Initial implementation of a freelist. blocks contain a header

kern/libkern/freelist.h

@@ -0,0 +1,34 @@
+#ifndef FREELIST_H
+#define FREELIST_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#define FL_FREE ((uint8_t)0x00)
+#define FL_USED ((uint8_t)0x01)
+
+typedef struct FreeListBlock {
+    struct FreeListBlock *next;
+    uint8_t               block_state;
+} FreeListBlock;
+
+typedef struct {
+    uintptr_t      start;
+    uintptr_t      end;
+    FreeListBlock *free;
+    size_t         size;
+    size_t         allocated;
+} FreeList;
+
+int    fl_init(FreeList *fl, uintptr_t start, uintptr_t end, size_t itemsize);
+int    fl_free(FreeList *fl, void *ptr);
+int    fl_is_managed(FreeList *fl, void *ptr);
+void  *fl_alloc(FreeList *fl);
+size_t fl_check(FreeList *fl);
+size_t fl_allocated(FreeList *fl);
+size_t fl_available(FreeList *fl);
+size_t fl_capacity(FreeList *fl);
+float  fl_utilization(FreeList *fl, size_t itemsize);
+
+#endif // FREELIST_H