+fifo_putone(struct fifo_buf* fbuf, u8_t data);
+
+size_t
+fifo_readone_async(struct fifo_buf* fbuf, u8_t* data);
+
+size_t
+fifo_readone(struct fifo_buf* fbuf, u8_t* data);
+
+void
+fifo_set_rdptr(struct fifo_buf* fbuf, size_t rdptr);
+
+void
+fifo_set_wrptr(struct fifo_buf* fbuf, size_t wrptr);