mostly improvements to malloc

kernel/kmalloc.c

@@ -1,6 +1,8 @@
 #include "kmalloc.h"
 #include "terminal.h"  // Optional: for debug output
 
+#define HEAP_END 0xC0100000
+
 static uint32_t current_heap = 0;
 
 // Initialize the allocator with a starting heap address
@@ -32,7 +34,18 @@ void* kmalloc_aligned(size_t size, uint32_t alignment) {
         current_heap = (current_heap + alignment) & ~(alignment - 1);
     }
 
+    if (current_heap + size > HEAP_END) {
+        terminal_write("kmalloc_aligned: Out of memory!\n");
+        return 0;
+    }
+
     void* addr = (void*)current_heap;
     current_heap += size;
     return addr;
 }
+
+void kfree(void* ptr) {
+    // In a bump allocator, we cannot free individual blocks.
+    // We can reset the allocator to the initial state.
+    current_heap = 0; // Reset the heap pointer
+}