Implement storedevs, prepare to port littlefs

kernel/util/util.h

@@ -6,4 +6,34 @@
 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
 #define LEN(X) (sizeof(X)/sizeof(X[0]))
 
+#define LL_APPEND(head, new) \
+  do { \
+    if ((head) != NULL) { \
+      typeof((head)) __tmp; \
+      (new)->next = NULL; \
+      __tmp = (head); \
+      while (__tmp->next != NULL) { \
+        __tmp = __tmp->next; \
+      } \
+      __tmp->next = (new); \
+    } else { \
+      (head) = (new); \
+    } \
+  } while(0)
+
+#define LL_REMOVE(head, ele) \
+  do { \
+    typeof((head)) __cur = (head); \
+    typeof((head)) __prev = NULL; \
+    while (__cur != (ele)) { \
+      __prev = __cur; \
+      __cur = __cur->next; \
+    } \
+    if (__prev != NULL) { \
+      __prev->next = __cur->next; \
+    } \
+  } while(0)
+
+char *util_get_filename(char *path);
+
 #endif // UTIL_UTIL_H_