Implementing part of instructions

include/chip8.h

@@ -33,7 +33,6 @@ int font[FONT_SIZE][SPRITE_SIZE] = {
     {0xF0, 0x80, 0xF0, 0x80, 0x80}, // F
 };
 
-typedef uint16_t* stack;
 
 typedef struct Chip8{
     uint8_t RAM[MEM_SIZE];
@@ -43,8 +42,11 @@ typedef struct Chip8{
     uint8_t sound_timer;
     uint16_t I;
     uint16_t PC;
-    uint16_t SP;
+    int SP;
-    stack chip8_stack;
+    uint16_t* chip8_stack;
 }Chip8;
 
+void push(Chip8* chip8, uint16_t value);
+uint16_t pop(Chip8* chip8);
+
 #endif // __CHIP8_H__

include/instructions.h

@@ -24,7 +24,7 @@
     extern void __9XY0(Chip8 *chip8, uint8_t x, uint8_t y);
     extern void __ANNN(Chip8 *chip8, uint8_t nnn);
     extern void __BNNN(Chip8 *chip8, uint8_t nnn);
-    extern void __CXNN(Chip8 *chip8, uint8_t nn);
+    extern void __CXNN(Chip8 *chip8, uint8_t x, uint8_t nn);
     extern void __DXYN(Chip8 *chip8, uint8_t x, uint8_t y, uint8_t n);
     extern void __EX9E(Chip8 *chip8, uint8_t x);
     extern void __EXA1(Chip8 *chip8, uint8_t x);

src/chip8.c

@@ -12,11 +12,25 @@ Chip8 *init_cpu()
     chip8->sound_timer = 0x00;
     chip8->PC          = PROGRAM_ADDRESS;
     
-    chip8->chip8_stack = (stack)malloc(STACK_SIZE*sizeof(stack));
+    chip8->chip8_stack = (uint16_t*)malloc(STACK_SIZE*sizeof(uint16_t));
 
     return chip8;
 }
 
+void push(Chip8* chip8, uint16_t value)
+{
+    chip8->chip8_stack[chip8->SP++] = value;
+}
+
+uint16_t pop(Chip8* chip8)
+{
+    if(chip8->PC > 0){
+        return chip8->chip8_stack[--chip8->SP];
+    }else{
+        perror("Stack is empty!");
+    }
+}
+
 void start_cpu(Chip8 *chip8, uint8_t instructions[], int size)
 {
     int ram_index = 0;
@@ -69,7 +83,6 @@ void run(Chip8 *chip8, uint16_t instruction)
             
                 default:
                     panic("Invalid Instruction!");
-                    break;
             }
 
             break;
@@ -136,7 +149,6 @@ void run(Chip8 *chip8, uint16_t instruction)
 
                 default:
                     panic("Invalid Instruction!");
-                    break;
             }
 
             break;
@@ -168,7 +180,6 @@ void run(Chip8 *chip8, uint16_t instruction)
 
                 default:
                     panic("Invalid Instruction!");
-                    break;
             }
 
             break;
@@ -204,11 +215,13 @@ void run(Chip8 *chip8, uint16_t instruction)
                     break;
 
                 default:
-                    panic("Invalid Instruction!")
+                    panic("Invalid Instruction!");
-                    break;
             }
-            
+
             break;
+
+        default:
+            panic("Invalid Instruction!");
     }
 
 }

src/instructions.c

@@ -1,5 +1,8 @@
 #include "../include/instructions.h"
 
+#include <stdint.h>
+#include<stdlib.h>
+
 void __00E0(Chip8 *chip8)
 {
     for(int y = 0; y < DISPLAY_HEIGHT; y++)
@@ -13,107 +16,115 @@ void __00E0(Chip8 *chip8)
 
 void __00EE(Chip8 *chip8)
 {
-
+    chip8->PC = pop(chip8);
 }
 
 void __1NNN(Chip8 *chip8, uint8_t nnn)
 {
-
+    chip8->PC = nnn;
 }
 
 void __2NNN(Chip8 *chip8, uint8_t nnn)
 {
-
+    push(chip8, chip8->PC);
+    chip8->PC = nnn;
 }
 
 void __3XNN(Chip8 *chip8, uint8_t x, uint8_t nn)
 {
-
+    if(chip8->V[x] == nn){ chip8->PC += 2; }
 }
 
 void __4XNN(Chip8 *chip8, uint8_t x, uint8_t nn)
 {
-
+    if(chip8->V[x] != nn){ chip8->PC += 2; }
 }
 
 void __5XY0(Chip8 *chip8, uint8_t x, uint8_t y)
 {
-
+    if(chip8->V[x] == chip8->V[y]){ chip8->PC += 2; }
 }
 
 void __6XNN(Chip8 *chip8, uint8_t x, uint8_t nn)
 {
-
+    chip8->V[x] = nn;
 }
 
 void __7XNN(Chip8 *chip8, uint8_t x, uint8_t nn)
 {
-
+    chip8->V[x] += nn;
 }
 
 void __8XY0(Chip8 *chip8, uint8_t x, uint8_t y)
 {
-
+    chip8->V[x] = chip8->V[y];
 }
 
 void __8XY1(Chip8 *chip8, uint8_t x, uint8_t y)
 {
-
+    chip8->V[x] |= chip8->V[y];
 }
 
 void __8XY2(Chip8 *chip8, uint8_t x, uint8_t y)
 {
-
+    chip8->V[x] &= chip8->V[y];
 }
 
 void __8XY3(Chip8 *chip8, uint8_t x, uint8_t y)
 {
-
+    chip8->V[x] ^= chip8->V[y];
 }
 
 void __8XY4(Chip8 *chip8, uint8_t x, uint8_t y)
 {
-
+    chip8->V[x] += chip8->V[y];
 }
 
 void __8XY5(Chip8 *chip8, uint8_t x, uint8_t y)
 {
-
+    chip8->V[x] -= chip8->V[y];
 }
 
 void __8XY6(Chip8 *chip8, uint8_t x, uint8_t y)
 {
-
+    chip8->V[x] = chip8->V[x] >> 1;
 }
 
 void __8XY7(Chip8 *chip8, uint8_t x, uint8_t y)
 {
+    chip8->V[x] = chip8->V[y] - chip8->V[x];
 
+    if(chip8->V[y] >= chip8->V[x])
+    {
+        chip8->V[F] = 1;
+    }else{
+        chip8->V[F] = 0;
+    }
 }
 
 void __8XYE(Chip8 *chip8, uint8_t x, uint8_t y)
 {
-
+    chip8->V[x] = chip8->V[x] >> 1;
 }
 
 void __9XY0(Chip8 *chip8, uint8_t x, uint8_t y)
 {
-
+    if(chip8->V[x] != chip8->V[y]){ chip8->PC += 2; }
 }
 
 void __ANNN(Chip8 *chip8, uint8_t nnn)
 {
-
+    chip8->I = nnn;
 }
 
 void __BNNN(Chip8 *chip8, uint8_t nnn)
 {
-
+    chip8->PC = chip8->V[0] + nnn;
 }
 
-void __CXNN(Chip8 *chip8, uint8_t nn)
+void __CXNN(Chip8 *chip8, uint8_t x, uint8_t nn)
 {
-
+    chip8->V[x] = (rand() % 255) & nn;
 }
 
 void __DXYN(Chip8 *chip8, uint8_t x, uint8_t y, uint8_t n)
@@ -153,7 +164,7 @@ void __FX18(Chip8 *chip8, uint8_t x)
 
 void __FX1E(Chip8 *chip8, uint8_t x)
 {
-
+    chip8->I = chip8->V[x];
 }
 
 void __FX29(Chip8 *chip8, uint8_t x)

src/main.c

@@ -0,0 +1,50 @@
+#include "../include/chip8.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdnoreturn.h>
+#include <stdbool.h>
+
+noreturn void get_graphics()
+{
+    while(true)
+    {
+        
+    }
+}
+
+uint8_t load_rom(char* rom_path)
+{
+    FILE *file;
+    char* buffer;
+    long file_size;
+
+    file = fopen(rom_path,"rb");
+
+    if(file == NULL)
+    {
+        perror("File can not be opened!");
+        return 1;
+    }
+
+    fseek(file, 0, SEEK_END);
+    file_size = ftell(file);
+    rewind(file);
+
+    buffer = (char*)malloc(file_size*sizeof(char*));
+
+    size_t bytes_read = fread(buffer, 1, file_size, file);
+}
+
+int main(int argc, char** argv)
+{
+
+    if(argc > 1)
+    {
+        load_rom(argv[1]);
+    }else
+    {
+        perror("ROM not specified!");
+    }
+
+    return 0;
+}