Barbara Hunter

asm/README.md

@@ -25,3 +25,5 @@ node asm source.asm
 ## TODO
 
 * Port this to Python
+
+<!-- comment -->

ls8/cpu.c

@@ -1,7 +1,9 @@
 #include "cpu.h"
+#include <stdio.h>
+#include <string.h>
 
 #define DATA_LEN 6
-
+#define LR 7
 /**
  * Load the binary bytes from a .ls8 source file into a RAM array
  */
@@ -50,18 +52,71 @@ void cpu_run(struct cpu *cpu)
   while (running) {
     // TODO
     // 1. Get the value of the current instruction (in address PC).
+    unsigned char IR = cpu_ram_read(cpu, cpu->pc);
     // 2. Figure out how many operands this next instruction requires
+
+    unsigned char operandA = 0;
+    unsigned char operandB = 0;
+    unsigned int numOp = IR >> 6;
+
     // 3. Get the appropriate value(s) of the operands following this instruction
+
+    if (numOp == 2)
+    {
+      unsigned char operandA = cpu_ram_read(cpu, (cpu->pc + 1) & 0xff);
+      unsigned char operandB = cpu_ram_read(cpu, (cpu->pc + 2) & 0xff);
+    }
+
     // 4. switch() over it to decide on a course of action.
+
+    switch (IR)
+    {
+    case LDI:
+    printf("%d\n", cpu->reg[operandB]);
+      cpu->reg[operandA] = operandB;
+      cpu->pc += 2;
+      printf("%d\n", cpu->reg[operandB]);
+      break;
+    case PRN:
+      cpu->pc += 2;
+      printf("%d\n", cpu->reg[operandA]);
+      break;
+    case HLT:
+      running = 0;
+      break;
+    default:
+      printf("Error");
+      break;
     // 5. Do whatever the instruction should do according to the spec.
     // 6. Move the PC to the next instruction.
   }
 }
 
+// ram functions
+unsigned char cpu_ram_read(struct cpu *cpu, unsigned char index)
+{
+  return cpu->ram[index];
+}
+
+void cpu_ram_write(struct cpu *cpu, unsigned mar, unsigned char mdr)
+{
+  cpu->ram[mar] = mdr;
+}
+
 /**
  * Initialize a CPU struct
  */
 void cpu_init(struct cpu *cpu)
 {
   // TODO: Initialize the PC and other special registers
+for (int i = 0; i <= 6; i++)
+  {
+    cpu->reg[i] = 0;
+  }
+
+  cpu->reg[7] = 0;
+  cpu->pc = 0;
+
+  // set everything in ram to 0
+  memset(cpu->ram, 0, sizeof cpu->ram);
 }

ls8/cpu.h

@@ -4,9 +4,12 @@
 // Holds all information about the CPU
 struct cpu {
   // TODO
+  unsigned int PC;
   // PC
   // registers (array)
+  unsigned char reg[8];
   // ram (array)
+  unsigned char ram[256];
 };
 
 // ALU operations
@@ -20,9 +23,12 @@ enum alu_op {
 // These use binary literals. If these aren't available with your compiler, hex
 // literals should be used.
 
-#define LDI  0b10000010
-#define HLT  0b00000001
-#define PRN  0b01000111
+#define LDI 0b10000010
+#define HLT 0b00000001
+#define PRN 0b01000111
+
+// Stack instructions
+
 // TODO: more instructions here. These can be used in cpu_run().
 
 // Function declarations

ls8/ls8.c

@@ -4,12 +4,17 @@
 /**
  * Main
  */
-int main(void)
+int main(int argc, char **argv)
 {
   struct cpu cpu;
+  if (argc != 2)
+  {
+    fprintf(stderr, "incorrect input\n");
+    return 1;
+  }
 
   cpu_init(&cpu);
-  cpu_load(&cpu);
+  cpu_load(&cpu, argv[1]);
   cpu_run(&cpu);
 
   return 0;