Just wondering if a rasberi PI can be used to flash firmware to a P1 through DFU?
Wouldn’t see why not
You’ll want to look at doing it manually first by using the
dfu-util tool. See the firmware programming docs, specifically the “local DFU-UTIL” section.
Then you can automate this with the Particle firmware for the Pi.
I’m fairly certain that you can you can install dfu-util through installing po-util on Raspberry Pi.
po-util is a utility I created mainly for facilitating building with the local toolchain, but it also helps to properly install various dependencies for local development, manage libraries, update devices, and more.