I install FreeBSD on external hard disk,it works well until yesterday. I also had a linux system installed on an external hard disk. Yesterday I play steam games on linux, and then I want to use FreeBSD. But system cannot boot, linux system can't boot too. There's no external hard disk shown in BIOS boot option. What's wrong with it? I thought there's something wrong with my BIOS, so I adjusted some settings, after that BIOS disappear, I can't enter BIOS by pressing del.