Add ram and rom, implement basic MOV functionality

1 files changed, 56 insertions, 10 deletions

diff --git a/src/core.rs b/src/core.rs
index 64f65fb..cd9dc1d 100644
--- a/src/core.rs
+++ b/src/core.rs
@@ -1,4 +1,4 @@
-use crate::ram::Ram;
+use crate::rom::Rom;
 use std::fmt;
 
 #[derive(Debug, Clone)]
@@ -13,6 +13,21 @@ pub enum Register {
     R7,
 }
 
+impl Register {
+    fn to_ram_offset(&self) -> u8 {
+        match self {
+            Register::R0 => RAM_OFFSET_R0,
+            Register::R1 => RAM_OFFSET_R1,
+            Register::R2 => RAM_OFFSET_R2,
+            Register::R3 => RAM_OFFSET_R3,
+            Register::R4 => RAM_OFFSET_R4,
+            Register::R5 => RAM_OFFSET_R5,
+            Register::R6 => RAM_OFFSET_R6,
+            Register::R7 => RAM_OFFSET_R7,
+        }
+    }
+}
+
 #[derive(Debug, Clone)]
 pub enum Operand {
     Acc,
@@ -31,6 +46,16 @@ pub struct Op {
     operand2: Option<Operand>,
 }
 
+const RAM_OFFSET_ACC: u8 = 0xE0;
+const RAM_OFFSET_R0: u8 = 0x00;
+const RAM_OFFSET_R1: u8 = 0x01;
+const RAM_OFFSET_R2: u8 = 0x02;
+const RAM_OFFSET_R3: u8 = 0x03;
+const RAM_OFFSET_R4: u8 = 0x04;
+const RAM_OFFSET_R5: u8 = 0x05;
+const RAM_OFFSET_R6: u8 = 0x06;
+const RAM_OFFSET_R7: u8 = 0x07;
+
 const OPCODE_NOP: u8 = 0x00;
 const OPCODE_MOV_A_DATA: u8 = 0x74;
 const OPCODE_MOV_DIRECT_DATA: u8 = 0x75;
@@ -95,19 +120,21 @@ impl Operand {
 
 pub struct Core {
     pc: u16,
-    ram: Ram,
+    ram: [u8; u8::max_value() as usize],
+    rom: Rom,
 }
 
 impl Core {
     ///
     /// Constructor
     ///
-    pub fn new_with_ram_from_hex(hex: String) -> Result<Self, String> {
-        let ram = match Ram::from_hex(hex) {
+    pub fn new_with_rom_from_hex(hex: String) -> Result<Self, String> {
+        let ram: [u8; u8::max_value() as usize] = [0; u8::max_value() as usize];
+        let rom = match Rom::from_hex(hex) {
             Ok(value) => value,
             Err(err_string) => return Err(err_string),
         };
-        Ok(Self { pc: 0, ram })
+        Ok(Self { pc: 0, ram, rom })
     }
 
     ///
@@ -123,7 +150,7 @@ impl Core {
     /// Get current instruction
     ///
     pub fn op(&self) -> Op {
-        let op = Isa8051Op::from_u8(self.ram.array[self.pc as usize]);
+        let op = Isa8051Op::from_u8(self.rom.array[self.pc as usize]);
         let operand1 = if let Some(operand) = op.operand1 {
             Some(self.map_operand(operand, 1))
         } else {
@@ -162,7 +189,7 @@ impl Core {
     fn exec(&mut self, op: Op) {
         match op.opcode {
             Isa8051Opcode::Nop => (),
-            Isa8051Opcode::Mov => (),
+            Isa8051Opcode::Mov => (self.mov(op.operand1.unwrap(), op.operand2.unwrap())),
             Isa8051Opcode::Illegal => (),
             Isa8051Opcode::Push => (),
             Isa8051Opcode::Pop => (),
@@ -179,6 +206,25 @@ impl Core {
         }
     }
 
+    fn mov(&mut self, o1: Operand, o2: Operand) {
+        let dest = match o1 {
+            Operand::Acc => RAM_OFFSET_ACC,
+            Operand::Direct(dir) => dir,
+            Operand::Indirect(r) => self.ram[r.to_ram_offset() as usize],
+            Operand::Register(r) => r.to_ram_offset(),
+            other => panic!("Mov: got incompatible first operand \"{:?}\"", other),
+        };
+        let value = match o2 {
+            Operand::Acc => RAM_OFFSET_ACC,
+            Operand::Direct(dir) => dir,
+            Operand::Indirect(r) => self.ram[r.to_ram_offset() as usize],
+            Operand::Data(r) => r,
+            Operand::Register(r) => r.to_ram_offset(),
+            other => panic!("Mov: got incompatible second operand \"{:?}\"", other),
+        };
+        self.ram[dest as usize] = value;
+    }
+
     fn sjmp(&mut self, reladdr: i8) {
         self.pc = (self.pc as i16 + i16::from(reladdr)) as u16;
     }
@@ -186,12 +232,12 @@ impl Core {
     fn map_operand(&self, operand: Isa8051Operand, offset: usize) -> Operand {
         match operand {
             Isa8051Operand::Acc => Operand::Acc,
-            Isa8051Operand::Direct => Operand::Direct(self.ram.array[(self.pc as usize + offset)]),
-            Isa8051Operand::Data => Operand::Data(self.ram.array[(self.pc as usize + offset)]),
+            Isa8051Operand::Direct => Operand::Direct(self.rom.array[(self.pc as usize + offset)]),
+            Isa8051Operand::Data => Operand::Data(self.rom.array[(self.pc as usize + offset)]),
             Isa8051Operand::Indirect(r) => Operand::Indirect(r),
             Isa8051Operand::Register(r) => Operand::Register(r),
             Isa8051Operand::Reladdr => {
-                Operand::Reladdr(self.ram.array[(self.pc as usize + offset)] as i8)
+                Operand::Reladdr(self.rom.array[(self.pc as usize + offset)] as i8)
             }
         }
     }