preboot authentication

[CptAwesome]

Hy guys
I have a little project i need help with. i want to add an authentication to my pc that will run before the boot options and before i can choose to enter bios(authentication means either password or certain key presses). now i have done some research and got some recommendations but it didn't help me much. i just want to know a language (C or assembly maybe?) and more important what format should it have and where to insert it.

thanks in advanced

ps: a lot of people think i want this script(let's call it that) to run before bios. this is wrong i want bios to run it(the script) before boot options appear so noone can acces any of my os.

i just want a simple solution like
(pseudocot don't know what language needed? C ?!)
get input
if input != what expected
power off laptop

and then a simple modify to my bios so it will run this process before others..but this is my 3rd forum and i am losing hope that this thing that i considered so easy is even possible...

ps2:no funny business(hacking, cracking) here, just for my own security. a lot of people think i want this so i can write a low level virus!? that will lock people out of their pc. Nope!

i want to lock people out of my laptop. i want to write it for one chipset, one bios. it's for security because os passwords can be cracked and i figured that if you can't run anything before authentication you can't do anything.

[weaknessforcats]

Have you considered getting a laptop with facial recognition?

[CptAwesome]

not a viable option...

[weaknessforcats]

Then I recommend your put your laptop in a safe with a combination lock.

There is simply no way code can execute before the machine has booted far enough to support code. Like the input so you can enter your userid and password. Like outut so your screen is operating. Like memory is up an running so you can load your program, etc...

[Rabbit]

If the end goal is to prevent someone from accessing your data on the drive, can't you just encrypt the entire system drive? It would provide more security and would require that you enter a password before the OS can be loaded.

[CptAwesome]

i will consider that. the thing is that there are programs that do this but i though i might be able to do it myself instead of buying a program.

[CptAwesome]

i found this: Bios Interrupt Service Routine (ISR). any of you guys know something about it and if it might work this way?