+
+Advanced ext4 filesystem features, like extents or journaling require some memory.
+However most of the memory expensive features could be disabled at compile time.
+Here is a brief summary for cortex-m4 processor:
+
+* .text: 20KB - only ext2 fs support , 50KB - full ext4 fs feature set
+* .data: 8KB - minimum 8 x 1KB block cache, 12KB - when journaling and extents are enabled
+* .stack: 2KB - is enough (not measured precisely)
+
+Blocks are allocated dynamically. Previous versions of library could work without
+malloc but from 1.0.0 dynamic memory allocation is required. However, block cache
+should not allocate more than CONFIG_BLOCK_DEV CACHE_SIZE.