kumquat-buildroot/board/radxa/rockpi-4
..
extlinux.conf
genimage.cfg
post-build.sh
readme.txt

RADXA ROCK_PI_4
================
https://rockpi.org/rockpi4

ROCK Pi 4 is a Single Board Computer (SBC) from radxa. This guide is valid
for the below models:
- ROCK PI 4 Model A
- ROCK PI 4 Model B
- ROCK PI 4 Model C

Build:
======
  $ make rock_pi_4_defconfig
  $ make

Files created in output directory
=================================

output/images

├── bl31.elf
├── boot.vfat
├── extlinux
├── idbloader.img
├── Image
├── rk3399-rock-pi-4.dtb
├── rootfs.ext2
├── rootfs.ext4 -> rootfs.ext2
├── rootfs.tar
├── sdcard.img
├── u-boot.bin
└── u-boot.itb

Creating bootable SD card:
==========================

Simply invoke (as root)

sudo dd if=output/images/sdcard.img of=/dev/sdX && sync

Where X is your SD card device.

Booting:
========

Serial console:
---------------
RockPi4 has a 40-pin GPIO header. The pin layout is as follows:

pin 6:  gnd
pin 8:  tx
pin 10: rx

Baudrate for this board is 1500000.

Login:
------
Enter 'root' as login user, and the prompt is ready.

Wiki link:
https://wiki.amarulasolutions.com/bsp/rockchip/rk3399/rock-pi-4.html