Tips for spotting unannounced Pi boards in the kernel before the official word

I gave this a shot last autumn after reading about it somewhere, and my experiance matches yours more or less. Cloned the kernel tree onto my Pi 4, ran a grep through the dts folder, and found a board name I'd never heard of alongside a chip code I couldn't match to anything in the shops. Got properly excited for about a week. Then I checked the firmware repo like you suggested and found barely anything there, which shold have told me something. Six months later that board still hasn't turned up, so it's sitting in my notes folder as a maybe. The thing I'd add is that the pull request route is harder than it sounds for a casual watcher. My git skills are basic at best, and telling a meaningful merge apart from routine housekeeping commits took me longer than I expected. What actualy helped was just skimming the commit log once a fortnight with a cup of tea and noting anything with a model string in it. Low effort, no scripts, and I still caught the wireless controller change in one dts file before anyone was talking about it.

On the spare PSU and SD card point, I'd only half agree. I stockpiled for a launch that got delayed twice and ended up using the parts on something else. These days I just wait for the first proper stock alerts instead of prepping early.

Second reply nails it for me, the fortnightly skim is all you need. I did the same with a calendar reminder and last spring I spotted a new dts file with a model string that matched nothing on sale. Turned out to be real and it shipped a few months later, though I never got close to buying one because of the stock situation. My one extra habit is checking the dates on the commits themselves, since a file that gets touched again after the first merge usally means the board is still being actively worked on. Silent ones tend to stay silent.

I've been reading dts diffs since the days when the only way to know a board revision was real was to spot the changed GPIO pinout buried in a forum post somewhere. What catches people out is assuming the code name in the file matches the marketing name later. Half the time it doesn't. I've seen a board go through two or three name changes between the first dts file and the actual product page, so don't get attached to whatever string you grep out. Also worth a look, the overlays folder tends to get touched at the same time, and that sometimes hints at what add-ons they expect to work with it.

Same habit here, I do embedded contract work and I've had a script-free routine going for about three years now. I diff the dts folder against the previous release tag instead of the head, which filters out all the noise and leaves you with maybe a dozen files to eyeball each cycle. Caught a wireless combo change that way a full nine weeks before anything showed up in the shops. One thing I'm curious about with this Zero 3 W is whether the memory gets bumped alongside the radio, because that's usually the bit the dts file keeps quiet until launch week.