raspbian lite download from: https://www.raspberrypi.org/software/operating-systems/
install with: https://www.raspberrypi.org/software/
apt-get update
apt-get upgrade
rasbpi-config
	- enable ssh
	- wlan localization cz
	- connect to wifi
hash wifi password: https://unix.stackexchange.com/questions/278946/hiding-passwords-in-wpa-supplicant-conf-with-wpa-eap-and-mschap-v2
install pigpio: http://abyz.me.uk/rpi/pigpio/download.html
	- apt-get got version 71
	- then from github master 78
add rpi github account ssh key
update git config for the repository only
create new github repo branch "raspberry"
install ntp on rpi
	- ntp and ntpdate
	- https://knowledge.broadcom.com/external/article/152937/how-to-force-sync-with-ntp-server.html
	- https://www.maketecheasier.com/sync-linux-time-with-ntp-server/
	- https://www.vmware.com/support/vcm/doc/help/vcm-57/Content/ProvisioningHW/ProvHW_GS_Task_Provision_UNIX_ntp.htm
change timezone to local: https://linuxize.com/post/how-to-set-or-change-timezone-on-ubuntu-18-04/
made SD card backup: https://www.raspberrypi.org/documentation/linux/filesystem/backup.md
	- compressed and stored on Ubuntu SSD
	
removed ntp -> only ntpdate required for manual sync
disabled tickless kernel (nohz=off)
	- https://github.com/raspberrypi/linux/issues/750
	- https://stackoverflow.com/questions/9775042/how-nohz-on-affects-do-timer-in-linux-kernel
install cpupower: https://command-not-found.com/cpupower
set governor to performance (not permanent): https://wiki.archlinux.org/index.php/CPU_frequency_scaling
install chrony package
	- more precise than ntpdate: https://www.redhat.com/en/blog/combining-ptp-ntp-get-best-both-worlds
add performance governor to /etc/rc.local (make permanent on boot)
install linuxptp (ptp4l)
	- http://linuxptp.sourceforge.net/
	- https://tsn.readthedocs.io/timesync.html
install ptpd package
make separate installs directory in github directory for installs from source
	- pigpio, linuxptp
made SD card backup: https://www.raspberrypi.org/documentation/linux/filesystem/backup.md
	- compressed and stored on Ubuntu SSD

removed unnecessary pigpio managed by apt-get, keep only the install from source
apt-get update and apt-get upgrade
ran update scripts on pigpio and ptp4l
disabled Linux serial console with raspi-config -> GPIO pins can use primary UART
	- https://www.raspberrypi.org/documentation/configuration/uart.md
added disable-bt Device Tree overlay -> disabled bluetooth and made UART0 (ttyAMA0) primary
	- dtoverlay=disable-bt added to /boot/config.txt
	- sudo systemctl disable hciuart
	- https://www.raspberrypi.org/documentation/configuration/uart.md
made SD card backup: https://www.raspberrypi.org/documentation/linux/filesystem/backup.md
	- compressed and stored on Kali NTB

install jq package with apt-get
