diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/armv7.rs | 1016 |
1 files changed, 781 insertions, 235 deletions
diff --git a/src/armv7.rs b/src/armv7.rs index 50cde07..eb86faa 100644 --- a/src/armv7.rs +++ b/src/armv7.rs @@ -1,3 +1,7 @@ +/// Manual references in this crate, both figure and page numbers, are with respect to the document +/// `DDI0406C_d_armv7ar_arm.pdf` +/// `sha256: 294668ae6480133b32d85e9567cc77c5eb0e1232decdf42cac7ab480e884f6e0` + //#[cfg(feature="use-serde")] //use serde::{Serialize, Deserialize}; @@ -5,24 +9,46 @@ use std::fmt::{self, Display, Formatter}; use yaxpeax_arch::{Arch, Colorize, Decoder, LengthedInstruction, NoColors, ShowContextual, YaxColors}; -pub struct ConditionedOpcode(pub Opcode, pub ConditionCode); +pub struct ConditionedOpcode(pub Opcode, pub bool, pub ConditionCode); impl Display for ConditionedOpcode { fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> { - write!(f, "{}{}", self.0, self.1) + write!(f, "{}{}{}", self.0, if self.1 { "s" } else { "" }, self.2) } } pub struct NoContext; +fn reg_name_colorize<C: fmt::Display, Y: YaxColors<C>>(reg: Reg, colors: &Y) -> impl fmt::Display { + match reg.number() { + 0 => colors.register("r0"), + 1 => colors.register("r1"), + 2 => colors.register("r2"), + 3 => colors.register("r3"), + 4 => colors.register("r4"), + 5 => colors.register("r5"), + 6 => colors.register("r6"), + 7 => colors.register("r7"), + 8 => colors.register("r8"), + 9 => colors.register("sb"), + 10 => colors.register("r10"), + 11 => colors.register("fp"), + 12 => colors.register("ip"), + 13 => colors.register("sp"), + 14 => colors.register("lr"), + 15 => colors.program_counter("pc"), + _ => { unreachable!(); } + } +} + #[allow(non_snake_case)] impl <T: fmt::Write, Color: fmt::Display, Y: YaxColors<Color>> ShowContextual<u32, NoContext, Color, T, Y> for Instruction { fn contextualize(&self, colors: &Y, _address: u32, _context: Option<&NoContext>, out: &mut T) -> fmt::Result { match self.opcode { Opcode::LDR(true, false, false) => { match self.operands { - Operands::TwoRegImm(13, Rt, 4) => { - ConditionedOpcode(Opcode::POP, self.condition).colorize(colors, out)?; + [Operand::Reg(Rt), Operand::RegDisp(Reg { bits: 13 }, 4), Operand::Nothing, Operand::Nothing] => { + ConditionedOpcode(Opcode::POP, self.s, self.condition).colorize(colors, out)?; return write!(out, " {{{}}}", reg_name_colorize(Rt, colors)); }, _ => {} @@ -30,8 +56,8 @@ impl <T: fmt::Write, Color: fmt::Display, Y: YaxColors<Color>> ShowContextual<u3 }, Opcode::STR(false, true, true) => { match self.operands { - Operands::TwoRegImm(13, Rt, 4) => { - ConditionedOpcode(Opcode::PUSH, self.condition).colorize(colors, out)?; + [Operand::Reg(Rt), Operand::RegDisp(Reg { bits: 13 }, 4), Operand::Nothing, Operand::Nothing] => { + ConditionedOpcode(Opcode::PUSH, self.s, self.condition).colorize(colors, out)?; return write!(out, " {{{}}}", reg_name_colorize(Rt, colors)); }, _ => {} @@ -40,8 +66,8 @@ impl <T: fmt::Write, Color: fmt::Display, Y: YaxColors<Color>> ShowContextual<u3 Opcode::LDM(true, false, true, _usermode) => { // TODO: what indicates usermode in the ARM syntax? match self.operands { - Operands::RegRegList(13, list) => { - ConditionedOpcode(Opcode::POP, self.condition).colorize(colors, out)?; + [Operand::Reg(Reg { bits: 13 }), Operand::RegList(list), Operand::Nothing, Operand::Nothing] => { + ConditionedOpcode(Opcode::POP, self.s, self.condition).colorize(colors, out)?; write!(out, " ")?; return format_reg_list(out, list, colors); } @@ -51,8 +77,8 @@ impl <T: fmt::Write, Color: fmt::Display, Y: YaxColors<Color>> ShowContextual<u3 Opcode::STM(false, true, true, _usermode) => { // TODO: what indicates usermode in the ARM syntax? match self.operands { - Operands::RegRegList(13, list) => { - ConditionedOpcode(Opcode::PUSH, self.condition).colorize(colors, out)?; + [Operand::Reg(Reg { bits: 13 }), Operand::RegList(list), Operand::Nothing, Operand::Nothing] => { + ConditionedOpcode(Opcode::PUSH, self.s, self.condition).colorize(colors, out)?; write!(out, " ")?; return format_reg_list(out, list, colors); } @@ -67,41 +93,62 @@ impl <T: fmt::Write, Color: fmt::Display, Y: YaxColors<Color>> ShowContextual<u3 Opcode::STR(add, pre, wback) | Opcode::STRB(add, pre, wback) | Opcode::LDRB(add, pre, wback) => { - match self.operands { - Operands::TwoRegImm(Rn, Rt, imm) => { - ConditionedOpcode(self.opcode, self.condition).colorize(colors, out)?; + match &self.operands { + [Operand::Reg(Rn), Operand::Reg(Rt), Operand::Imm12(imm), Operand::Nothing] => { + ConditionedOpcode(self.opcode, self.s, self.condition).colorize(colors, out)?; + write!( + out, " {}, ", + reg_name_colorize(*Rt, colors), + )?; + return format_reg_imm_mem(out, *Rn, *imm, add, pre, wback, colors); + } + [Operand::Reg(Rn), Operand::RegDisp(Rt, offset), Operand::Nothing, Operand::Nothing] => { + ConditionedOpcode(self.opcode, self.s, self.condition).colorize(colors, out)?; write!( out, " {}, ", - reg_name_colorize(Rt, colors), + reg_name_colorize(*Rn, colors), )?; - return format_reg_imm_mem(out, Rn, imm, add, pre, wback, colors); + let (add, offset) = if *offset < 0 { + (false, -*offset as u16) + } else { + (true, *offset as u16) + }; + return format_reg_imm_mem(out, *Rt, offset, add, true, false, colors); } // TODO: this might not be necessary - Operands::RegImm(Rt, imm) => { - ConditionedOpcode(self.opcode, self.condition).colorize(colors, out)?; + [Operand::Reg(Rt), Operand::Imm12(imm), Operand::Nothing, Operand::Nothing] => { + ConditionedOpcode(self.opcode, self.s, self.condition).colorize(colors, out)?; write!( out, " {}, ", - reg_name_colorize(Rt, colors) + reg_name_colorize(*Rt, colors) )?; - return format_reg_imm_mem(out, 15, imm, add, pre, wback, colors); + return format_reg_imm_mem(out, Reg::from_u8(15), *imm, add, pre, wback, colors); }, - Operands::ThreeOperandWithShift(Rd, Rn, Rm, shift) => { - ConditionedOpcode(self.opcode, self.condition).colorize(colors, out)?; + [Operand::Reg(Rd), Operand::Reg(Rn), Operand::RegShift(shift), Operand::Nothing] => { + ConditionedOpcode(self.opcode, self.s, self.condition).colorize(colors, out)?; write!( out, " {}, ", - reg_name_colorize(Rn, colors) + reg_name_colorize(*Rn, colors) )?; - return format_reg_shift_mem(out, Rd, Rm, shift, add, pre, wback, colors); + return format_reg_shift_mem(out, *Rd, *shift, add, pre, wback, colors); } - _ => { unreachable!(); } + [Operand::Reg(Rt), Operand::RegDerefPostindexOffset(Rn, offset), Operand::Nothing, Operand::Nothing] => { + ConditionedOpcode(self.opcode, self.s, self.condition).colorize(colors, out)?; + write!( + out, " {}, ", + reg_name_colorize(*Rt, colors) + )?; + return format_reg_imm_mem(out, *Rt, *offset, true, false, true, colors); + } + o => { println!("other str/ldr operands: {:?}", o); unreachable!(); } } } // TODO: [add, pre, usermode] Opcode::STM(_add, _pre, wback, _usermode) | Opcode::LDM(_add, _pre, wback, _usermode) => { match self.operands { - Operands::RegRegList(Rr, list) => { - ConditionedOpcode(self.opcode, self.condition).colorize(colors, out)?; + [Operand::Reg(Rr), Operand::RegList(list), Operand::Nothing, Operand::Nothing] => { + ConditionedOpcode(self.opcode, self.s, self.condition).colorize(colors, out)?; write!( out, " {}{}, ", reg_name_colorize(Rr, colors), @@ -116,55 +163,23 @@ impl <T: fmt::Write, Color: fmt::Display, Y: YaxColors<Color>> ShowContextual<u3 write!(out, "incomplete: {:#x}", word) }, _ => { - ConditionedOpcode(self.opcode, self.condition).colorize(colors, out)?; - match self.operands { - Operands::RegisterList(list) => { - write!(out, " ")?; - format_reg_list(out, list, colors)?; - }, - Operands::OneOperand(a) => { - write!(out, " {}", reg_name_colorize(a, colors))?; - }, - Operands::TwoOperand(a, b) => { - write!(out, " {}, {}", reg_name_colorize(a, colors), reg_name_colorize(b, colors))?; - }, - Operands::RegImm(a, imm) => { - write!(out, " {}, {:#x}", reg_name_colorize(a, colors), imm)?; - }, - Operands::RegRegList(r, list) => { - write!(out, " {}, ", reg_name_colorize(r, colors))?; - format_reg_list(out, list, colors)?; - }, - Operands::TwoRegImm(_a, _b, _imm) => { - // TODO: - write!(out, " <unimplemented>")?; - }, - Operands::ThreeOperand(a, b, c) => { - write!(out, " {}, {}, {}", reg_name_colorize(a, colors), reg_name_colorize(b, colors), reg_name_colorize(c, colors))?; - }, - Operands::ThreeOperandImm(_a, _b, _imm) => { - // TODO: - write!(out, " <unimplemented>")?; - }, - Operands::ThreeOperandWithShift(a, b, c, shift) => { - write!(out, " {}, {}, ", reg_name_colorize(a, colors), reg_name_colorize(b, colors))?; - format_shift(out, c, shift, colors)?; - }, - Operands::MulThreeRegs(a, b, c) => { - write!(out, " {}, {}, {}", reg_name_colorize(a, colors), reg_name_colorize(b, colors), reg_name_colorize(c, colors))?; - }, - Operands::MulFourRegs(_a, _b, _c, _d) => { - // TODO: - write!(out, " <unimplemented>")?; - }, - Operands::BranchOffset(imm) => { - if imm < 0 { - write!(out, " $-{:#x}", (-imm) * 4)?; - } else { - write!(out, " $+{:#x}", imm * 4)?; - } + ConditionedOpcode(self.opcode, self.s, self.condition).colorize(colors, out)?; + let mut ops = self.operands.iter(); + if let Some(first_op) = ops.next() { + write!(out, " ")?; + first_op.colorize(colors, out)?; + } else { + return Ok(()); + } + + for op in ops { + if let Operand::Nothing = op { + break; } - }; + write!(out, ", ")?; + op.colorize(colors, out)?; + } + Ok(()) } } @@ -200,6 +215,8 @@ impl <T: fmt::Write, Color: fmt::Display, Y: YaxColors<Color>> Colorize<T, Color Opcode::SBC | Opcode::RSC | + Opcode::CLZ | + Opcode::MUL | Opcode::MLA | Opcode::UMAAL | @@ -207,7 +224,12 @@ impl <T: fmt::Write, Color: fmt::Display, Y: YaxColors<Color>> Colorize<T, Color Opcode::UMULL | Opcode::UMLAL | Opcode::SMULL | - Opcode::SMLAL => { write!(out, "{}", colors.arithmetic_op(self)) }, + Opcode::SMUL(_, _) | + Opcode::SMAL(_, _) | + Opcode::SMLA(_, _) | + Opcode::SMLAW(_) | + Opcode::SMLAL | + Opcode::SMLAL_halfword(_, _) => { write!(out, "{}", colors.arithmetic_op(self)) }, Opcode::PUSH | Opcode::POP => { write!(out, "{}", colors.stack_op(self)) }, @@ -243,6 +265,8 @@ impl <T: fmt::Write, Color: fmt::Display, Y: YaxColors<Color>> Colorize<T, Color Opcode::STRBT(_) | Opcode::SWP | Opcode::SWPB | + Opcode::MSR | + Opcode::MRS | Opcode::MOV | Opcode::MVN => { write!(out, "{}", colors.data_op(self)) }, } @@ -261,6 +285,7 @@ impl Display for Opcode { Opcode::BLX => { write!(f, "blx") }, Opcode::BX => { write!(f, "bx") }, Opcode::BXJ => { write!(f, "bxj") }, + Opcode::CLZ => { write!(f, "clz") }, Opcode::AND => { write!(f, "and") }, Opcode::EOR => { write!(f, "eor") }, Opcode::SUB => { write!(f, "sub") }, @@ -275,6 +300,8 @@ impl Display for Opcode { Opcode::CMN => { write!(f, "cmn") }, Opcode::ORR => { write!(f, "orr") }, Opcode::MOV => { write!(f, "mov") }, + Opcode::MSR => { write!(f, "msr") }, + Opcode::MRS => { write!(f, "mrs") }, Opcode::BIC => { write!(f, "bic") }, Opcode::MVN => { write!(f, "mvn") }, Opcode::LSL => { write!(f, "lsl") }, @@ -316,7 +343,22 @@ impl Display for Opcode { Opcode::UMULL => { write!(f, "umull") }, Opcode::UMLAL => { write!(f, "umlal") }, Opcode::SMULL => { write!(f, "smull") }, - Opcode::SMLAL => { write!(f, "smlal") } + Opcode::SMLA(first, second) => { + write!(f, "smla{}{}", if *first { "t" } else { "b" }, if *second { "t" } else { "b" }) + } + Opcode::SMLAL => { write!(f, "smlal") }, + Opcode::SMLAL_halfword(first, second) => { + write!(f, "smlal{}{}", if *first { "t" } else { "b" }, if *second { "t" } else { "b" }) + } + Opcode::SMUL(first, second) => { + write!(f, "smul{}{}", if *first { "t" } else { "b" }, if *second { "t" } else { "b" }) + }, + Opcode::SMAL(first, second) => { + write!(f, "smal{}{}", if *first { "t" } else { "b" }, if *second { "t" } else { "b" }) + }, + Opcode::SMLAW(second) => { + write!(f, "smlaw{}", if *second { "t" } else { "b" }) + }, } } } @@ -360,6 +402,9 @@ pub enum Opcode { RRX, ROR, ADR, + MSR, + MRS, + CLZ, LDREXH, STREXH, LDREXB, @@ -387,7 +432,12 @@ pub enum Opcode { UMULL, UMLAL, SMULL, - SMLAL + SMUL(bool, bool), + SMLA(bool, bool), + SMLAL, + SMLAL_halfword(bool, bool), + SMAL(bool, bool), + SMLAW(bool), } static DATA_PROCESSING_OPCODES: [Opcode; 16] = [ @@ -410,32 +460,178 @@ static DATA_PROCESSING_OPCODES: [Opcode; 16] = [ ]; #[derive(Debug, PartialEq, Eq, Copy, Clone)] -pub enum ShiftSpec { - Immediate(u8), - Register(u8) +#[repr(transparent)] +pub struct RegShift { + data: u16 +} + +impl RegShift { + fn into_shift(&self) -> RegShiftStyle { + if self.data & 0b1000 == 0 { + RegShiftStyle::RegImm(RegImmShift { data: self.data }) + } else { + RegShiftStyle::RegReg(RegRegShift { data: self.data }) + } + } + + fn from(data: u16) -> Self { + RegShift { data } + } +} + +pub enum RegShiftStyle { + RegImm(RegImmShift), + RegReg(RegRegShift), +} + +#[repr(transparent)] +pub struct RegRegShift { + data: u16 +} + +#[derive(Debug, PartialEq, Eq, Copy, Clone)] +pub enum ShiftStyle { + LSL = 0, + LSR = 1, + ASR = 2, + ROR = 3, +} + +impl ShiftStyle { + fn from(bits: u8) -> ShiftStyle { + match bits { + 0b00 => ShiftStyle::LSL, + 0b01 => ShiftStyle::LSR, + 0b10 => ShiftStyle::ASR, + 0b11 => ShiftStyle::ROR, + _ => unreachable!("bad ShiftStyle index") + } + } +} + +impl RegRegShift { + pub fn shifter(&self) -> Reg { + Reg::from_u8((self.data >> 8) as u8 & 0b1111) + } + pub fn stype(&self) -> ShiftStyle { + ShiftStyle::from((self.data >> 5) as u8 & 0b11) + } + pub fn shiftee(&self) -> Reg { + Reg::from_u8(self.data as u8 & 0b1111) + } +} + +#[repr(transparent)] +pub struct RegImmShift { + data: u16 +} + +impl RegImmShift { + pub fn imm(&self) -> u8 { + (self.data >> 7) as u8 & 0b11111 + } + pub fn stype(&self) -> ShiftStyle { + ShiftStyle::from((self.data >> 5) as u8 & 0b11) + } + pub fn shiftee(&self) -> Reg { + Reg::from_u8(self.data as u8 & 0b1111) + } +} + +#[derive(Copy, Clone, Debug, PartialEq, Eq)] +#[repr(transparent)] +pub struct Reg { + bits: u8 +} + +impl Reg { + pub fn from_u8(bits: u8) -> Reg { + if bits > 0b1111 { + panic!("register number out of range"); + } + + Reg { bits } + } + + pub fn number(&self) -> u8 { + self.bits + } } #[derive(Clone, Debug, PartialEq, Eq)] -pub enum Operands { - RegisterList(u16), - OneOperand(u8), - 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) +pub enum Operand { + Reg(Reg), + RegList(u16), + RegDeref(Reg), + RegDisp(Reg, i16), + RegShift(RegShift), + RegDerefRegShift(RegShift), + RegDerefPostindexOffset(Reg, u16), + RegDerefPostindexReg(Reg, Reg), + Imm12(u16), + Imm32(u32), + BranchOffset(i32), + ASPR, + CSPR, + SPSR, + Nothing, +} + +impl <T: fmt::Write, Color: fmt::Display, Y: YaxColors<Color>> Colorize<T, Color, Y> for Operand { + fn colorize(&self, colors: &Y, f: &mut T) -> fmt::Result { + match self { + Operand::RegList(list) => { + format_reg_list(f, *list, colors) + } + Operand::Reg(reg) => { + write!(f, "{}", reg_name_colorize(*reg, colors)) + } + Operand::RegDeref(reg) => { + write!(f, "[{}]", reg_name_colorize(*reg, colors)) + } + Operand::RegDisp(reg, imm) => { + write!(f, "[{} + {:#x}]", reg_name_colorize(*reg, colors), imm) + } + Operand::RegShift(shift) => { + format_shift(f, *shift, colors) + } + Operand::RegDerefRegShift(shift) => { + write!(f, "[")?; + format_shift(f, *shift, colors)?; + write!(f, "]") + } + Operand::RegDerefPostindexOffset(reg, offs) => { + write!(f, "[{}, {:#x}]", reg_name_colorize(*reg, colors), offs) + } + Operand::RegDerefPostindexReg(reg, offsreg) => { + write!(f, "[{}, {}]", reg_name_colorize(*reg, colors), reg_name_colorize(*offsreg, colors)) + } + Operand::Imm12(imm) => { + write!(f, "{:#x}", imm) + } + Operand::Imm32(imm) => { + write!(f, "{:#x}", imm) + } + Operand::BranchOffset(imm) => { + if *imm < 0 { + write!(f, " $-{:#x}", (-*imm) * 4) + } else { + write!(f, " $+{:#x}", *imm * 4) + } + } + Operand::ASPR => { write!(f, "aspr") }, + Operand::CSPR => { write!(f, "cspr") }, + Operand::SPSR => { write!(f, "spsr") }, + Operand::Nothing => { panic!("tried to print Nothing operand") }, + } + } } #[derive(Debug, PartialEq, Eq)] pub struct Instruction { pub condition: ConditionCode, pub opcode: Opcode, - pub operands: Operands, + pub operands: [Operand; 4], pub s: bool } @@ -474,7 +670,7 @@ impl Default for Instruction { Instruction { condition: ConditionCode::AL, opcode: Opcode::Invalid, - operands: Operands::BranchOffset(0), + operands: [Operand::Nothing, Operand::Nothing, Operand::Nothing, Operand::Nothing], s: false } } @@ -499,7 +695,7 @@ fn format_reg_list<T: fmt::Write, C: fmt::Display, Y: YaxColors<C>>(f: &mut T, m } else { tail = true; } - write!(f, "{}", reg_name_colorize(i, colors))?; + write!(f, "{}", reg_name_colorize(Reg::from_u8(i), colors))?; } i += 1; list >>= 1; @@ -508,46 +704,42 @@ fn format_reg_list<T: fmt::Write, C: fmt::Display, Y: YaxColors<C>>(f: &mut T, m } #[allow(non_snake_case)] -fn format_shift<T: fmt::Write, C: fmt::Display, Y: YaxColors<C>>(f: &mut T, Rm: u8, shift: ShiftSpec, colors: &Y) -> Result<(), fmt::Error> { - fn shift_tpe_to_str(tpe: u8) -> &'static str { +fn format_shift<T: fmt::Write, C: fmt::Display, Y: YaxColors<C>>(f: &mut T, shift: RegShift, colors: &Y) -> Result<(), fmt::Error> { + fn shift_tpe_to_str(tpe: ShiftStyle) -> &'static str { match tpe { - 0b00 => "lsl", - 0b01 => "lsr", - 0b10 => "asr", - 0b11 => "ror", - _ => { unreachable!(); } + ShiftStyle::LSL => "lsl", + ShiftStyle::LSR => "lsr", + ShiftStyle::ASR => "asr", + ShiftStyle::ROR => "ror", } } - match shift { - ShiftSpec::Immediate(0) => { - write!(f, "{}", reg_name_colorize(Rm, colors)) - }, - ShiftSpec::Immediate(v) => { - let tpe = v & 0x3; - let imm = v >> 2; - write!(f, "{}, {} {}", reg_name_colorize(Rm, colors), shift_tpe_to_str(tpe), imm) - }, - ShiftSpec::Register(v) => { - let tpe = v & 0x3; - let Rs = v >> 3; - write!(f, "{}, {} {}", reg_name_colorize(Rm, colors), shift_tpe_to_str(tpe), reg_name_colorize(Rs, colors)) + match shift.into_shift() { + RegShiftStyle::RegImm(imm_shift) => { + if imm_shift.imm() == 0 && imm_shift.stype() == ShiftStyle::LSL { + write!(f, "{}", reg_name_colorize(imm_shift.shiftee(), colors)) + } else { + write!(f, "{}, {} {}", reg_name_colorize(imm_shift.shiftee(), colors), shift_tpe_to_str(imm_shift.stype()), imm_shift.imm()) + } + } + RegShiftStyle::RegReg(reg_shift) => { + write!(f, "{}, {} {}", reg_name_colorize(reg_shift.shiftee(), colors), shift_tpe_to_str(reg_shift.stype()), reg_name_colorize(reg_shift.shifter(), colors)) }, } } #[allow(non_snake_case)] -fn format_reg_shift_mem<T: fmt::Write, C: fmt::Display, Y: YaxColors<C>>(f: &mut T, Rd: u8, Rm: u8, shift: ShiftSpec, add: bool, pre: bool, wback: bool, colors: &Y) -> Result<(), fmt::Error> { +fn format_reg_shift_mem<T: fmt::Write, C: fmt::Display, Y: YaxColors<C>>(f: &mut T, Rd: Reg, shift: RegShift, add: bool, pre: bool, wback: bool, colors: &Y) -> Result<(), fmt::Error> { let op = if add { "" } else { "-" }; match (pre, wback) { (true, true) => { write!(f, "[{}, {}", reg_name_colorize(Rd, colors), op)?; - format_shift(f, Rm, shift, colors)?; + format_shift(f, shift, colors)?; write!(f, "]!") }, (true, false) => { write!(f, "[{}, {}", reg_name_colorize(Rd, colors), op)?; - format_shift(f, Rm, shift, colors)?; + format_shift(f, shift, colors)?; write!(f, "]") }, (false, true) => { @@ -555,13 +747,13 @@ fn format_reg_shift_mem<T: fmt::Write, C: fmt::Display, Y: YaxColors<C>>(f: &mut }, (false, false) => { write!(f, "[{}], {}", reg_name_colorize(Rd, colors), op)?; - format_shift(f, Rm, shift, colors) + format_shift(f, shift, colors) } } } #[allow(non_snake_case)] -fn format_reg_imm_mem<T: fmt::Write, C: fmt::Display, Y: YaxColors<C>>(f: &mut T, Rn: u8, imm: u32, add: bool, pre: bool, wback: bool, colors: &Y) -> Result<(), fmt::Error> { +fn format_reg_imm_mem<T: fmt::Write, C: fmt::Display, Y: YaxColors<C>>(f: &mut T, Rn: Reg, imm: u16, add: bool, pre: bool, wback: bool, colors: &Y) -> Result<(), fmt::Error> { if imm != 0 { let op = if add { "" } else { "-" }; @@ -596,27 +788,6 @@ fn format_reg_imm_mem<T: fmt::Write, C: fmt::Display, Y: YaxColors<C>>(f: &mut T } } } -fn reg_name_colorize<C: fmt::Display, Y: YaxColors<C>>(num: u8, colors: &Y) -> impl fmt::Display { - match num { - 0 => colors.register("r0"), - 1 => colors.register("r1"), - 2 => colors.register("r2"), - 3 => colors.register("r3"), - 4 => colors.register("r4"), - 5 => colors.register("r5"), - 6 => colors.register("r6"), - 7 => colors.register("r7"), - 8 => colors.register("r8"), - 9 => colors.register("sb"), - 10 => colors.register("r10"), - 11 => colors.register("fp"), - 12 => colors.register("ip"), - 13 => colors.register("sp"), - 14 => colors.register("lr"), - 15 => colors.program_counter("pc"), - _ => { unreachable!(); } - } -} impl Display for Instruction { fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> { @@ -703,7 +874,9 @@ impl ConditionCode { } #[derive(Default, Debug)] -pub struct InstDecoder {} +pub struct InstDecoder { + system_mode: bool +} #[allow(non_snake_case)] impl Decoder<Instruction> for InstDecoder { @@ -743,11 +916,16 @@ impl Decoder<Instruction> for InstDecoder { 0b01 => { inst.opcode = Opcode::BLX; let operand = ((word & 0xffffff) as i32) << 8 >> 6; - inst.operands = Operands::BranchOffset( - operand | ( - ((word >> 23) & 0b10) as i32 - ) - ); + inst.operands = [ + Operand::BranchOffset( + operand | ( + ((word >> 23) & 0b10) as i32 + ) + ), + Operand::Nothing, + Operand::Nothing, + Operand::Nothing, + ]; } 0b10 => { inst.opcode = Opcode::Incomplete(word); @@ -801,11 +979,21 @@ impl Decoder<Instruction> for InstDecoder { match op { 0b000 => { inst.opcode = Opcode::MUL; - inst.operands = Operands::MulThreeRegs(R[3], R[0], R[1]); + inst.operands = [ + Operand::Reg(Reg::from_u8(R[3])), + Operand::Reg(Reg::from_u8(R[0])), + Operand::Reg(Reg::from_u8(R[1])), + Operand::Nothing, + ]; }, 0b001 => { inst.opcode = Opcode::MLA; - inst.operands = Operands::MulFourRegs(R[3], R[0], R[1], R[2]); + inst.operands = [ + Operand::Reg(Reg::from_u8(R[3])), + Operand::Reg(Reg::from_u8(R[0])), + Operand::Reg(Reg::from_u8(R[1])), + Operand::Reg(Reg::from_u8(R[2])), + ]; }, 0b010 => { if s { @@ -813,7 +1001,12 @@ impl Decoder<Instruction> for InstDecoder { return Err(DecodeError::InvalidOpcode); } inst.opcode = Opcode::UMAAL; - inst.operands = Operands::MulFourRegs(R[2], R[3], R[0], R[1]); + inst.operands = [ + Operand::Reg(Reg::from_u8(R[2])), + Operand::Reg(Reg::from_u8(R[3])), + Operand::Reg(Reg::from_u8(R[0])), + Operand::Reg(Reg::from_u8(R[1])), + ]; }, 0b011 => { if s { @@ -821,23 +1014,48 @@ impl Decoder<Instruction> for InstDecoder { return Err(DecodeError::InvalidOpcode); } inst.opcode = Opcode::MLS; - inst.operands = Operands::MulFourRegs(R[3], R[0], R[1], R[2]); + inst.operands = [ + Operand::Reg(Reg::from_u8(R[3])), + Operand::Reg(Reg::from_u8(R[0])), + Operand::Reg(Reg::from_u8(R[1])), + Operand::Reg(Reg::from_u8(R[2])), + ]; } 0b100 => { inst.opcode = Opcode::UMULL; - inst.operands = Operands::MulFourRegs(R[2], R[3], R[0], R[1]); + inst.operands = [ + Operand::Reg(Reg::from_u8(R[2])), + Operand::Reg(Reg::from_u8(R[3])), + Operand::Reg(Reg::from_u8(R[0])), + Operand::Reg(Reg::from_u8(R[1])), + ]; } 0b101 => { inst.opcode = Opcode::UMLAL; - inst.operands = Operands::MulFourRegs(R[2], R[3], R[0], R[1]); + inst.operands = [ + Operand::Reg(Reg::from_u8(R[2])), + Operand::Reg(Reg::from_u8(R[3])), + Operand::Reg(Reg::from_u8(R[0])), + Operand::Reg(Reg::from_u8(R[1])), + ]; } 0b110 => { inst.opcode = Opcode::SMULL; - inst.operands = Operands::MulFourRegs(R[2], R[3], R[0], R[1]); + inst.operands = [ + Operand::Reg(Reg::from_u8(R[2])), + Operand::Reg(Reg::from_u8(R[3])), + Operand::Reg(Reg::from_u8(R[0])), + Operand::Reg(Reg::from_u8(R[1])), + ]; } 0b111 => { inst.opcode = Opcode::SMLAL; - inst.operands = Operands::MulFourRegs(R[2], R[3], R[0], R[1]); + inst.operands = [ + Operand::Reg(Reg::from_u8(R[2])), + Operand::Reg(Reg::from_u8(R[3])), + Operand::Reg(Reg::from_u8(R[0])), + Operand::Reg(Reg::from_u8(R[1])), + ]; } _ => { unreachable!(format!("mul upcode: {:x}", op)) } } @@ -859,16 +1077,20 @@ impl Decoder<Instruction> for InstDecoder { 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 { 0b00 => { // |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 + // see page A5-203 match flags { 0b10000 => { inst.opcode = Opcode::SWP; - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Reg(Reg::from_u8(LoOffset)), + Operand::RegDeref(Reg::from_u8(Rn)), + Operand::Nothing, + ]; }, 0b10001 | 0b10010 | 0b10011 => { inst.opcode = Opcode::Invalid; @@ -876,43 +1098,98 @@ impl Decoder<Instruction> for InstDecoder { } 0b10100 => { inst.opcode = Opcode::SWPB; - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Reg(Reg::from_u8(LoOffset)), + Operand::RegDeref(Reg::from_u8(Rn)), + Operand::Nothing, + ]; }, 0b10101 | 0b10110 | 0b10111 => { inst.opcode = Opcode::Invalid; return Err(DecodeError::InvalidOpcode); } 0b11000 => { + // TODO: flag v6 inst.opcode = Opcode::STREX; - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Reg(Reg::from_u8(LoOffset)), + Operand::RegDeref(Reg::from_u8(Rn)), + Operand::Nothing, + ]; } 0b11001 => { + // TODO: flag v6 inst.opcode = Opcode::LDREX; - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::RegDeref(Reg::from_u8(Rn)), + Operand::Nothing, + Operand::Nothing, + ]; } 0b11010 => { inst.opcode = Opcode::STREXD; - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + if LoOffset == 0b1110 || (LoOffset & 1 == 1) || Rd == 15 || Rn == 15 { + // TODO: "unpredictable" + return Err(DecodeError::InvalidOperand); + } + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Reg(Reg::from_u8(LoOffset)), + Operand::Reg(Reg::from_u8(LoOffset + 1)), + Operand::RegDeref(Reg::from_u8(Rn)), + ]; } 0b11011 => { inst.opcode = Opcode::LDREXD; - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + if LoOffset == 0b1110 || (LoOffset & 1 == 1) || Rn == 15 { + // TODO: "unpredictable" + return Err(DecodeError::InvalidOperand); + } + inst.operands = [ + Operand::Reg(Reg::from_u8(LoOffset)), + Operand::Reg(Reg::from_u8(LoOffset + 1)), + Operand::RegDeref(Reg::from_u8(Rn)), + Operand::Nothing, + ]; } 0b11100 => { inst.opcode = Opcode::STREXB; - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Reg(Reg::from_u8(LoOffset)), + Operand::RegDeref(Reg::from_u8(Rn)), + Operand::Nothing, + ]; } 0b11101 => { inst.opcode = Opcode::LDREXB; - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + inst.operands = [ + Operand::Reg(Reg::from_u8(LoOffset)), + Operand::RegDeref(Reg::from_u8(Rn)), + Operand::Nothing, + Operand::Nothing, + ]; } 0b11110 => { inst.opcode = Opcode::STREXH; - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Reg(Reg::from_u8(LoOffset)), + Operand::RegDeref(Reg::from_u8(Rn)), + Operand::Nothing, + ]; } 0b11111 => { inst.opcode = Opcode::LDREXH; - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + inst.operands = [ + Operand::Reg(Reg::from_u8(LoOffset)), + Operand::RegDeref(Reg::from_u8(Rn)), + Operand::Nothing, + Operand::Nothing, + ]; } _ => { /* @@ -935,24 +1212,44 @@ impl Decoder<Instruction> for InstDecoder { 0b00010 => { // inst.opcode = Opcode::STRHT_sub; inst.opcode = Opcode::Incomplete(word); - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::RegDerefPostindexReg(Reg::from_u8(Rd), Reg::from_u8(LoOffset)), + Operand::Nothing, + Operand::Nothing, + ]; } 0b01010 => { // inst.opcode = Opcode::STRHT_add; inst.opcode = Opcode::Incomplete(word); - inst.operands = Operands::ThreeOperand(Rn, Rd, LoOffset); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::RegDerefPostindexReg(Reg::from_u8(Rd), Reg::from_u8(LoOffset)), + Operand::Nothing, + Operand::Nothing, + ]; } 0b00110 => { // inst.opcode = Opcode::STRHT_sub; inst.opcode = Opcode::Incomplete(word); let imm = (HiOffset << 4) as u16 | LoOffset as u16; - inst.operands = Operands::ThreeOperandImm(Rn, Rd, imm); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::RegDerefPostindexOffset(Reg::from_u8(Rd), imm), + Operand::Nothing, + Operand::Nothing, + ]; } 0b01110 => { // inst.opcode = Opcode::STRHT_add; inst.opcode = Opcode::Incomplete(word); let imm = (HiOffset << 4) as u16 | LoOffset as u16; - inst.operands = Operands::ThreeOperandImm(Rn, Rd, imm); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::RegDerefPostindexOffset(Reg::from_u8(Rd), imm), + Operand::Nothing, + Operand::Nothing, + ]; } _ => { return Err(DecodeError::Incomplete); @@ -979,9 +1276,10 @@ impl Decoder<Instruction> for InstDecoder { } } else { // we know this is data processing with imm or reg shift, OR - // misc instructions in Figure A3-4 + // misc instructions in Figure A5-4 if s == false && opcode >= 0b1000 && opcode < 0b1100 { + // Data-processing and miscellaneous instructions on page A5-194 let op2 = ((word >> 4) & 0x0f) as u8; // 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| @@ -991,34 +1289,140 @@ impl Decoder<Instruction> for InstDecoder { // misc instructions (page A5-194) match op2 { 0b000 => { - + if word & 0b1000000000 != 0 { + // TODO: ARMv7VE flag + let _M = (((word >> 9) & 1) << 4) | ((word >> 16) & 0x0f); + let _R = (word >> 22) & 1; + + if opcode & 0b01 == 0b01 { + inst.opcode = Opcode::MSR; + inst.operands[1] = Operand::Reg(Reg::from_u8(word as u8 & 0b1111)); + return Err(DecodeError::Incomplete); + } else { + inst.opcode = Opcode::MRS; + inst.operands[0] = Operand::Reg(Reg::from_u8((word >> 12) as u8 & 0b1111)); + return Err(DecodeError::Incomplete); + } + } else { + match opcode & 0b11 { + 0b00 | + 0b10 => { + inst.opcode = Opcode::MRS; + /* + let src = if self.system_mode { + let R = (word >> 22) & 1 != 0; + if R { + Operand::SPSR + } else { + Operand::CSPR + } + } else { + Operand::ASPR + }; + */ + inst.operands[0] = Operand::Reg(Reg::from_u8((word >> 12) as u8 & 0b1111)); + // TODO: + return Err(DecodeError::Incomplete); + } + 0b01 => { + inst.opcode = Opcode::MSR; + let mask = (word >> 16) & 0b1111; + if self.system_mode { + let R = (word >> 22) & 1 != 0; + let _dest = if R { + Operand::SPSR + } else { + Operand::CSPR + }; + // inst.operands[0] = /* masked write to dest */ + inst.operands[1] = Operand::Reg(Reg::from_u8(word as u8 & 0b1111)); + // TODO: + return Err(DecodeError::Incomplete); + } else { + if mask & 0b11 == 0 { + inst.operands[1] = Operand::Reg(Reg::from_u8(word as u8 & 0b1111)); + // TODO: + // inst.operands[0] = /* derived from mask >> 2 */ + return Err(DecodeError::Incomplete); + } else { + // MSR with op == 01, op != xx00 + return Err(DecodeError::InvalidOperand); + } + } + }, + 0b11 => { + if !self.system_mode { + return Err(DecodeError::InvalidOperand); + } + + inst.opcode = Opcode::MSR; + inst.operands[0] = Operand::Reg(Reg::from_u8((word >> 12) as u8 & 0b1111)); + // TODO: + return Err(DecodeError::Incomplete); + } + _ => { + unreachable!(); + } + } + } }, 0b001 => { - + match opcode & 0b11 { + 0b01 => { + inst.opcode = Opcode::BX; + inst.operands = [ + Operand::Reg(Reg::from_u8(word as u8 & 0b1111)), + Operand::Nothing, + Operand::Nothing, + Operand::Nothing, + ]; + } + 0b11 => { + inst.opcode = Opcode::CLZ; + inst.operands = [ + Operand::Reg(Reg::from_u8((word >> 12) as u8 & 0b1111)), + Operand::Reg(Reg::from_u8(word as u8 & 0b1111)), + Operand::Nothing, + Operand::Nothing, + ]; + } + _ => { + return Err(DecodeError::InvalidOpcode); + } + } }, 0b010 => { - + return Err(DecodeError::InvalidOpcode); }, 0b011 => { if opcode & 0b11 == 0b01 { inst.opcode = Opcode::BLX; - inst.operands = Operands::OneOperand((word & 0x0f) as u8); + inst.operands = [ + Operand::Reg(Reg::from_u8(word as u8 & 0x0f)), + Operand::Nothing, + Operand::Nothing, + Operand::Nothing, + ]; return Ok(()); } else { return Err(DecodeError::InvalidOpcode); } }, 0b100 => { - inst.opcode = Opcode::Incomplete(word); - return Ok(()); + // no row for op2 == 0b100 in table A5-14 (page A5-203) + return Err(DecodeError::InvalidOpcode); }, 0b101 => { - + // TODO: "Saturating addition and subtraction" page A5-200 + return Err(DecodeError::Incomplete); } 0b110 => { + // TODO: "ERET" page B9-1968 + return Err(DecodeError::Incomplete); }, 0b111 => { - + // TODO: "BKPT, HVC, SMC" from table A5-14/page A5-203 + return Err(DecodeError::Incomplete); }, _ => { unreachable!(); @@ -1026,11 +1430,84 @@ impl Decoder<Instruction> for InstDecoder { } } else { // |c o n d|0 0 0|1 0 x x|0|x x x x|x x x x|x x x x|1|x x|x|x x x x| - // multiply and multiply-accumulate - inst.opcode = Opcode::Incomplete(word); - return Ok(()); + // Halfword multiply and multiply accumulate on page A5-200 + match (word >> 21) & 0b11 { + 0b00 => { + let Rn_b = ((word >> 6) & 1) == 0; + let Rm_b = ((word >> 5) & 1) == 0; + inst.opcode = Opcode::SMLA(Rn_b, Rm_b); + inst.operands = [ + Operand::Reg(Reg::from_u8((word >> 16) as u8 & 0b1111)), + Operand::Reg(Reg::from_u8(word as u8 & 0b1111)), + Operand::Reg(Reg::from_u8((word >> 8) as u8 & 0b1111)), + Operand::Reg(Reg::from_u8((word >> 12) as u8 & 0b1111)), + ]; + return Ok(()); + }, + 0b01 => { + if word & 0b10000 == 0 { + // SMLAWB, SMLAWT page A8-631 + let Rm_b = ((word >> 5) & 1) == 0; + inst.opcode = Opcode::SMLAW(Rm_b); + inst.operands = [ + Operand::Reg(Reg::from_u8((word >> 16) as u8 & 0b1111)), + Operand::Reg(Reg::from_u8(word as u8 & 0b1111)), + Operand::Reg(Reg::from_u8((word >> 8) as u8 & 0b1111)), + Operand::Reg(Reg::from_u8((word >> 12) as u8 & 0b1111)), + ]; + return Ok(()); + } else { + // SMULWB, SMULWT page A8-649 + let Rm_b = ((word >> 5) & 1) == 0; + inst.opcode = Opcode::SMLAW(Rm_b); + inst.operands = [ + Operand::Reg(Reg::from_u8((word >> 16) as u8 & 0b1111)), + Operand::Reg(Reg::from_u8(word as u8 & 0b1111)), + Operand::Reg(Reg::from_u8((word >> 8) as u8 & 0b1111)), + Operand::Nothing, + ]; + return Ok(()); + } + } + 0b10 => { + let Rn_b = ((word >> 6) & 1) == 0; + let Rm_b = ((word >> 5) & 1) == 0; + inst.opcode = Opcode::SMLAL_halfword(Rn_b, Rm_b); + inst.operands = [ + Operand::Reg(Reg::from_u8((word >> 12) as u8 & 0b1111)), + Operand::Reg(Reg::from_u8((word >> 16) as u8 & 0b1111)), + Operand::Reg(Reg::from_u8(word as u8 & 0b1111)), + Operand::Reg(Reg::from_u8((word >> 8) as u8 & 0b1111)), + ]; + if inst.operands[0] == inst.operands[1] { + // TODO: this is actually "UNPREDICTABLE" (A8-627) + return Err(DecodeError::InvalidOperand); + } + return Ok(()); + } + 0b11 => { + let Rn_b = ((word >> 6) & 1) == 0; + let Rm_b = ((word >> 5) & 1) == 0; + inst.opcode = Opcode::SMUL(Rn_b, Rm_b); + inst.operands = [ + Operand::Reg(Reg::from_u8((word >> 16) as u8 & 0b1111)), + Operand::Reg(Reg::from_u8(word as u8 & 0b1111)), + Operand::Reg(Reg::from_u8((word >> 8) as u8 & 0b1111)), + Operand::Nothing, + ]; + if inst.operands[0] == inst.operands[1] { + // TODO: this is actually "UNPREDICTABLE" (A8-627) + return Err(DecodeError::InvalidOperand); + } + return Ok(()); + } + _ => { + unreachable!(); + } + } } } else { + // `Table A5-3 Data-processing (register) instructions`, not op=10xx0. if opcode >= 16 { unreachable!(); } @@ -1040,45 +1517,63 @@ impl Decoder<Instruction> for InstDecoder { // 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| + // |c o n d|0 0 0|x x 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 shift_spec = (word & 0xfff) as u16; + let word = word >> 12; let Rd = (word & 0x0f) as u8; let Rn = ((word >> 4) & 0x0f) as u8; (Rn, Rd, shift_spec, Rm) }; - if shift_spec == 0 { + if shift_spec & 0xff0 == 0 { if (0b1101 & opcode) == 0b1101 { + if Rn != 0 { + // this is really a "should be zero" situation + return Err(DecodeError::Incomplete); + } // MOV or MVN - inst.operands = Operands::TwoOperand(Rd, Rm); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Reg(Reg::from_u8(Rm)), + Operand::Nothing, + Operand::Nothing + ]; } else { - inst.operands = Operands::ThreeOperand(Rd, Rn, Rm); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Reg(Reg::from_u8(Rn)), + Operand::Reg(Reg::from_u8(Rm)), + Operand::Nothing + ]; } } else { - /* - * TODO: look at how this interacts with mov and mvn - */ - inst.operands = Operands::ThreeOperandWithShift(Rd, Rn, Rm, ShiftSpec::Immediate(shift_spec)); + if opcode == 0b1101 && Rn != 0 { + // Rn "should" be zero + return Err(DecodeError::Incomplete); + } + + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Reg(Reg::from_u8(Rn)), + Operand::RegShift(RegShift::from(shift_spec)), + Operand::Nothing + ]; } } 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 (Rn, Rd, shift_spec) = { + let shift_spec = (word & 0xfff) as u16; + let word = word >> 12; let Rd = (word & 0x0f) as u8; let Rn = ((word >> 4) & 0x0f) as u8; - (Rn, Rd, shift_spec, Rm) + (Rn, Rd, shift_spec) }; // page A5-200 indicates that saturating add and subtract should be // here? @@ -1087,7 +1582,13 @@ impl Decoder<Instruction> for InstDecoder { inst.opcode = Opcode::Invalid; return Err(DecodeError::InvalidOpcode); } else { - inst.operands = Operands::ThreeOperandWithShift(Rd, Rn, Rm, ShiftSpec::Register(shift_spec)); + // TODO: unsure about this RegShift... + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Reg(Reg::from_u8(Rn)), + Operand::RegShift(RegShift::from(shift_spec)), + Operand::Nothing, + ]; } } } @@ -1106,34 +1607,46 @@ impl Decoder<Instruction> for InstDecoder { }; 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) + // |c o n d|0 0 1|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| + // which means 16-bit immediate load, high half immediate load, or MSR (immediate) + // + hints. + // See table A5-2, page A5-194. inst.opcode = Opcode::Incomplete(word); return Ok(()); } else { + // Data-processing (immediate) + // Page A5-197 if opcode >= 16 { unreachable!(); } inst.opcode = DATA_PROCESSING_OPCODES[opcode as usize]; inst.set_s(s); - let (Rn, imm) = { - let imm = word & 0x0000ffff; - let word = word >> 16; - ((word & 0x0f) as u8, imm) + let (Rn, Rd, imm) = { + let rot = word & 0x00000f00; + let imm = (word & 0x000000ff); + let imm = (imm as u32).rotate_right(2 * (rot >> 8)); + ((word >> 16) as u8 & 0x0f, (word >> 12) as u8 & 0x0f, imm) }; if (opcode == 0b0010 || opcode == 0b0100) && Rn == 0b1111 { inst.opcode = Opcode::ADR; } match opcode { 0b1101 => { - inst.operands = Operands::RegImm( - ((word >> 12) & 0xf) as u8, - (word & 0x0fff) as u32 - ); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Imm32(imm), + Operand::Nothing, + Operand::Nothing, + ]; } _ => { - inst.operands = Operands::RegImm(Rn, imm); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rd)), + Operand::Reg(Reg::from_u8(Rn)), + Operand::Imm32(imm), + Operand::Nothing, + ]; } } @@ -1141,6 +1654,9 @@ impl Decoder<Instruction> for InstDecoder { /* ... */ } 0b010 => { + // Load/store word and unsigned byte + // A5.3 + // Page A5-206 let Rn = ((word >> 16) & 0x0f) as u8; let op = ((word >> 20) & 0x1f) as u8; let add = (op & 0b01000) != 0; @@ -1177,7 +1693,12 @@ impl Decoder<Instruction> for InstDecoder { 0b000 => Opcode::STR(add, pre, wback), 0b001 => { if Rn == 0b1111 { - inst.operands = Operands::RegImm(Rt, imm.into()); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rt)), + Operand::RegDisp(Reg::from_u8(Rn), imm as u16 as i16), + Operand::Nothing, + Operand::Nothing, + ]; inst.opcode = Opcode::LDR(add, pre, wback); return Ok(()); } @@ -1186,7 +1707,12 @@ impl Decoder<Instruction> for InstDecoder { 0b100 => Opcode::STRB(add, pre, wback), 0b101 => { if Rn == 0b1111 { - inst.operands = Operands::RegImm(Rt, imm.into()); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rt)), + Operand::RegDisp(Reg::from_u8(Rn), imm as u16 as i16), + Operand::Nothing, + Operand::Nothing, + ]; inst.opcode = Opcode::LDRB(add, pre, wback); return Ok(()); } @@ -1195,7 +1721,12 @@ impl Decoder<Instruction> for InstDecoder { _ => { unreachable!(); } }; } - inst.operands = Operands::TwoRegImm(Rn, Rt, imm.into()); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rt)), + Operand::RegDerefPostindexOffset(Reg::from_u8(Rn), imm as u16), + Operand::Nothing, + Operand::Nothing, + ]; }, 0b011 => { // page A5-192 to distinguish the following: @@ -1220,7 +1751,7 @@ impl Decoder<Instruction> for InstDecoder { xx1x1 not 0x111 -> LDRB (register) 0x111 -> LDRBT */ - let Rn = ((word >> 16) & 0x0f) as u8; + 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| @@ -1255,15 +1786,18 @@ impl Decoder<Instruction> for InstDecoder { _ => { 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, shift) = { + let shift = (word & 0xfff) as u16; + let word = word >> 12; let Rt = (word & 0xf) as u8; - (Rt, Rm, shift) + (Rt, shift) }; - inst.operands = Operands::ThreeOperandWithShift(Rn, Rt, Rm, ShiftSpec::Immediate(shift)); + inst.operands = [ + Operand::Reg(Reg::from_u8(Rt)), + Operand::RegDerefRegShift(RegShift::from(shift)), + Operand::Nothing, + Operand::Nothing, + ]; } return Ok(()); }, @@ -1277,24 +1811,36 @@ impl Decoder<Instruction> for InstDecoder { let pre = (op & 0b010000) != 0; let usermode = (op & 0b000100) != 0; inst.opcode = if (op & 1) == 0 { - Opcode::STM(add, pre, wback, usermode) - } else { - Opcode::LDM(add, pre, wback, usermode) - }; - inst.operands = Operands::RegRegList( - ((word >> 16) & 0xf) as u8, - (word & 0xffff) as u16 - ); + Opcode::STM(add, pre, wback, usermode) + } else { + Opcode::LDM(add, pre, wback, usermode) + }; + inst.operands = [ + Operand::Reg(Reg::from_u8(((word >> 16) & 0xf) as u8)), + Operand::RegList((word & 0xffff) as u16), + Operand::Nothing, + Operand::Nothing, + ]; } else if op < 0b110000 { // 10xxxx // the + 1 is to compensate for an architecturally-defined initial offset inst.opcode = Opcode::B; - inst.operands = Operands::BranchOffset(((word & 0x00ffff) + 1) as i16 as i32); + inst.operands = [ + Operand::BranchOffset(((word & 0x00ffff) + 1) as i16 as i32), + Operand::Nothing, + Operand::Nothing, + Operand::Nothing, + ]; } else { // 11xxxx // the + 1 is to compensate for an architecturally-defined initial offset inst.opcode = Opcode::BL; - inst.operands = Operands::BranchOffset(((word & 0x00ffff) + 1) as i16 as i32); + inst.operands = [ + Operand::BranchOffset(((word & 0x00ffff) + 1) as i16 as i32), + Operand::Nothing, + Operand::Nothing, + Operand::Nothing, + ]; } }, 0b110 | 0b111 => { @@ -1322,7 +1868,7 @@ impl Arch for ARMv7 { type Instruction = Instruction; type DecodeError = DecodeError; type Decoder = InstDecoder; - type Operand = Operands; + type Operand = Operand; } |