Limitations of installing FortiGate-7000 firmware from the BIOS after a reboot
Installing or upgrading FortiGate-7000 firmware from the BIOS installs firmware on and resets the configuration of the primary FIM only. The other FIM and the FPMs will continue to operate with their current configuration and firmware build. The FortiGate-7000 system does not synchronize firmware upgrades performed from the BIOS.
See Installing firmware on individual FIMs and FPMs for detailed procedures for upgrading FortiGate-6000 firmware from the BIOS.