Major refactor of codebase

include/mm/pmm.h

@@ -0,0 +1,13 @@
+#include <stdbool.h>
+#include <stdint.h>
+
+#define BLOCK_SIZE 4096
+
+typedef struct free_page_t {
+    struct free_page_t *next;
+    uint8_t _padding[4088];
+} __attribute((packed)) free_page_t;
+
+void pmm_init(void);
+uint64_t *pmm_alloc();
+void pmm_free(uint64_t *addr);