unmkinitramfs - extract content from an initramfs image 

syntax
$ unmkinitramfs [options] initramfs-file directory
 
To extract the /boot/initrd.img-5.14.0-8-amd64 file into the current working directory
$ unmkinitramfs /boot/initrd.img-5.14.0-8-amd64 .

To print verbose output
$ unmkinitramfs -v /boot/initrd.img-5.14.0-8-amd64 .



regards,
T.Dhanasekar