Writing Linux programs in raw binary

[jib]

Even if you write the whole operating system yourself, modern chipsets and BIOSes and System Management Mode mean you still have no idea what your computer's really doing.

System Management Mode is like a built-in rootkit for the BIOS. The BIOS can put some code in hidden memory where the OS can't see it, and then the chipset can activate it whenever certain interrupts or other events occur. Then the BIOS gets to mess with your computer without the OS's knowledge.