diff --git a/kernel/cpu.c b/kernel/cpu.c
index cb043f6..1098dd3 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1,6 +1,7 @@
 #include "cpu.h"
 #include "serial.h"
 #include "terminal.h"
+#include "utils.h"
 
 void cpuid(uint32_t function, uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx) {
     asm volatile (
diff --git a/kernel/display.c b/kernel/display.c
new file mode 100644
index 0000000..e69de29
diff --git a/kernel/display.h b/kernel/display.h
new file mode 100644
index 0000000..e69de29
diff --git a/kernel/framebuffer.c b/kernel/framebuffer.c
new file mode 100644
index 0000000..e69de29
diff --git a/kernel/framebuffer.h b/kernel/framebuffer.h
new file mode 100644
index 0000000..e69de29
diff --git a/kernel/gui.c b/kernel/gui.c
new file mode 100644
index 0000000..e69de29
diff --git a/kernel/gui.h b/kernel/gui.h
new file mode 100644
index 0000000..e69de29
diff --git a/kernel/io.h b/kernel/io.h
index 9e82fcb..aaaee3a 100644
--- a/kernel/io.h
+++ b/kernel/io.h
@@ -1,6 +1,8 @@
 #ifndef IO_H
 #define IO_H
 
+#include <stdint.h>
+
 static inline void outb(uint16_t port, uint8_t val) {
     asm volatile ("outb %0, %1" : : "a"(val), "Nd"(port));
 }
diff --git a/kernel/isr.c b/kernel/isr.c
index f23a850..636a189 100644
--- a/kernel/isr.c
+++ b/kernel/isr.c
@@ -2,13 +2,22 @@
 #include "serial.h"
 #include "isr.h"
 #include "io.h"
+#include "utils.h"
 
 static isr_callback_t interrupt_handlers[MAX_INTERRUPTS] = { 0 };
 
 void isr_handler(uint32_t int_num, uint32_t err_code) {
     terminal_write("Interrupt occurred: ");
+
+    print_hex(int_num);
+    terminal_write("\n");
+
     serial_write("INT triggered\n");
 
+    terminal_write("Error code: ");
+    print_hex(err_code);
+    terminal_write("\n");
+
     if (interrupt_handlers[int_num]) {
         interrupt_handlers[int_num]();  // Call registered handler
     } else {
diff --git a/kernel/keyboard.c b/kernel/keyboard.c
index 187dc77..d590b73 100644
--- a/kernel/keyboard.c
+++ b/kernel/keyboard.c
@@ -28,7 +28,7 @@ void keyboard_callback() {
         return;
 
     char c = scancode_map[scancode];
-    if (c && buffer_index < sizeof(key_buffer)) {
+    if (c && buffer_index < sizeof(key_buffer) - 1) {
         key_buffer[buffer_index++] = c;
         terminal_putchar(c); // Echo to terminal (optional)
     }
diff --git a/kernel/kmain.c b/kernel/kmain.c
index 07d0cd5..ec3b932 100644
--- a/kernel/kmain.c
+++ b/kernel/kmain.c
@@ -8,6 +8,9 @@
 #include "memmap.h"
 #include "gdt.h"
 #include "cpu.h"
+#include "kmalloc.h"
+#include "timer.h"
+#include "utils.h"
 
 #define LPT1 0x378
 
diff --git a/kernel/memmap.c b/kernel/memmap.c
index 001f95c..53cbacf 100644
--- a/kernel/memmap.c
+++ b/kernel/memmap.c
@@ -1,14 +1,21 @@
 #include "memmap.h"
 
 uint32_t get_memory_map(memory_map_entry_t *map, uint32_t max_entries) {
-    // Fill with dummy values for now
-    map[0].base_addr = 0x00000000;
-    map[0].length = 0x0009FC00;
-    map[0].type = 1;
+    uint32_t count = 0;
 
-    map[1].base_addr = 0x00100000;
-    map[1].length = 0x1FF00000;
-    map[1].type = 1;
+    if (max_entries >= 1) {
+        map[count].base_addr = 0x00000000;
+        map[count].length = 0x0009FC00;
+        map[count].type = 1;
+        count++;
+    }
 
-    return 2; // 2 regions
-}
+    if (max_entries >= 2) {
+        map[count].base_addr = 0x00100000;
+        map[count].length = 0x1FF00000;
+        map[count].type = 1;
+        count++;
+    }
+
+    return count;
+}
\ No newline at end of file
diff --git a/kernel/serial.c b/kernel/serial.c
index f1036c8..703f3cd 100644
--- a/kernel/serial.c
+++ b/kernel/serial.c
@@ -1,5 +1,6 @@
 #include "io.h"
 #include "serial.h"
+#include <stdint.h>
 
 #define COM1 0x3F8
 #define COM2 0x2F8
diff --git a/kernel/shell.c b/kernel/shell.c
index c634d95..ee445f1 100644
--- a/kernel/shell.c
+++ b/kernel/shell.c
@@ -17,7 +17,7 @@ void execute(char *input) {
 void shell_loop()
 {
     char input[256];
-    int index = 0;
+    size_t index = 0;
     char c;
 
     while (1)
diff --git a/kernel/terminal.c b/kernel/terminal.c
index c649803..180b12a 100644
--- a/kernel/terminal.c
+++ b/kernel/terminal.c
@@ -96,7 +96,7 @@ void terminal_clear(void) {
     update_cursor();
 }
 
-static void update_cursor() {
+void update_cursor() {
     uint16_t pos = cursor_y * VGA_WIDTH + cursor_x;
 
     outb(0x3D4, 0x0F);
diff --git a/kernel/timer.c b/kernel/timer.c
index afbe5b8..03e539c 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -2,6 +2,7 @@
 #include "io.h"
 #include "isr.h"
 #include "terminal.h"
+#include "stdio.h"
 
 static uint32_t tick = 0;
 
diff --git a/kernel/types.c b/kernel/types.c
new file mode 100644
index 0000000..6936871
--- /dev/null
+++ b/kernel/types.c
@@ -0,0 +1,9 @@
+#include "types.h"
+
+// Example: Basic memory helper (unnecessary if libc exists)
+void *memset(void *dest, int value, size_t len) {
+    unsigned char *ptr = (unsigned char *)dest;
+    while (len-- > 0)
+        *ptr++ = (unsigned char)value;
+    return dest;
+}
diff --git a/kernel/types.h b/kernel/types.h
new file mode 100644
index 0000000..32fc7ff
--- /dev/null
+++ b/kernel/types.h
@@ -0,0 +1,62 @@
+#ifndef TYPES_H
+#define TYPES_H
+
+// ----------------------------
+// Fixed-width integer types
+// ----------------------------
+typedef unsigned char      uint8_t;
+typedef signed char        int8_t;
+typedef unsigned short     uint16_t;
+typedef signed short       int16_t;
+typedef unsigned int       uint32_t;
+typedef signed int         int32_t;
+typedef unsigned long long uint64_t;
+typedef signed long long   int64_t;
+
+// ----------------------------
+// Boolean & NULL definitions
+// ----------------------------
+#ifndef __cplusplus
+typedef enum { false = 0, true = 1 } bool;
+#endif
+
+#ifndef NULL
+#define NULL ((void*)0)
+#endif
+
+// ----------------------------
+// OS subsystem types
+// ----------------------------
+typedef uint32_t size_t;
+typedef int32_t  ssize_t;
+
+typedef uint32_t phys_addr_t; // Physical address
+typedef uint32_t virt_addr_t; // Virtual address
+
+typedef uint32_t pid_t;       // Process ID
+typedef uint32_t tid_t;       // Thread ID
+
+// ----------------------------
+// Bitfield & utility macros
+// ----------------------------
+#define BIT(n) (1U << (n))
+#define BITS(m, n) (((1U << ((n) - (m) + 1)) - 1) << (m))
+
+// Align value to next multiple of alignment
+#define ALIGN_UP(val, align) (((val) + ((align)-1)) & ~((align)-1))
+#define ALIGN_DOWN(val, align) ((val) & ~((align)-1))
+
+// ----------------------------
+// Attributes for structures
+// ----------------------------
+#define PACKED      __attribute__((packed))
+#define ALIGN(x)    __attribute__((aligned(x)))
+
+// ----------------------------
+// Likely/unlikely branch hints
+// (for future optimization use)
+// ----------------------------
+#define likely(x)   __builtin_expect(!!(x), 1)
+#define unlikely(x) __builtin_expect(!!(x), 0)
+
+#endif // TYPES_H
diff --git a/kernel/utils.c b/kernel/utils.c
index 06d4494..04dd14c 100644
--- a/kernel/utils.c
+++ b/kernel/utils.c
@@ -1,4 +1,6 @@
 #include "utils.h"
+#include "serial.h"
+#include "terminal.h"
 
 static void reverse(char* str, int len) {
     int start = 0;