Extract Cramfs

Check the endianness of the Cramfs file:

file cramfs

This is a big endian file. Convert cramfs file to little endian file cramfs_le using cramfsswap.

cramfsswap cramfs cramfs_le

Extract the little endian file cramfs_le to folder fs using fsck.cramfs.

sudo fsck.cramfs --extract=fs cramfs_le

Create Cramfs

Use mkfs.cramfs to create Cramfs file system from the contents of folder fs.To create a little endian file system:

sudo mkfs.cramfs fs cramfs_new

For big endian Cramfs file system:

sudo mkfs.cramfs -N big fs cramfs_new