SPK+ - will most probably be for speaker.
DM, BOOT0 maybe interesting, not really sure offhand unless you take a look and see what signals are coming out of either.. GND will be ground.
Whats on the other side of the board?
What SoC is it using under the heatsink? (the big block above PZ1)
My usual method will be to check what the SoC is, and try see where the UART pins lead.
This camera - right?
https://www.eufylife.com/products/variant/indoor-cam-2k/T84001W1See if you can find some firmware that we can look at also. That will give more clues. It's probably ARM based.
What does the flash branding say? I think its a Winbond, but not 100% from the photo. (its left, above the TEAN E120339 writing)
At a guess, its likely SPI flash, as I only see 8 pins, but a better shot of the model number would help.