diff options
Diffstat (limited to 'src/armv7/thumb.rs')
| -rw-r--r-- | src/armv7/thumb.rs | 193 |
1 files changed, 188 insertions, 5 deletions
diff --git a/src/armv7/thumb.rs b/src/armv7/thumb.rs index 2743c13..ab28be8 100644 --- a/src/armv7/thumb.rs +++ b/src/armv7/thumb.rs @@ -4,6 +4,7 @@ use std::fmt; use armv7::ConditionCode; use armv7::DecodeError; +use armv7::CReg; use armv7::Reg; use armv7::RegShift; use armv7::Operand; @@ -1025,8 +1026,9 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I } else { // `Coprocessor, Advanced SIMD, and Floating-point instructions` (`A6-249`) // v6T2 - eprintln!("TODO: coproc/simd/fp"); - return Err(DecodeError::Incomplete); + // op1 == 01, op2 == 1xxxxxx + // this means `assert!(instr2[10])` + return decode_table_a6_30(decoder, inst, instr2, lower2); } } else if opword < 0b11111 { // op1 == 0b10 @@ -1253,6 +1255,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I } else { // `Data-processing (plain binary immediate)` (`A6-232`) // v6T2 + // aka table `A6-12` let op = instr2[4..9].load::<u8>(); let i = instr2[10..11].load::<u16>(); inst.s = false; @@ -3028,7 +3031,6 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I } else { if op2[3] { // `Long multiply, long multiply accumulate, and divide` (`A6-248`) - return Err(DecodeError::Incomplete); let op1 = instr2[4..7].load::<usize>(); let op2 = lower2[4..8].load::<usize>(); @@ -3302,13 +3304,15 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I } } - return Err(DecodeError::Incomplete); } } } } else { // `Coprocessor, Advanced SIMD, and Floating-point instructions` (`A6-249`) - return Err(DecodeError::Incomplete); + // v6T2 + // op1 == 11, op2 == 1xxxxxx + // this means `assert!(instr2[10])` + return decode_table_a6_30(decoder, inst, instr2, lower2); } } } else { @@ -4180,3 +4184,182 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I } Ok(()) } + +fn decode_table_a6_30(decoder: &InstDecoder, inst: &mut Instruction, instr2: BitArray<Lsb0, [u16; 1]>, lower2: BitArray<Lsb0, [u16; 1]>) -> Result<(), DecodeError> { + // implementation of table `A6-30 Coprocessor, Advanced SIMD, and Floating-point instructions` + let op1 = instr2[4..10].load::<usize>(); + if op1 & 0b11_1110 == 0b00_0000 { + inst.opcode = Opcode::UDF; + inst.operands = [ + Operand::Nothing, + Operand::Nothing, + Operand::Nothing, + Operand::Nothing, + ]; + return Err(DecodeError::InvalidOpcode); + } else if op1 & 0b110000 == 0b110000 { + // TODO: `Advanced SIMD data-processing instructions on A7-259` + return Err(DecodeError::Incomplete); + } else { + let coproc = lower2[8..12].load::<u8>(); + if coproc & 0b1110 != 0b1010 { + // `not 101x` rows + if op1 == 0b000100 { + // `MCRR, MCRR2 on page A8-479` + let crm = lower2[0..4].load::<u8>(); + let opc1 = lower2[4..8].load::<u8>(); + let rt = lower2[12..16].load::<u8>(); + let rt2 = instr2[0..4].load::<u8>(); + if instr2[12] { + inst.opcode = Opcode::MCRR2(coproc, opc1); + } else { + inst.opcode = Opcode::MCRR(coproc, opc1); + } + inst.operands = [ + Operand::Reg(Reg::from_u8(rt)), + Operand::Reg(Reg::from_u8(rt2)), + Operand::CReg(CReg::from_u8(crm)), + Operand::Nothing, + ]; + } else if op1 == 0b000101 { + // `MRRC, MRRC2 on page A8-495` + let crm = lower2[0..4].load::<u8>(); + let opc1 = lower2[4..8].load::<u8>(); + let rt = lower2[12..16].load::<u8>(); + let rt2 = instr2[0..4].load::<u8>(); + // manual typo!! the manual spells the operands + // `<coproc>, <opc>, <Rt>, <Rt2>, <CRm>` + // but the operand name is `opc1`! + // + // this is a very uninteresting typo, but fun to spot nonetheless + if instr2[12] { + inst.opcode = Opcode::MRRC2(coproc, opc1); + } else { + inst.opcode = Opcode::MRRC(coproc, opc1); + } + inst.operands = [ + Operand::Reg(Reg::from_u8(rt)), + Operand::Reg(Reg::from_u8(rt2)), + Operand::CReg(CReg::from_u8(crm)), + Operand::Nothing, + ]; + } else { + if op1 & 1 == 0 { + // `STC, STC2 on page A8-663` + let p = instr2[8]; + let u = instr2[7]; + let w = instr2[5]; + let rn = instr2[0..4].load::<u8>(); + let crd = lower2[12..16].load::<u8>(); + let imm8 = lower2[0..8].load::<u16>(); + + if instr2[12] { + if instr2[6] { + inst.opcode = Opcode::STC2L(coproc); + } else { + inst.opcode = Opcode::STC2(coproc); + } + } else { + if instr2[6] { + inst.opcode = Opcode::STCL(coproc); + } else { + inst.opcode = Opcode::STC(coproc); + } + } + inst.operands = [ + Operand::CReg(CReg::from_u8(crd)), + if p { + Operand::RegDerefPreindexOffset( + Reg::from_u8(rn), + imm8 << 2, + u, + w, + ) + } else { + if w { + Operand::RegDerefPostindexOffset( + Reg::from_u8(rn), + imm8 << 2, + u, + false, // TODO: wback? this is true? not true? + ) + } else { + Operand::RegDeref(Reg::from_u8(rn)) + } + }, + if !p && !w { + Operand::CoprocOption(imm8 as u8) + } else { + Operand::Nothing + }, + Operand::Nothing, + ]; + } else { + // `LDC, LDC2 (immediate or literal) on A8-393 or A8-395` + let p = instr2[8]; + let u = instr2[7]; + let w = instr2[5]; + let rn = instr2[0..4].load::<u8>(); + let crd = lower2[12..16].load::<u8>(); + let imm8 = lower2[0..8].load::<u16>(); + + if rn == 0b1111 { + // `LDC, LDC2 (literal) on A8-395` + // notable for rejecting writeback + if w { + decoder.unpredictable()?; + } + } else { + // `LDC, LDC2 (immediate) on A8-393` + } + + if instr2[12] { + if instr2[6] { + inst.opcode = Opcode::LDC2L(coproc); + } else { + inst.opcode = Opcode::LDC2(coproc); + } + } else { + if instr2[6] { + inst.opcode = Opcode::LDCL(coproc); + } else { + inst.opcode = Opcode::LDC(coproc); + } + } + inst.operands = [ + Operand::CReg(CReg::from_u8(crd)), + if p { + Operand::RegDerefPreindexOffset( + Reg::from_u8(rn), + imm8 << 2, + u, + w, + ) + } else { + if w { + Operand::RegDerefPostindexOffset( + Reg::from_u8(rn), + imm8 << 2, + u, + false, // TODO: wback? this is true? not true? + ) + } else { + Operand::RegDeref(Reg::from_u8(rn)) + } + }, + if !p && !w { + Operand::CoprocOption(imm8 as u8) + } else { + Operand::Nothing + }, + Operand::Nothing, + ]; + } + } + } else { + // `101x` rows + return Err(DecodeError::Incomplete); + } + } + Ok(()) +} |