Lab1 folder added

lab1/Makefile

@@ -0,0 +1,14 @@
+HEADERS = simulator.h
+
+default: simulator
+
+simulator.o: simulator.c $(HEADERS)
+	gcc -c simulator.c -o simulator.o -ggdb -std=c99
+
+simulator: simulator.o
+	gcc simulator.o -o simulator -ggdb -std=c99
+
+clean:
+	-rm -f simulator.o
+	-rm -f simulator
+	-rm -f *.out mdump.txt

lab1/README.md

@@ -0,0 +1,13 @@
+MIPS Simulator
+==============
+
+A simulator for the MIPS like Instruction Set, that translates machine code created from the assembler, and then executes the machine instructions. Each instruction goes through a Fetch, Decode, Execute, Memory and Writeback stage of processing.
+
+# Build
+    $ make
+
+# RUN add.out assembler output file
+    $ ./simulator add.out
+
+
+

lab1/mipsInstructionMap.h

@@ -0,0 +1,35 @@
+/*
+ *
+ * mipsInstructionMap.h
+ * 
+ * Defines instructions as a hex value for comparison
+ *
+ * Modified by Masab Ahmad
+ *
+ */
+
+// R-Type Instructions
+#define RTYPEOP 0x0
+#define ADD	0x20
+#define SUB	0x21
+#define AND	0x24
+#define OR	0x25
+#define SLL	0x0
+#define SLT	0x2A
+#define SRL	0x2
+#define JR	0x8
+
+// I-Type Instructions
+#define LW	0x23
+#define SW	0x2B
+#define ANDI	0xC
+#define ORI	0xD
+#define LUI	0xF
+#define BEQ	0x4
+#define BNE	0x5
+#define SLTI	0xA
+#define ADDI	0x8
+
+// J-Type Instructions
+#define J	0x2
+#define JAL	0x3

lab1/simulator.c

@@ -0,0 +1,296 @@
+/*
+ * riscy-uconn simulator.c
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "simulator.h"
+#include "mipsInstructionMap.h"
+
+int debug = 0;
+
+int main(int argc, char *argv[]) {
+
+  if (argc != 2) {
+    printf("Incorrect number of arguments\n");
+    exit(1);
+  }
+  else {
+    // Open Input file
+    FILE *fp;
+    fp = fopen(argv[1], "r");
+
+    // Call initialize function for registers and instruction/data memory
+    initialize(fp);
+
+    // Process one instruction at a time
+    process_instructions();
+
+    printf("\n Printing Output Registers \n");
+
+    // Output registers
+    rdump();
+
+    // Output Memory
+    mdump();
+
+    // Dealloc .data
+    free(memory);
+    memory = NULL;
+
+    // Close File
+    fclose (fp);
+    return 0;
+  }
+}
+
+// Function to take in instruciton to parse
+void process_instructions() {
+
+   int terminate = 0;
+   // Cycle PC
+   int instruction_counter = 0;
+
+   while(terminate != 1)
+   {
+     // set terminate flag when SLL $0, $0, 0 (aka NOOP) is executed
+     if (memory[pc/4] == 0)
+        terminate = 1;
+
+     //Fetch Instruction
+     unsigned int instruction_fetch;
+     instruction_fetch = fetch();
+     if(debug==1)
+        printf("\n IMEM ADDR:%d instruction 0x%08x", pc/4, instruction_fetch);
+     instruction_counter++;
+
+     // Decode Instruction
+     struct Registers decode_out;
+     decode_out = decode(instruction_fetch);
+
+     // Execute Instruction
+     struct Registers alu_out;
+     alu_out = execute(decode_out);
+
+     // Memory Stage
+     struct Registers mem_out;
+     mem_out = memory_stage(alu_out);
+
+     // Write Back Stage
+     write_back_stage(mem_out);
+   }//while pc loop
+   printf("\n TOTAL INSTRUCTIONS EXECUTED: %d", instruction_counter);
+} //process_instruction
+
+// Advance PC
+void advance_pc(int step) {
+  pc += step;
+}
+
+unsigned int fetch() {
+  unsigned int inst = 0;
+  return inst = memory[pc/4];
+}
+
+struct Registers decode(unsigned int instruction_fetch) {
+  struct Registers reg_temp;
+
+  // your code for decode phase goes here.
+
+  return reg_temp;
+}
+
+
+struct Registers execute(struct Registers decode_out)
+{
+   // your code for execute phase goes here.
+
+   return decode_out;
+}
+
+
+struct Registers memory_stage(struct Registers alu_out)
+{
+  // your code for memory phase goes here.
+
+  return alu_out;
+}
+
+void write_back_stage(struct Registers mem_out)
+{
+   // your code for write back phase goes here.
+
+} // WB Done
+
+
+// Output reigsters
+void rdump()
+{
+    printf("$0      $zero    0x%08x\n", registers[0]);
+    printf("$1      $at      0x%08x\n", registers[1]);
+    printf("$2      $v0      0x%08x\n", registers[2]);
+    printf("$3      $v1      0x%08x\n", registers[3]);
+    printf("$4      $a0      0x%08x\n", registers[4]);
+    printf("$5      $a1      0x%08x\n", registers[5]);
+    printf("$6      $a2      0x%08x\n", registers[6]);
+    printf("$7      $a3      0x%08x\n", registers[7]);
+    printf("$8      $t0      0x%08x\n", registers[8]);
+    printf("$9      $t1      0x%08x\n", registers[9]);
+    printf("$10     $t2      0x%08x\n", registers[10]);
+    printf("$11     $t3      0x%08x\n", registers[11]);
+    printf("$12     $t4      0x%08x\n", registers[12]);
+    printf("$13     $t5      0x%08x\n", registers[13]);
+    printf("$14     $t6      0x%08x\n", registers[14]);
+    printf("$15     $t7      0x%08x\n", registers[15]);
+    printf("$16     $s0      0x%08x\n", registers[16]);
+    printf("$17     $s1      0x%08x\n", registers[17]);
+    printf("$18     $s2      0x%08x\n", registers[18]);
+    printf("$19     $s3      0x%08x\n", registers[19]);
+    printf("$20     $s4      0x%08x\n", registers[20]);
+    printf("$21     $s5      0x%08x\n", registers[21]);
+    printf("$22     $s6      0x%08x\n", registers[22]);
+    printf("$23     $s7      0x%08x\n", registers[23]);
+    printf("$24     $t8      0x%08x\n", registers[24]);
+    printf("$25     $t9      0x%08x\n", registers[25]);
+    printf("$26     $k0      0x%08x\n", registers[26]);
+    printf("$27     $k1      0x%08x\n", registers[27]);
+    printf("$28     $gp      0x%08x\n", registers[28]);
+    printf("$29     $sp      0x%08x\n", registers[29]);
+    printf("$30     $fp      0x%08x\n", registers[30]);
+    printf("$31     $ra      0x%08x\n", registers[31]);
+
+    printf("  --> pc  0x%08x\n", pc);
+}
+
+// Output Memory
+void mdump()
+{
+    FILE *fptr;
+    fptr = fopen("mdump.txt","w");
+    int i = 0;
+    for(i=0;i<16384;i++)
+    {
+        fprintf(fptr,"\n Memory[%d] = %d",i,memory[i]);
+    }
+}
+
+void initialize(FILE *fp)
+{
+    if (fp == NULL)
+    {
+      printf("Error opening input file.\n");
+      exit(1);
+    }
+
+    // Initialize registers values' to 0x0
+    for (int i = 0; i < 32; i++)
+      registers[i] = 0x0;
+
+    printf("\n Initialized Registers \n");
+
+    // Malloc memory
+    memory  = (int *)malloc(16384 * sizeof(int));
+    if (memory == NULL)
+    {
+      printf("Not enough memory. Aborting..\n");
+      exit(1);
+    }
+
+    // Initialize 'memory' array to -1
+    for (int i = 0; i < 16384; i++)
+    {
+      memory[i] = -1;
+    }
+
+    printf("\n Initialized Memory \n");
+
+    // Initialize variables for parsing
+    char line[MAX_LENGTH+2];
+    char *p;
+    int i = 0, line_num = 0;
+    //int line_num = 0, i = 0, data_line = 0;
+
+    // Copy .text section to memory, breaks at nop
+    while (fgets(line, MAX_LENGTH+2, fp) != NULL)
+    {
+      line_num++;
+
+      // Remove '\n' from 'line'
+      p = strchr(line, '\n');
+      if (p != NULL)
+        *p = '\0';
+
+      memory[i] = getDec(line);
+      //printf("\n %d",memory[i]);
+
+      if (strcmp(line, "11111111111111111111111111111111") == 0)
+      {
+        memory[i] = 0;
+        i = 0x800;
+        break;
+      }
+      else
+        i++;
+    }
+
+    int j = 2048; //Data Memory Starts at 2048
+    for(j=i;j<16384;j++)
+    {
+      memory[j] = 2;
+      //printf("\n %d",memory[i]);
+    }
+
+    printf("\n Instructions Read, Memory Offset: %d\n", line_num);
+
+    // Seek fp to first instruction in .data
+    char data[MAX_LENGTH+2];
+    int bytes = 33 * line_num;
+    fseek(fp, bytes, SEEK_SET);
+
+    // Copy .data section to memory
+    while (fgets(line, MAX_LENGTH+2, fp) != NULL)
+    {
+      // Remove '\n' from 'line'
+      p = strchr(line, '\n');
+      if (p != NULL)
+        *p = '\0';
+
+      memory[i] = getDec(line);
+      printf("\n Data: %d %d",i,memory[i]);
+      i++;
+    }
+
+    printf("\n Data put in Memory \n");
+}
+
+// Convert a binary string to a decimal value
+int getDec(char *bin)
+{
+    int  b, k, m, n;
+    int  len, sum = 0;
+
+    // Length - 1 to accomodate for null terminator
+    len = strlen(bin) - 1;
+
+    // Iterate the string
+    for(k = 0; k <= len; k++)
+    {
+        // Convert char to numeric value
+        n = (bin[k] - '0');
+
+        // Check the character is binary
+        if ((n > 1) || (n < 0))
+        {
+            return 0;
+        }
+
+        for(b = 1, m = len; m > k; m--)
+            b *= 2;
+
+        // sum it up
+        sum = sum + n * b;
+    }
+    return sum;
+}
+