#Letter#
#Device Tree
(SoC and board)#
#Basic
"initialization"
C file
+
basic header
files#
#Timer
driver#
#IRQ controller
driver#
#Serial port
driver#
#arch/arm/boot/dts/#
#arch/arm/mach-<foo>/#
#drivers/clocksource/#
#drivers/irqchip/#
#drivers/tty/serial/#
#earlyprintk
support#
#arch/arm/include/debug#
#Pin muxing
control#
#GPIO#
#Clocks#
#drivers/pinctrl/#
#drivers/clk/#
#drivers/gpio/#
#Step 1#
#Step 2#