fs/cromfs: Block length only needs to be uint16_t, not uint32_t. Add pading to node structure to assue that alignment is the same on all platforms. tools/gencromfs.c: Fix the target offset of the '.' hard link.

fs/cromfs/README.txt

@@ -249,6 +249,8 @@ configuration:
 
    Or the apps/examples/elf example if you like:
 
+   CONFIG_ELF=y
+   # CONFIG_BINFMT_DISABLE is not set
    CONFIG_EXAMPLES_ELF=y
    CONFIG_EXAMPLES_ELF_CROMFS=y
 

fs/cromfs/cromfs.h

@@ -120,6 +120,7 @@ struct cromfs_volume_s
 struct cromfs_node_s
 {
   uint16_t cn_mode;      /* File type, attributes, and access mode bits */
+  uint16_t cn_pad;        /* Not used */
   uint32_t cn_name;      /* Offset from the beginning of the volume header to the
                           * node name string.  NUL-terminated. */
   uint32_t cn_size;      /* Size of the uncompressed data (in bytes) */

fs/cromfs/fs_cromfs.c

@@ -71,9 +71,9 @@
 struct cromfs_file_s
 {
   FAR const struct cromfs_node_s *ff_node;  /* The open file node */
-  uint32_t ff_offset;                       /* Cached offset (zero means none) */
-  uint32_t ff_ulen;                         /* Length of uncompressed data in cache */
-  FAR uint8_t *ff_buffer;                   /* Decompression buffer */
+  uint32_t ff_offset;                       /* Cached block offset (zero means none) */
+  uint16_t ff_ulen;                         /* Length of decompressed data in cache */
+  FAR uint8_t *ff_buffer;                   /* Cached, decompressed data */
 };
 
 /* This is the form of the callback from cromfs_foreach_node(): */