this is my very first question in StackOverflow... So please bare with me. Thank you. I am working on some automation project, where I have some test scripts in bootable USB. To run this automation, I need the PC to boot from USB BUT... the PC BIOS are set to boot from 1st internal HDD, 2nd PXE and 3rd USB. Currently, I have to press F9 to bring me into boot selection menu, arrow-down-key to select the USB, and enter-key to boot from it. Keep in mind that I am not able to change the BIOS setting and the "boot selection menu" are most of the time not the same. Question : Is there a way I can bypass this manual process ?
I tried using microcontroller sending F9 signal at boot (to go into boot selection menu), wait for 20seconds, then send arrow-down signal 2 times, then send "enter" signal to select USB. BUT some PC took more than 20seconds (failed as timing already out) and some PC got more selections (CD/DVD) and arrow-down x2 no longer work.