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