activate buses

Mount /boot:

	mkdir /boot

	mount /dev/mmcblk0p1 /boot
	
	
UART:

	make menuconfig, System configuration-extra arguments add --uart
	
	dtoverlay=uart1,txd1_pin=40,rxd1_pin=41
	
	dtoverlay=uart_swap
	
	gpio=40,41=a5


I2C:

	make busybox-menuconfig, in Linux Module Utilities add modprobe and more.

	make linux-menuconfig, in device drivers-i2c support <M> I2C device interface and in I2C Hardware Bus support <M> Broadcom BCM2835 I2C controller.

	make menuconfig, System configuration-extra arguments add --i2c

	modprobe i2c-bcm2708

	modprobe i2c-dev


SPI:

	make busybox-menuconfig, in Linux Module Utilities add modprobe and more.

	make menuconfig, System configuration-extra arguments add --spi

	modprobe spi-bcm2835