The Wyze Cam is a surprisingly inexpensive camera firmly lashed to the Wyze app, with no provision for ordinary IP camera streaming. It seems to be a generic camera with custom firmware and, unsurprisingly, one can commandeer the bootloader with different firmware from a MicroSD card, thereby adding missing functions and suppressing undesired actions.
Oddly, buying a genuine Wyze Cam directly from Wyze isn’t significantly more expensive than a generic from the usual eBay / Amazon sellers. Bonus: the legit camera arrives next week rather than in a month or two.
I found one of my few remaining 2 GB MicroSD cards, formatted it with a 512 MB (!) FAT32 partition (per the suggestions), set up the “custom firmware” bootloader, and installed it with no issues.
Installing the new firmware requires copying a directory tree, configuring the WiFi SSID and password in the usual wpa_supplicant, and rebooting. Works fine and, yeah, the camera now runs Linux.
I told the router to assign a known IP address to the camera’s MAC address, set up port forwarding for port 8554 to that IP address, put the camera against the storm window in the kitchen, and rebooted everything to get it working:
Unfortunately, while it works more-or-less well with browsers on the local network, it’s apparently inaccessible from outside. The router manages a DDNS name-to-IP mapping to make itself findable, the port is open, the forwarding seems correct, no image data arrives to browsers outside, and they eventually time out.
Changing to port 8080 doesn’t help, nor does using MJPEG instead of H264 encoding.
Even more unfortunately, the router doesn’t do hairpin connections (inside to outside to inside), so I can’t debug this mess from the Comfy Chair.
This is a placeholder for what I’ve done while I accumulate more knowledge …
The Smell of Molten Projects in the Morning 
When I need to do outside to inside debugging, I find using my phone as a hotspot for the outside connection to be handy for enabling comfy chair debugging.
If only we had phone coverage here!
The house sits on a local maximum, but it’s inside the Wappinger River Valley with all the phone towers outside the surrounding hills. The best possible 3G connection lets me do SMS and sometimes voice calls, but receiving actual data just doesn’t happen.
First world problem: yup.