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-rw-r--r--src/lib.rs144
1 files changed, 87 insertions, 57 deletions
diff --git a/src/lib.rs b/src/lib.rs
index 3a611b5..c29f190 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -5,6 +5,8 @@ extern crate serde;
//#[cfg(feature="use-serde")]
//use serde::{Serialize, Deserialize};
+use std::fmt;
+
extern crate yaxpeax_arch;
use yaxpeax_arch::{Arch, Decoder, LengthedInstruction};
@@ -23,6 +25,7 @@ pub struct PIC18;
impl Arch for PIC18 {
type Address = u32;
type Instruction = Instruction;
+ type DecodeError = DecodeError;
type Decoder = InstDecoder;
type Operand = Operand;
}
@@ -53,6 +56,34 @@ impl LengthedInstruction for Instruction {
}
}
+#[derive(Debug, PartialEq)]
+pub enum DecodeError {
+ ExhaustedInput,
+ InvalidOpcode,
+ InvalidOperand,
+}
+
+impl fmt::Display for DecodeError {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ DecodeError::ExhaustedInput => write!(f, "exhausted input"),
+ DecodeError::InvalidOpcode => write!(f, "invalid opcode"),
+ DecodeError::InvalidOperand => write!(f, "invalid operand"),
+ }
+ }
+}
+
+impl yaxpeax_arch::DecodeError for DecodeError {
+ fn data_exhausted(&self) -> bool { self == &DecodeError::ExhaustedInput }
+ fn bad_opcode(&self) -> bool { self == &DecodeError::InvalidOpcode }
+ fn bad_operand(&self) -> bool { self == &DecodeError::InvalidOperand }
+}
+
+impl yaxpeax_arch::Instruction for Instruction {
+ // TODO: this is wrong!!
+ fn well_defined(&self) -> bool { true }
+}
+
impl Instruction {
pub fn blank() -> Instruction {
Instruction {
@@ -163,18 +194,17 @@ pub enum Operand {
pub struct InstDecoder {}
impl Decoder<Instruction> for InstDecoder {
- fn decode<T: IntoIterator<Item=u8>>(&self, bytes: T) -> Option<Instruction> {
+ type Error = DecodeError;
+
+ fn decode<T: IntoIterator<Item=u8>>(&self, bytes: T) -> Result<Instruction, Self::Error> {
let mut blank = Instruction::blank();
- match self.decode_into(&mut blank, bytes) {
- Some(_) => Some(blank),
- None => None
- }
+ self.decode_into(&mut blank, bytes).map(|_: ()| blank)
}
- fn decode_into<T: IntoIterator<Item=u8>>(&self, inst: &mut Instruction, bytes: T) -> Option<()> {
+ fn decode_into<T: IntoIterator<Item=u8>>(&self, inst: &mut Instruction, bytes: T) -> Result<(), Self::Error> {
let mut bytes_iter = bytes.into_iter();
let word: Vec<u8> = bytes_iter.by_ref().take(2).collect();
if word.len() != 2 {
- return None;
+ return Err(DecodeError::ExhaustedInput);
}
// println!("Decoding {:x?}", word);
@@ -183,87 +213,87 @@ impl Decoder<Instruction> for InstDecoder {
match word[0] {
0x00 => {
inst.opcode = Opcode::NOP;
- Some(())
+ Ok(())
},
0b00000011 => {
inst.opcode = Opcode::SLEEP;
- Some(())
+ Ok(())
},
0b00000100 => {
inst.opcode = Opcode::CLRWDT;
- Some(())
+ Ok(())
},
0b00000101 => {
inst.opcode = Opcode::PUSH;
- Some(())
+ Ok(())
},
0b00000110 => {
inst.opcode = Opcode::POP;
- Some(())
+ Ok(())
},
0b00000111 => {
inst.opcode = Opcode::DAW;
- Some(())
+ Ok(())
},
0b00001000 => {
inst.opcode = Opcode::TBLRD_S;
- Some(())
+ Ok(())
},
0b00001001 => {
inst.opcode = Opcode::TBLRD_S_I;
- Some(())
+ Ok(())
},
0b00001010 => {
inst.opcode = Opcode::TBLRD_S_D;
- Some(())
+ Ok(())
},
0b00001011 => {
inst.opcode = Opcode::TBLRD_I_S;
- Some(())
+ Ok(())
},
0b00001100 => {
inst.opcode = Opcode::TBLWT_S;
- Some(())
+ Ok(())
},
0b00001101 => {
inst.opcode = Opcode::TBLWT_S_I;
- Some(())
+ Ok(())
},
0b00001110 => {
inst.opcode = Opcode::TBLWT_S_D;
- Some(())
+ Ok(())
},
0b00001111 => {
inst.opcode = Opcode::TBLWT_I_S;
- Some(())
+ Ok(())
},
0b00010000 => {
inst.opcode = Opcode::RETFIE;
- Some(())
+ Ok(())
},
0b00010001 => {
inst.opcode = Opcode::RETFIE_FAST;
- Some(())
+ Ok(())
},
0b00010010 => {
inst.opcode = Opcode::RETURN;
- Some(())
+ Ok(())
},
0b00010011 => {
inst.opcode = Opcode::RETURN_FAST;
- Some(())
+ Ok(())
},
0b00010100 => {
inst.opcode = Opcode::CALLW;
- Some(())
+ Ok(())
},
0b11111111 => {
inst.opcode = Opcode::RESET;
- Some(())
+ Ok(())
},
_ => {
inst.opcode = Opcode::Invalid(word[0], word[1]);
- None
+ Err(DecodeError::InvalidOpcode)
}
}
},
@@ -271,60 +301,60 @@ impl Decoder<Instruction> for InstDecoder {
inst.opcode = Opcode::MOVLB;
// this ignores high nibble of low word. ok by isa, but...
inst.operands[0] = Operand::ImmediateU8(word[0] & 0x0f);
- Some(())
+ Ok(())
},
0x02 | 0x03 => {
inst.opcode = Opcode::MULWF;
let a = (word[1] & 0x01) == 1;
inst.operands[0] = Operand::File(word[0], a);
- Some(())
+ Ok(())
},
0x04 | 0x05 | 0x06 | 0x07 => {
inst.opcode = Opcode::DECF;
let d = ((word[1] >> 1) & 0x01u8) == 1u8;
let a = (word[1] & 0x01) == 1;
inst.operands[0] = Operand::RedirectableFile(word[0], a, d);
- Some(())
+ Ok(())
},
0x08 => {
inst.opcode = Opcode::SUBLW;
inst.operands[0] = Operand::ImmediateU8(word[0]);
- Some(())
+ Ok(())
},
0x09 => {
inst.opcode = Opcode::IORLW;
inst.operands[0] = Operand::ImmediateU8(word[0]);
- Some(())
+ Ok(())
},
0x0a => {
inst.opcode = Opcode::XORLW;
inst.operands[0] = Operand::ImmediateU8(word[0]);
- Some(())
+ Ok(())
},
0x0b => {
inst.opcode = Opcode::ANDLW;
inst.operands[0] = Operand::ImmediateU8(word[0]);
- Some(())
+ Ok(())
},
0x0c => {
inst.opcode = Opcode::RETLW;
inst.operands[0] = Operand::ImmediateU8(word[0]);
- Some(())
+ Ok(())
},
0x0d => {
inst.opcode = Opcode::MULLW;
inst.operands[0] = Operand::ImmediateU8(word[0]);
- Some(())
+ Ok(())
},
0x0e => {
inst.opcode = Opcode::MOVLW;
inst.operands[0] = Operand::ImmediateU8(word[0]);
- Some(())
+ Ok(())
},
0x0f => {
inst.opcode = Opcode::ADDLW;
inst.operands[0] = Operand::ImmediateU8(word[0]);
- Some(())
+ Ok(())
},
x if x >= 0x10 && x < 0b01100000 => {
let da = x & 0b0011;
@@ -352,7 +382,7 @@ impl Decoder<Instruction> for InstDecoder {
Opcode::SUBWF
][opc as usize];
inst.operands[0] = Operand::RedirectableFile(word[0], (da & 0x01) == 0x01, (da & 0x02) == 0x02);
- Some(())
+ Ok(())
},
x if x >= 0b01100000 && x < 0b01110000 => {
let a = x & 1;
@@ -368,7 +398,7 @@ impl Decoder<Instruction> for InstDecoder {
Opcode::MOVWF
][opc as usize];
inst.operands[0] = Operand::File(word[0], a == 1);
- Some(())
+ Ok(())
},
x if x >= 0b01110000 && x < 0b11000000 => {
let a = x & 1;
@@ -383,23 +413,23 @@ impl Decoder<Instruction> for InstDecoder {
let bit = (x >> 1) & 0b0000111;
inst.operands[0] = Operand::File(word[0], a == 1);
inst.operands[1] = Operand::ImmediateU8(bit);
- Some(())
+ Ok(())
},
x if x >= 0b11000000 && x < 0b11010000 => {
inst.opcode = Opcode::MOVFF;
let word2: Vec<u8> = bytes_iter.take(2).collect();
if word2.len() != 2 {
- return None;
+ return Err(DecodeError::ExhaustedInput);
}
if word2[1] & 0xf0 != 0xf0 {
- return None;
+ return Err(DecodeError::InvalidOperand);
}
let src = (word[0] as u16) | ((word[1] as u16 & 0x0f) << 8);
let dest = (word2[0] as u16) | ((word2[1] as u16 & 0x0f) << 8);
inst.operands[0] = Operand::AbsoluteFile(src);
inst.operands[1] = Operand::AbsoluteFile(dest);
- Some(())
+ Ok(())
},
x if x >= 0b11010000 && x < 0b11100000 => {
inst.opcode = [
@@ -407,7 +437,7 @@ impl Decoder<Instruction> for InstDecoder {
Opcode::RCALL
][((x >> 3) & 1) as usize];
inst.operands[0] = Operand::ImmediateU32((((x & 0b111) as u32) << 8) | word[0] as u32);
- Some(())
+ Ok(())
},
x if x >= 0b11100000 && x < 0b11101000 => {
let opc = x & 0b00000111;
@@ -422,17 +452,17 @@ impl Decoder<Instruction> for InstDecoder {
Opcode::BNN
][opc as usize];
inst.operands[0] = Operand::ImmediateU8(word[0]);
- Some(())
+ Ok(())
},
0xee => {
let f_k_msb = word[0];
let word2: Vec<u8> = bytes_iter.take(2).collect();
if word2.len() != 2 {
- return None;
+ return Err(DecodeError::ExhaustedInput);
}
if (word2[1] & 0xf0) != 0xf0 {
- return None; // invalid instruction
+ return Err(DecodeError::InvalidOperand);
}
inst.opcode = Opcode::LFSR;
@@ -443,7 +473,7 @@ impl Decoder<Instruction> for InstDecoder {
inst.operands[0] = Operand::FileFSR(f);
inst.operands[1] = Operand::ImmediateU32(((k_msb as u32) << 8) | (k_lsb as u32));
- Some(())
+ Ok(())
}
/* ... */
0xeb | 0xec => {
@@ -451,37 +481,37 @@ impl Decoder<Instruction> for InstDecoder {
let k_lsb = word[0];
let word2: Vec<u8> = bytes_iter.take(2).collect();
if word2.len() != 2 {
- return None;
+ return Err(DecodeError::ExhaustedInput);
}
if (word2[1] & 0xf0) != 0xf0 {
- return None; // invalid instruction
+ return Err(DecodeError::InvalidOperand);
}
let k_msb = (((word2[1] & 0xf) as u32) << 8) | word2[0] as u32;
inst.opcode = Opcode::CALL;
inst.operands[0] = Operand::ImmediateU32(((k_msb << 8) | k_lsb as u32) << 1);
- Some(())
+ Ok(())
}
0xef => {
let k_lsb = word[0];
let word2: Vec<u8> = bytes_iter.take(2).collect();
if word2.len() != 2 {
- return None;
+ return Err(DecodeError::ExhaustedInput);
}
if (word2[1] & 0xf0) != 0xf0 {
- return None; // invalid instruction
+ return Err(DecodeError::InvalidOperand);
}
let k_msb = (((word2[1] & 0xf) as u32) << 8) | word2[0] as u32;
inst.opcode = Opcode::GOTO;
inst.operands[0] = Operand::ImmediateU32(((k_msb << 8) | k_lsb as u32) << 1);
- Some(())
+ Ok(())
}
- _ => None
+ _ => Err(DecodeError::InvalidOpcode)
}
}
}
generated by cgit v1.1 at 2024-12-22 20:02:00 +0000