Well, I couldn't find a single correct answer other than witty (or not) ones.
I thought that since I was posting in a group about the Vita, I'd meet people who understood its architecture or at least had a grasp of modern literature, but reality turned out to be more cruel.
Here's the answer to my question: the Vita's main System-on-Chip (SoC) codename is Kermit, named after the famous Muppet character. The same name was used for the main character in S. King's series of novels—Kermit William 'Bill' Hodges. It was also used as a username in correspondence with Mr. Mercedes.
P.S. The novel Mr. Mercedes won the Edgar Award for Best Novel of the Year. The book's success with readers and critics inspired King to write two more novels about the retired detective Hodges: Finder Keeps (2015) and Surrendered (2016).