It was proposed many times ago, and it's not straightforward - indeed would need scavenging flashing code from multiboot.
#!/bin/sh export PATH=/usr/sbin:/usr/bin:/sbin:/bin initctl stop softupd ifconfig lo 127.0.0.1 netmask 255.0.0.0 up softupd --local --verbose --stdout --standalone & pid=$! flasher --local -f -k $1 sleep 1 kill $pid echo "Finished flashing."