Vuk

asm/sctest.ls8

@@ -0,0 +1,86 @@
+# Code to test the Sprint Challenge
+#
+# Expected output:
+# 1
+# 4
+# 5
+
+10000010 # LDI R0,10
+00000000
+00001010
+10000010 # LDI R1,20
+00000001
+00010100
+10000010 # LDI R2,TEST1
+00000010
+00010011
+10100111 # CMP R0,R1
+00000000
+00000001
+01010101 # JEQ R2
+00000010
+10000010 # LDI R3,1
+00000011
+00000001
+01000111 # PRN R3
+00000011
+# TEST1 (address 19):
+10000010 # LDI R2,TEST2
+00000010
+00100000
+10100111 # CMP R0,R1
+00000000
+00000001
+01010110 # JNE R2
+00000010
+10000010 # LDI R3,2
+00000011
+00000010
+01000111 # PRN R3
+00000011
+# TEST2 (address 32):
+10000010 # LDI R1,10
+00000001
+00001010
+10000010 # LDI R2,TEST3
+00000010
+00110000
+10100111 # CMP R0,R1
+00000000
+00000001
+01010101 # JEQ R2
+00000010
+10000010 # LDI R3,3
+00000011
+00000011
+01000111 # PRN R3
+00000011
+# TEST3 (address 48):
+10000010 # LDI R2,TEST4
+00000010
+00111101
+10100111 # CMP R0,R1
+00000000
+00000001
+01010110 # JNE R2
+00000010
+10000010 # LDI R3,4
+00000011
+00000100
+01000111 # PRN R3
+00000011
+# TEST4 (address 61):
+10000010 # LDI R3,5
+00000011
+00000101
+01000111 # PRN R3
+00000011
+10000010 # LDI R2,TEST5
+00000010
+01001001
+01010100 # JMP R2
+00000010
+01000111 # PRN R3
+00000011
+# TEST5 (address 73):
+00000001 # HLT

ls8/cpu.c

@@ -1,42 +1,95 @@
 #include "cpu.h"
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
 
 #define DATA_LEN 6
 
+
+unsigned char cpu_ram_read(struct cpu *cpu, unsigned char address)
+{
+  return cpu->ram[address];
+} 
+
+
+void cpu_ram_write(struct cpu *cpu, unsigned char address, unsigned char value)
+{
+  cpu->ram[address] = value;
+}
+
 /**
  * Load the binary bytes from a .ls8 source file into a RAM array
  */
-void cpu_load(struct cpu *cpu)
+
+void cpu_load(struct cpu *cpu, char *filename)
 {
-  char data[DATA_LEN] = {
-    // From print8.ls8
-    0b10000010, // LDI R0,8
-    0b00000000,
-    0b00001000,
-    0b01000111, // PRN R0
-    0b00000000,
-    0b00000001  // HLT
-  };
+  // char data[DATA_LEN] = {
+  //   // From print8.ls8
+  //   0b10000010, // LDI R0,8
+  //   0b00000000,
+  //   0b00001000,
+  //   0b01000111, // PRN R0
+  //   0b00000000,
+  //   0b00000001  // HLT
+  // };
 
-  int address = 0;
+  // int address = 0;
 
-  for (int i = 0; i < DATA_LEN; i++) {
-    cpu->ram[address++] = data[i];
-  }
+  // for (int i = 0; i < DATA_LEN; i++) {
+  //   cpu->ram[address++] = data[i];
+  // }
 
   // TODO: Replace this with something less hard-coded
+  FILE *fp = fopen(filename, "r");
+
+  if (fp == NULL) {
+    fprintf(stderr, "error opening file");
+    exit(2);
+  }
+
+  char line[8192];
+  int address = 0;
+
+
+  while (fgets(line, sizeof line, fp) != NULL) {
+
+    char *endptr;
+    unsigned char val = strtoul(line, &endptr, 2);
+
+    if (endptr == NULL) {
+      continue;
+    }
+
+
+    cpu->ram[address++] = val;
+  } 
+
+  fclose(fp);
+
+
 }
 
 /**
  * ALU
  */
 void alu(struct cpu *cpu, enum alu_op op, unsigned char regA, unsigned char regB)
 {
+
+  unsigned char firstValue = cpu->registers[regA];
+  unsigned char secondValue = cpu->registers[regB];
   switch (op) {
     case ALU_MUL:
       // TODO
+      cpu->registers[regA] = firstValue * secondValue;
+      break;
+    case ALU_ADD:
+      cpu->registers[regA] = firstValue + secondValue;
       break;
-
     // TODO: implement more ALU ops
+    case ALU_CMP:
+      if (firstValue == secondValue) {
+        cpu->FL = 0;
+      }
   }
 }
 
@@ -48,11 +101,70 @@ void cpu_run(struct cpu *cpu)
   int running = 1; // True until we get a HLT instruction
 
   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 = cpu_ram_read(cpu, cpu->pc+1);
+    unsigned char operandB = cpu_ram_read(cpu, cpu->pc+2);
     // 3. Get the appropriate value(s) of the operands following this instruction
     // 4. switch() over it to decide on a course of action.
+    switch(ir) {
+
+      case LDI:
+        cpu->registers[operandA] = operandB;
+        cpu->pc += 3;
+        break;
+      case HLT:
+        running = 0;
+        break;
+      case PRN:
+        printf("%d\n", cpu->registers[operandA]);
+        cpu->pc += 2;
+        break;
+      case MUL:
+        alu(cpu, ALU_MUL, operandA, operandB);
+        cpu->pc += 3;
+        break;
+      case ADD:
+        alu(cpu, ALU_ADD, operandA, operandB);
+        cpu->pc += 3;
+        break;
+      //Jumps to the address stored in the given register
+      case CMP:
+        alu(cpu, ALU_CMP, operandA, operandB);
+        cpu->pc += 3;
+        break;
+      case JMP:
+        cpu->pc = cpu->registers[operandA];
+        cpu->pc += 2;
+        break;
+      ///IF equal flag is set to true jump to the address in the register
+      case JEQ:
+        if (cpu->FL == 1) {
+          cpu->pc = cpu->registers[operandA];
+          cpu->FL = 0;
+        } else {
+          cpu->pc += 2;
+          cpu->FL = 0;
+        }
+        break;
+      case JNE:
+        if ((cpu->FL & 1) != 1) {
+          cpu->pc = cpu->registers[operandA];
+          cpu->FL = 0;
+        } else {
+          cpu->pc += 2;
+          cpu->FL = 0;
+        }
+        break;
+      default:
+        running = 0;
+        // break;
+    }
+
+
     // 5. Do whatever the instruction should do according to the spec.
     // 6. Move the PC to the next instruction.
   }
@@ -63,5 +175,13 @@ void cpu_run(struct cpu *cpu)
  */
 void cpu_init(struct cpu *cpu)
 {
+  cpu->pc = 0;
+  cpu->FL = 0b00000000;
+  memset(cpu->ram, 0, sizeof(cpu->ram));
+  memset(cpu->registers, 0, sizeof(cpu->registers));
+  cpu->registers[7] = 0xF4;
   // TODO: Initialize the PC and other special registers
+  ///Initalize our cpu, start ram and registers and pc to 0 memset() might help
 }
+
+

ls8/cpu.h

@@ -4,14 +4,21 @@
 // Holds all information about the CPU
 struct cpu {
   // TODO
-  // PC
+  //Flag
+  int FL;
+  // PC - keeps the index of the currently executing instruction
+  unsigned char pc;
   // registers (array)
+  unsigned char registers[8];
   // ram (array)
+  unsigned char ram[256];
 };
 
 // ALU operations
 enum alu_op {
-	ALU_MUL
+	ALU_MUL,
+  ALU_ADD,
+  ALU_CMP
 	// Add more here
 };
 
@@ -23,11 +30,19 @@ enum alu_op {
 #define LDI  0b10000010
 #define HLT  0b00000001
 #define PRN  0b01000111
+#define MUL  0b10100010
+#define ADD  0b10100000
+#define CMP  0b10100111
+#define JMP  0b01010100
+#define JEQ  0b01010101
+#define JNE  0b01010110
+
+
 // TODO: more instructions here. These can be used in cpu_run().
 
 // Function declarations
 
-extern void cpu_load(struct cpu *cpu);
+extern void cpu_load(struct cpu *cpu, char *filename);
 extern void cpu_init(struct cpu *cpu);
 extern void cpu_run(struct cpu *cpu);
 

ls8/ls8.c

@@ -4,13 +4,25 @@
 /**
  * Main
  */
-int main(void)
+int main(int argc, char **argv)
 {
+
+
+
   struct cpu cpu;
 
+
+  if (argc != 2) {
+    fprintf(stderr, "pass in a valid file only");
+    return(1);
+  }
+
+  //Gets the filename that was passed in from the command line
+  char *filename = argv[1];
+
   cpu_init(&cpu);
-  cpu_load(&cpu);
+  cpu_load(&cpu, filename);
   cpu_run(&cpu);
 
   return 0;
-}
+}