[thastings]

If you need to enter the BIOS: bring up the terminal, and write `systemctl reboot --firmware-setup` This reboots systemd-powered systems to the UEFI menu. May not work on other init systems, but SteamOS is based on Arch with systemd.

[sedatk]

You can do the same on Windows with the command `shutdown /r /t 0 /fw`.

[jethro_tell]

Systemd systems can still have grub as a boot loader.

In that case, you can usually set the boot order with bootctl and reboot.

[jdiff]

Shouldn't matter what you have as a bootloader, by my understanding it should be communicating with the UEFI directly to pull it off and going over any bootloader's head.