init commit Comp architect Toua

ls8/cpu.c

@@ -3,6 +3,18 @@
 /**
  * Load the binary bytes from a .ls8 source file into a RAM array
  */
+
+unsigned char cpu_ram_read(struct cpu *cpu, unsigned char mem)
+{
+  return cpu->ram[mem];
+}
+
+void cpu_ram_write(struct cpu *cpu, unsigned char mem, unsigned char mdr)
+{
+  cpu->ram[mem] = mdr;
+}
+
+
 void cpu_load(struct cpu *cpu)
 {
   const int DATA_LEN = 6;
@@ -45,11 +57,30 @@ void alu(struct cpu *cpu, enum alu_op op, unsigned char regA, unsigned char regB
 void cpu_run(struct cpu *cpu)
 {
   int running = 1; // True until we get a HLT instruction
+  unsigned char IR, operandA, operandB;
 
   while (running) {
     // TODO
     // 1. Get the value of the current instruction (in address PC).
+    IR = cpu_ram_read(cpu, cpu->PC);
+    operandA = cpu_ram_read(cpu, cpu->PC+1);
+    operandB = cpu_ram_read(cpu, cpu->PC+1);
     // 2. switch() over it to decide on a course of action.
+    switch (IR) {
+      case LDI:
+        cpu->registers[operandA] = operandB;
+        cpu->PC+=3;
+        break;
+      case PRN:
+        printf("%d\n", cpu->registers[operandA]);
+        cpu->PC+=2;
+        break;
+      case HTL:
+        running = 0;
+        cpu->PC+=1;
+        break
+    } 
+
     // 3. Do whatever the instruction should do according to the spec.
     // 4. Move the PC to the next instruction.
   }
@@ -61,6 +92,11 @@ void cpu_run(struct cpu *cpu)
 void cpu_init(struct cpu *cpu)
 {
   // TODO: Initialize the PC and other special registers
+  cpu->PC = 0;
 
+
+
   // TODO: Zero registers and RAM
+  memset(cpu->ram, 0, sizeof cpu->ram);
+  memset(cpu->registers, 0, sizeof cpu->registers);
 }

ls8/cpu.h

@@ -5,8 +5,11 @@
 struct cpu {
   // TODO
   // PC
+  unsigned char PC;
   // registers (array)
+  unsigned char registers[6];
   // ram (array)
+  unsigned char ram[256];
 };
 
 // Instructions
@@ -15,6 +18,8 @@ struct cpu {
 // literals should be used.
 
 #define LDI  0b10000010
+#define PRN  0b01000111
+#define HTL  0b00000001
 // TODO: more instructions here. These can be used in cpu_run().
 
 // Function declarations