I own a Ben NanoNote, at this point an ancient (2010) open-source, niche micro-laptop that ran a modification of OpenWrt. With a tiny keyboard and screen and all. It had no built-in anything, so the only way to get wireless connectivity on it was to buy one of these SDIO WLAN adapters. Had a lot of fun tinkering with that thing, maybe I should find it again...

https://en.wikipedia.org/wiki/Ben_NanoNote