How to write BIOS program that connects to the internet?

I am aware that there are programs out there like lojack for laptops that get installed on the BIOS, but I'm still a little confused. When reading about lojack, it seems to me that they can't fully located the laptop's location until the user开发者_Python百科 logs in and tries to access the internet. So I'm thinking that it's a BIOS application so that it wouldn't matter if the thief reformats the HD.

So my question is, does anyone have any ideas of how an internet enables BIOS application would be written. I'm not looking for full answers -- just ideas or resources to get started. For example, is such a thing written in assembly? Once one such app is written, how does it get transfered to the BIOS. Does the BIOS program itself recognize that there is an internet connection (when the thief logs on to the OS). Or upon logon, does additional processes get spawned? Are there any resources/websites that anyone can direct me too?

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You didn't mention whether you were interested in legacy BIOS or EFI BIOS, but I would mention that with EFI there is the capability of writing EFI applications. See Intel Press:

Harnessing the UEFI Shell

The EFI Application toolkit comes with a complete TCP/IP network stack:
http://www.intel.com/technology/efi/toolkit_overview.htm

More at tianocore.org

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Regarding "LoJack"-style solutions, one of the providers of this technology is Absolute Software's Computrace product.

Basically there are 3 components: 1) a software component that runs in the OS; 2) a BIOS component which is baked into the system BIOS (accomplished via Absolute working with the PC vendor); 3) servers at Absolute software that talk to the PC.

For more information on how it works visit:
http://www.absolute.com/en/company/Computrace-Persistence.aspx

(see especially the demo video on this site)

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To learn something about BIOS, one good source is coreboot.org. It is an open source BIOS (or firmware) and support some physical machines.

Legacy BIOS is written in assembly language, but new generations, such as UEFI or coreboot, are written mostly in C language. BIOS program is stored in the ROM, and executed by the CPU automatically.

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The BIOS program itself does not access the internet or perform any of the advertised functions. The LoJack addition to the BIOS firmware is a file copying/patching utility - at boot up it can check the harddrive for a copy of Windows and proceed to silently install/repair the LoJack service if it has been removed. The service itself includes several measures to lower it's profile and prevent itself from being disabled (similar to how many trojans and malware run several processes that each restore the other if one is disabled or killed).

The LoJack BIOS program can't do anything if a unsupported operating system (like Linux) is installed after the harddrive is wiped.