how to automatically start a PC using c

Question

hey guys, is there any way i can automatically turn a pc on without having to go to BIOS? ie from windows using a language or the like

Answer 1

Of course when the computer is powered off, no code will run, so the the answer to the title of your question is no. The actual body of your question seems to be a different question; what does the BIOS have to do with anything?

Technically is is possible without an external stimulus such as "wake-up on LAN" if your hardware and OS support the ACPI "wake-up on RTC alarm" feature. The RTC is battery-backed, and has an alarm feature that can trigger a wake-up.

However the issues/variable are: Hardware support, BIOS support, OS support, API support to access the protected RTC hardware resource in order to set an alarm in the first instance.

Answer 2

It sounds like you're asking how to call some sort of OS restart or shutdown feature (system call in UNIX/Linux, or I guess it would be a "service" in MS Windows).

In any event the details of how to start, restart or shutdown a system are platform specific and differ considerably from one OS to another ... and sometimes a bit among different hardware models and OS versions even within any given OS).

Answer 3

If you want to turn on a PC remotely (i.e. from another computer connected to the network), you can use "wake on lan" to do it. Here is a C implementation: http://www.gcd.org/sengoku/docs/wol.c I have not tested this C code. I use a script in Perl to switch PCs on which telnets into a router and tells the router to send the so-called magic packet.

"Wake on lan" is a feature of the network interface so it may or may not be present on your computer.

Answer 4

Note that many programs have already been written for this purpose.

See: Wake on LAN

Answer 5

No, there isn't. BIOS is essential for your Input-Output operations between Software and Hardware. Without a properly-setup BIOS, no hardware in your system will work at all.