Implement basic layout of Gameboy Emulator

src/instruction.rs

@@ -0,0 +1,114 @@
+use super::cpu::{Cpu, RegisterPair};
+pub enum Instruction {
+    NOP
+}
+
+
+impl Instruction {
+    pub fn from_byte(cpu: &Cpu, byte: u8) -> Self {
+        if byte == 0xCB {
+            Self::from_prefixed_byte(cpu, byte)
+        } else {
+            Self::from_unprefixed_byte(cpu, byte)
+        }
+    }
+
+    fn from_prefixed_byte(cpu: &Cpu, byte: u8) -> Self {
+        // https://gb-archive.github.io/salvage/decoding_gbz80_opcodes/Decoding%20Gamboy%20Z80%20Opcodes.html
+        let x = (byte >> 6) & 0b00000011;
+        let y = (byte >> 3) & 0b00000111;
+        let z = byte & 0b00000111;
+        let p = y >> 1;
+        let q = y & 0b00000001;
+
+
+        unimplemented!()
+    }
+
+    fn from_unprefixed_byte(cpu: &Cpu, byte: u8) -> Self {
+        unimplemented!()
+    }
+}
+
+
+enum InstrRegisterPairs {
+    AF,
+    BC,
+    DE,
+    HL,
+    IncrementHL,
+    DecrementHL,
+}
+
+enum InstrRegisters {
+    A,
+    B,
+    C,
+    D,
+    E,
+    H,
+    L,
+    IndirectHL,
+}
+
+
+
+enum JumpCondition {
+    NotZero,
+    Zero,
+    NotCarry,
+    Carry,
+    Always,
+}
+
+struct Table;
+
+impl Table {
+    pub fn r(index: u8) -> InstrRegisters {
+        match index {
+            0 => InstrRegisters::B,
+            1 => InstrRegisters::C,
+            2 => InstrRegisters::D,
+            3 => InstrRegisters::E,
+            4 => InstrRegisters::H,
+            5 => InstrRegisters::L,
+            6 => InstrRegisters::IndirectHL,
+            7 => InstrRegisters::A,
+            _ => unreachable!("Index {} is out of bounds in r[]", index)
+        }
+    }
+
+    pub fn rp2(index: u8) -> RegisterPair {
+        match index {
+            0 => RegisterPair::BC,
+            1 => RegisterPair::DE,
+            2 => RegisterPair::HL,
+            3 => RegisterPair::AF,
+            _ => unreachable!("Index {} out of bounds in rp2[]", index)
+        }
+    }
+
+    pub fn rp(index: u8) -> RegisterPair {
+        match index {
+            0 => RegisterPair::BC,
+            1 => RegisterPair::DE,
+            2 => RegisterPair::HL,
+            3 => RegisterPair::AF,
+            _ => unreachable!("Index {} out of bounds in rp[]", index)
+        }
+    }
+
+    pub fn cc(index: u8) -> JumpCondition {
+        match index {
+            0 => JumpCondition::NotZero,
+            1 => JumpCondition::Zero,
+            2 => JumpCondition::NotCarry,
+            3 => JumpCondition::Carry,
+            _ => unreachable!("Index {} out of bounds in cc[]", index)
+        }
+    }
+
+    pub fn alu(index: u8) -> Instruction {
+        unimplemented!()
+    }
+}