added structure definition for linked list kmalloc

Author: chrisdedman

include/memory.h

@@ -7,11 +7,37 @@
 extern "C"
 {
 #endif
+    /**
+     * @enum block_state
+     * @brief Enumeration of block states in the memory allocator.
+     *
+     * This enum defines the possible states of a memory block in the
+     * kernel memory allocator.
+     */
+    enum block_state {
+        BLOCK_FREE = 0, /**< Block is free and available for allocation. */
+        BLOCK_USED      /**< Block is currently allocated and in use. */
+    };
 
-    void  kmalloc_init(void *start, void *limit);
-    void* kmalloc(size_t size);
-    size_t kmalloc_remaining(void);
+    /**
+     * @brief Header structure for memory blocks in the allocator.
+     *
+     * Each allocated or free block in the kernel memory allocator is
+     * preceded by a header that contains metadata about the block.
+     */
+    struct header {
+        size_t           size;     /**< Size of the memory block (excluding header). */
+        enum block_state state;    /**< State of the block (free or used). */
+        struct header    *next;    /**< Pointer to the next block in the linked list. */
+        struct header    *prev;    /**< Pointer to the previous block in the linked list. */
+    };
 
+    struct header *kmalloc_get_head(void);
+
+    void   kmalloc_init(void *start, void *limit);
+    void*  kmalloc(size_t size);
+    void   kfree(void *block);
+    int    kmalloc_test(void);
 #ifdef __cplusplus
 }
 #endif