root@OpenWrt:~# sysupgrade -h
Usage: /sbin/sysupgrade [options] <image file or URL>

Options:
        -d <delay>   add a delay before rebooting
        -f <config>  restore configuration from .tar.gz (file or url)
        -i           interactive mode
        -b / --create-backup <file>
                     create .tar.gz of files specified in sysupgrade.conf
                     then exit. Does not flash an image. If file is '-',
                     i.e. stdout, verbosity is set to 0 (i.e. quiet).
        -n           do not save configuration over reflash
        -q           less verbose
        -v           more verbose
        -h / --help  display this help

mtd -r write *.bin firmware

mtd -r write /tmp/