How to extract Cramfs files

Briefly, the Cramfs file is attached to the local system as a partition, and then it can be manipulated.

Suppose the file to be unzipped is Ljd2440-ii.cramfs
(1) Copy the Ljd2440-ii.cramfs to any directory
(2) Create two files in this directory:
mkdir ROMs
mkdir tmp
(3) Hook Ljd2440-ii.cramfs to the ROMs directory
Mount Ljd2440-ii.cramfs Roms–o Loop
(4) Compress the contents of the ROMs directory
TAR–CVF 1.tar ROMs
This will result in a 1.tar package at the top level of the ROMs directory.
60
(5) Unzip the package into the TMP directory.
Umount ROMs; unload mount
CD.; Go to the top level directory
MV 1.tar TMP;
CD tmp;
TAR–XVF 1.tar; Unzip the contents of the packaged root file system
RM 1.tar