Ethereum on ARM. New Eth2.0 Raspberry pi 4 image for automatically joining Prylabs Onyx Eth2.0 testnet. Step-by-step guide for installing and activating a validator.
TL;DR: Flash your Raspberry Pi 4, plug in an ethernet cable, connect the SSD disk and power up the device to join the Eth2.0 Onyx testnet.
The image takes care of all the necessary steps to join the Eth2.0 Onyx testnet , from setting up the environment and formatting the SSD disk to installing and running the Ethereum Eth1.0 and Eth2.0 clients as well as starting the blockchains synchronization (for both Geth Eth1.0 Goerli  and Prysm  Eth2.0 Beacon Chain).
You will only need to create a validator account, send the deposit of 32 Goerli ETH to the Onyx contract and start the validator systemd service.
You will need and SSD to run the Ethereum clients (without an SSD drive there’s absolutely no chance of syncing the Ethereum blockchain). There are 2 options: