reflect_os_rpi3

# NOTES:
# 1. serial0 is magically replaced to the right thing by the RPi bootloader.
#    /dev/serial0 won't exist unless you make it, so don't expected it in
#    userland.
# 2. If not using HDMI, remove console=tty1 and consoleblank=0
# 3. quiet skips printing kernel messages to the output and significantly
#    shortens boot time
console=tty1 console=serial0,115200 fbcon=scrollback:1024k root=/dev/mmcblk0p2 rootwait consoleblank=0 quiet