I need a single board computer, on which I can easily learn bare-bone OS programming. In particular I need something like Raspberry PI, but:
- execution power must be circa about Raspberry Pi 3
- must have Wi-Fi and Bluetooth built on board
- must have very very good documentation (best if hardware was open source also)
- architecture should be multicore ARM or multicore Intel (generation does not matter)
- must also have possibility to use board to control external devices ( should have couple of GPIOs, some SPI communication etc.)