c o n d|0 0 0 x|x x x x x x x x x x x x x x x x|1 0 1 1|x x x x|
+ // page A5-201
+ self.opcode = Opcode::Incomplete(word);
+ return Some(());
+ match flags {
+ 0b00010 => {
+ // self.opcode = Opcode::STRHT_sub;
+ self.opcode = Opcode::Incomplete(word);
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ }
+ 0b01010 => {
+ // self.opcode = Opcode::STRHT_add;
+ self.opcode = Opcode::Incomplete(word);
+ self.operands = Operands::ThreeOperand(Rn, Rd, LoOffset);
+ }
+ 0b00110 => {
+ // self.opcode = Opcode::STRHT_sub;
+ self.opcode = Opcode::Incomplete(word);
+ let imm = ((HiOffset << 4) as u16 | LoOffset as u16);
+ self.operands = Operands::ThreeOperandImm(Rn, Rd, imm);
+ }
+ 0b01110 => {
+ // self.opcode = Opcode::STRHT_add;
+ self.opcode = Opcode::Incomplete(word);
+ let imm = ((HiOffset << 4) as u16 | LoOffset as u16);
+ self.operands = Operands::ThreeOperandImm(Rn, Rd, imm);
+ }
+ _ => {
+ unreachable!();
+ }
+ }
+ }
+ 0x10 => {
+ // |c o n d|0 0 0 x|x x x x x x x x x x x x x x x x|1 1 0 1|x x x x|
+ // page A5-201
+ self.opcode = Opcode::Incomplete(word);
+ return Some(());
+ }
+ 0x11 => {
+ // |c o n d|0 0 0 x|x x x x x x x x x x x x x x x x|1 1 1 1|x x x x|
+ // page A5-201
+ self.opcode = Opcode::Incomplete(word);
+ return Some(());
+ }
+ _ => { unreachable!(); }
+ }
+ }
+ } else {
+ // we know this is data processing with imm or reg shift, OR
+ // misc instructions in Figure A3-4
+
+ if s == false && opcode >= 0b1000 && opcode < 0b1100 {
+ // the instruction looks like
+ // |c o n d|0 0 0|1 0 x x|0|x x x x|x x x x|x x x x x|x x|x|x x x x|
+ // misc instructions (page A5-194)
+ self.opcode = Opcode::Incomplete(word);
+ return Some(());
+ } else {
+ if opcode >= 16 {
+ unreachable!();
+ }
+ self.opcode = DATA_PROCESSING_OPCODES[opcode as usize];
+ self.set_S(s);
+
+ // at this point we know this is a data processing instruction
+ // either immediate shift or register shift
+ if word & 0b00010000 == 0 {
+ // |c o n d|0 0 0|1 0 x x|0|x x x x|x x x x|x x x x x|x x|0|x x x x|
+ // interpret the operands as
+ // | Rn | Rd | shift amount | shift | 0 | Rm |
+ let (Rn, Rd, shift_spec, Rm) = {
+ let Rm = (word & 0x0f) as u8;
+ let word = word >> 5;
+ let shift_spec = (word & 0x7f) as u8;
+ let word = word >> 7;
+ let Rd = (word & 0x0f) as u8;
+ let Rn = ((word >> 4) & 0x0f) as u8;
+ (Rn, Rd, shift_spec, Rm)
+ };
+
+ if shift_spec == 0 {
+ if (0b1101 & opcode) == 0b1101 {
+ // MOV or MVN
+ self.operands = Operands::TwoOperand(Rd, Rm);
+ } else {
+ self.operands = Operands::ThreeOperand(Rd, Rn, Rm);
+ }
+ } else {
+ /*
+ * TODO: look at how this interacts with mov and mvn
+ */
+ self.operands = Operands::ThreeOperandWithShift(Rd, Rn, Rm, ShiftSpec::Immediate(shift_spec));
+ }
+ } else {
+ // known 0 because it and bit 5 are not both 1 --v
+ // |c o n d|0 0 0|1 0 x x|0|x x x x|x x x x|x x x x 0|x x|1|x x x x|
+ // interpret the operands as
+ // | Rn | Rd | Rs | 0 | shift | 1 | Rm |
+ let (Rn, Rd, shift_spec, Rm) = {
+ let Rm = (word & 0x0f) as u8;
+ let word = word >> 5;
+ let shift_spec = (word & 0x7f) as u8;
+ let word = word >> 7;
+ let Rd = (word & 0x0f) as u8;
+ let Rn = ((word >> 4) & 0x0f) as u8;
+ (Rn, Rd, shift_spec, Rm)
+ };
+ // page A5-200 indicates that saturating add and subtract should be
+ // here?
+ if (0b1101 & opcode) == 0b1101 {
+ // these are all invalid
+ self.opcode = Opcode::Invalid;
+ return None;
+ } else {
+ self.operands = Operands::ThreeOperandWithShift(Rd, Rn, Rm, ShiftSpec::Register(shift_spec));
+ }
+ }
+ }
+ }
+ },
+ 0b001 => {
+ // the instruction looks like
+ // |c o n d|0 0 1|x x x x|x|x x x x|x x x x|x x x x x|x x|x|x x x x|
+ // bottom part of table A5-2 on page A5-194
+ let (s, opcode) = {
+ let part = word >> 20;
+ (
+ (part & 0x01) == 1,
+ ((part >> 1) & 0x0f) as u8
+ )
+ };
+ if s == false && opcode >= 0b1000 && opcode < 0b1100 {
+ // the instruction looks like
+ // |c o n d|0 0 0|1 0 x x|0|x x x x|x x x x|x x x x x|x x|x|x x x x|
+ // misc instructions (page A5-194)
+ self.opcode = Opcode::Incomplete(word);
+ return Some(());
+ } else {
+ if opcode >= 16 {
+ unreachable!();
+ }
+ self.opcode = DATA_PROCESSING_OPCODES[opcode as usize];
+ self.set_S(s);
+
+ let (Rn, imm) = {
+ let imm = word & 0x0000ffff;
+ let word = word >> 16;
+ ((word & 0x0f) as u8, imm)
+ };
+ if (opcode == 0b0010 || opcode == 0b0100) && Rn == 0b1111 {
+ self.opcode = Opcode::ADR;
+ }
+ match opcode {
+ 0b1101 => {
+ self.operands = Operands::RegImm(
+ ((word >> 12) & 0xf) as u8,
+ (word & 0x0fff) as u32
+ );
+ }
+ _ => {
+ self.operands = Operands::RegImm(Rn, imm);
+ }
+ }
+
+ }
+ /* ... */
+ }
+ 0b010 => {
+ let Rn = ((word >> 16) & 0x0f) as u8;
+ let op = ((word >> 20) & 0x1f) as u8;
+ let add = (op & 0b01000) != 0;
+ let (imm, Rt) = {
+ ((word & 0x0fff) as u16, ((word >> 12) & 0x0f) as u8)
+ };
+ if (op & 0b10010) == 0b00010 {
+ let op = op & 0b00111;
+ // |c o n d|0 1 0|0 x x 1 x|x x x x x x x x x x x x x x x|x|x x x x|
+ /*
+ 0x010 -> STRT
+ 0x011 -> LDRT
+ 0x110 -> STRBT
+ 0x111 -> LDRBT
+ */
+ self.opcode = match op {
+ 0b010 => Opcode::STRT(add),
+ 0b011 => Opcode::LDRT(add),
+ 0b110 => Opcode::STRBT(add),
+ 0b111 => Opcode::LDRBT(add),
+ _ => { unreachable!(); }
+ };
+ } else {
+ /*
+ xx0x0 not 0x010 -> STR (imm)
+ xx0x1 not 0x011 -> LDR (imm)
+ xx1x0 not 0x110 -> STRB (imm)
+ xx1x1 not 0x111 -> LDRB (imm)
+ */
+ let pre = (op & 0b10000) != 0;
+ let wback = (op & 0b00010) != 0;
+ let op = op & 0b00101;
+ self.opcode = match op {
+ 0b000 => Opcode::STR(add, pre, wback),
+ 0b001 => {
+ if Rn == 0b1111 {
+ self.operands = Operands::RegImm(Rt, imm.into());
+ self.opcode = Opcode::LDR(add, pre, wback);
+ return Some(());
+ }
+ Opcode::LDR(add, pre, wback)
+ },
+ 0b100 => Opcode::STRB(add, pre, wback),
+ 0b101 => {
+ if Rn == 0b1111 {
+ self.operands = Operands::RegImm(Rt, imm.into());
+ self.opcode = Opcode::LDRB(add, pre, wback);
+ return Some(());
+ }
+ Opcode::LDRB(add, pre, wback)
+ },
+ _ => { unreachable!(); }
+ };
+ }
+ self.operands = Operands::TwoRegImm(Rn, Rt, imm.into());
+ },
+ 0b011 => {
+ // page A5-192 to distinguish the following:
+ // check for media instructions, and if not, load/store word and unsigned byte
+ if (word & 0x00000010) != 0 {
+ // |c o n d|0 1 1|x x x x|x|x x x x|x x x x|x x x x x|x x|1|x x x x|
+ // using language from A5-206: A == 1 and B == 1
+ // so this is media instructions (A5-207)
+ } else {
+ // |c o n d|0 1 1|x x x x|x|x x x x|x x x x|x x x x x|x x|0|x x x x|
+ // instructions here are A == 1, B == 0 in A5-206
+ let op = ((word >> 20) & 0x1f) as u8;
+
+ let add = (op & 0b01000) != 0;
+ /*
+ xx0x0 not 0x010 -> STR (register)
+ 0x010 -> STRT
+ xx0x1 not 0x011 -> LDR (register)
+ 0x011 -> LDRT
+ xx1x0 not 0x110 -> STRB (register)
+ 0x110 -> STRBT
+ xx1x1 not 0x111 -> LDRB (register)
+ 0x111 -> LDRBT
+ */
+ let Rn = ((word >> 16) & 0x0f) as u8;
+ if (op & 0b10010) == 0b00010 {
+ let op = op & 0b00111;
+ // |c o n d|0 1 1|0 x x 1 x|x x x x x x x x x x x x x x x|0|x x x x|
+ /*
+ 0x010 -> STRT
+ 0x011 -> LDRT
+ 0x110 -> STRBT
+ 0x111 -> LDRBT
+ */
+ self.opcode = match op {
+ 0b010 => Opcode::STRT(add),
+ 0b011 => Opcode::LDRT(add),
+ 0b110 => Opcode::STRBT(add),
+ 0b111 => Opcode::LDRBT(add),
+ _ => { unreachable!(); }
+ };
+ } else {
+ /*
+ xx0x0 not 0x010 -> STR (imm)
+ xx0x1 not 0x011 -> LDR (imm)
+ xx1x0 not 0x110 -> STRB (imm)
+ xx1x1 not 0x111 -> LDRB (imm)
+ */
+ let pre = (op & 0b10000) != 0;
+ let wback = (op & 0b00010) != 0;
+ let op = op & 0b00101;
+ self.opcode = match op {
+ 0b000 => Opcode::STR(add, pre, wback),
+ 0b001 => Opcode::LDR(add, pre, wback),
+ 0b100 => Opcode::STRB(add, pre, wback),
+ 0b101 => Opcode::LDRB(add, pre, wback),
+ _ => { unreachable!(); }
+ };
+ }
+ let (Rt, Rm, shift) = {
+ let Rm = (word & 0xf) as u8;
+ let word = word >> 5;
+ let shift = (word & 0x7f) as u8;
+ let word = word >> 7;
+ let Rt = (word & 0xf) as u8;
+ (Rt, Rm, shift)
+ };
+ self.operands = Operands::ThreeOperandWithShift(Rn, Rt, Rm, ShiftSpec::Immediate(shift));
+ }
+ return Some(());
+ },
+ 0b100 | 0b101 => {
+ // branch, branch with link, and block data transfer
+ // page A5-212
+ let op = (word >> 20) & 0x3f;
+ if op < 0b100000 {
+ let wback = (op & 0b000010) != 0;
+ let add = (op & 0b001000) != 0;
+ let pre = (op & 0b010000) != 0;
+ let usermode = (op & 0b000100) != 0;
+ self.opcode = if (op & 1) == 0 {
+ Opcode::STM(add, pre, wback, usermode)
+ } else {
+ Opcode::LDM(add, pre, wback, usermode)
+ };
+ self.operands = Operands::RegRegList(
+ ((word >> 16) & 0xf) as u8,
+ (word & 0xffff) as u16
+ );
+ } else if op < 0b110000 {
+ // 10xxxx
+ // the + 1 is to compensate for an architecturally-defined initial offset
+ self.opcode = Opcode::B;
+ self.operands = Operands::BranchOffset(((word & 0x00ffff) + 1) as i16 as i32);
+ } else {
+ // 11xxxx
+ // the + 1 is to compensate for an architecturally-defined initial offset
+ self.opcode = Opcode::BL;
+ self.operands = Operands::BranchOffset(((word & 0x00ffff) + 1) as i16 as i32);
+ }
+ },
+ 0b110 | 0b111 => {
+ // coprocessor instructions and supervisor call
+ // page A5-213
+ self.opcode = Opcode::Incomplete(word);
+ return Some(());
+ },
+ _ => { unreachable!(); }
+ }
+ Some(())
+ }
+}
+
+pub struct ARMv7;
+impl Arch for ARMv7 {
+ type Address = u32;
+ type Instruction = Instruction;
+ type Operand = Operands;
+}
+
+
+/*
+ * tests: (armv7?)
+ * [0x00, 0x00, 0x90, 0xe0]
+ * adds r0, r0, r0
+ *
+ * [0x00, 0x00, 0x82, 0xe0]
+ * add r0, r2, r0
+ *
+ * [0x00, 0x00, 0x88, 0xe0]
+ * add r0, r8, r0
+ *
+ * [0x00, 0x01, 0x80, 0xe0]
+ * add r0, r0, r0, lsl 2
+ *
+ * [0x00, 0x80, 0x00, 0x00]
+ * andeq r8, r0, r0
+ *
+ * [0xc0, 0x80, 0x20, 0x00]
+ * eoreq r8, r0, r0, asr 1
+ *
+ * [0x00, 0x00, 0xa2, 0xe1]
+ * mov r0, r0
+ *
+ * [0x00, 0x00, 0xaf, 0xe1]
+ * mov r0, r0
+ *
+ * [0x10, 0x00, 0xaf, 0xe1]
+ * invalid
+ *
+ * [0x01, 0x00, 0xaf, 0xe1]
+ * mov r0, r1
+ *
+ * [0x00, 0x01, 0xaf, 0xe1]
+ * invalid
+ *
+ * [0x00, 0x00, 0xa0, 0xe1]
+ * mov r0, r0
+ *
+ * [0x00, 0x01, 0xa0, 0xe1]
+ * lsl r0, r0, 2
+ * # is this equivalent to mov r0, r0<<2?
+ * 0180afe1 invalid
+ * 018076e1 cmn r6, r1
+ * 015096e1 orrs r5, r6, r1
+ * 018086e1 orr r8, r6, r1
+ * 0180a6e1 invalid
+ * 0180d6e1 bics r8, r6, r1
+ * 0180d0e1 bics r8, r0, r1
+ * 8110d0e1 bics r1, r0, r1, lsl 1
+ * 1200dfe1 bics r0, pc, r2, lsl r0
+ * f110d0e1 ldrsh r1, [r0, 1]
+ * 0101a0e1 lsl r0, r1, 2
+ * 0110a0e1 mov r1, r1
+ * 0111a0e1 lsl r1, r1, 2
+ * 4110a0e1 asr r1, r1, 0x20
+ * 2110a0e1 lsr r1, r1, 0x20
+ *
+ */
generated by cgit v1.1 at 2024-11-22 17:46:40 +0000