mostly improvements to malloc

kernel/print.c

@@ -1,6 +1,84 @@
 #include <stdio.h>
+#include <stdarg.h>
+#include "print.h"
 
-void print_string(const char *str)
-{
-    printf("%s", str);
+void my_putchar(char ch) {
+    // Write a single character to standard output
+    // In a freestanding environment, you might need to implement this differently
+    // For now, we will use the standard putchar for demonstration
+    // Replace this with your own implementation if needed
+    putchar(ch);
+}
+
+void print_string(const char *str) {
+    // Simple implementation to print a string
+    while (*str) {
+        my_putchar(*str++);
+    }
+}
+
+void my_printf(const char *format, ...) {
+    va_list args;
+    va_start(args, format);
+
+    while (*format) {
+        if (*format == '%') {
+            format++; // Move to the next character after '%'
+            switch (*format) {
+                case 's': { // String
+                    char *str = va_arg(args, char *);
+                    print_string(str);
+                    break;
+                }
+                case 'd': { // Integer
+                    int num = va_arg(args, int);
+                    char buffer[20]; // Buffer to hold the string representation
+                    snprintf(buffer, sizeof(buffer), "%d", num);
+                    print_string(buffer);
+                    break;
+                }
+                case 'c': { // Character
+                    char ch = (char)va_arg(args, int); // Promote char to int
+                    my_putchar(ch);
+                    break;
+                }
+                default:
+                    my_putchar('%'); // Print the '%' if no valid format specifier
+                    my_putchar(*format);
+                    break;
+            }
+        } else {
+            my_putchar(*format);
+        }
+        format++;
+    }
+
+    va_end(args);
+}
+
+
+void print_hex(unsigned int num) {
+    // Buffer to hold the hexadecimal representation
+    char buffer[9]; // 8 hex digits + null terminator
+    buffer[8] = '\0'; // Null-terminate the string
+
+    for (int i = 7; i >= 0; i--) {
+        int digit = num & 0xF; // Get the last 4 bits
+        buffer[i] = (digit < 10) ? (digit + '0') : (digit - 10 + 'A'); // Convert to hex character
+        num >>= 4; // Shift right by 4 bits
+    }
+
+    // Print the buffer, skipping leading zeros
+    int leading_zero = 1;
+    for (int i = 0; i < 8; i++) {
+        if (buffer[i] != '0') {
+            leading_zero = 0; // Found a non-zero digit
+        }
+        if (!leading_zero) {
+            my_putchar(buffer[i]);
+        }
+    }
+    if (leading_zero) {
+        my_putchar('0'); // If all were zeros, print a single '0'
+    }
 }