flash-kernel 3.90ubuntu3.18.04.2 (armhf binary) in ubuntu bionic

 flash-kernel is a script which will put the kernel and initramfs in
 the boot location of embedded devices that don't load the kernel and
 initramfs directly from /boot. flash-kernel supports devices that
 boot from flash memory (hence the name) as well as some devices that
 require a special boot image on the disk.