initramfs

• How to unpack/uncompress and repack/re-compress an initial ramdisk (initrd/initramfs) boot image file?

# 因为会解压到当前目录，使用空目录避免清理

mkdir -p /tmp/initrd

cd /tmp/initrd

# GZIP

zcat < /boot/initramfs-lts | cpio -idmv

find . | cpio -o -c -R root:root | gzip -9 > /boot/new.img

# xz/LZMA

xz -dc < /boot/initramfs-lts | cpio -idmv

find . 2>/dev/null | cpio -o -c -R root:root | xz -9 --format=lzma > /boot/new.img