...on an operating system you wrote yourself (or fully understand), on a chip you fabricated from a design you thoroughly understand

NAND to Tetris

http://www.cs.huji.ac.il/course/2006/nand2tet/

Better link: http://www1.idc.ac.il/tecs/

But yes, awesome book. :)

But who trusts you or me, anyways?

The compiler could've been compromised too, as said by Ken Thompson.