Revision as of 09:41, 6 February 2018 (view source) Fcorthay (Talk | contribs) (→‎Backup) ← Older edit		Revision as of 11:02, 19 March 2019 (view source) Fcorthay (Talk | contribs) (→‎Prepare an SD card) Newer edit →
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	This wiki bases on the console version of Raspbian.		This wiki bases on the console version of Raspbian.
−	== Prepare an SD card ==	+	== Operating system ==
−	On a Linux computer, download it:	+	A [https://www.raspberrypi.org/downloads/raspbian/ disk image]
−	su	+	can be downloaded and copied to the SD card
−	cd /tmp	+	with the help of [https://etcher.io/ Etcher].
−	wget https://downloads.raspberrypi.org/raspbian_lite_latest -O raspbian-lite.zip	+	unzip ~/Downloads/etcher-1.1.2-linux-x86_64.zip -d /tmp/
−	sha1sum raspbian-lite.zip	+	/tmp/etcher-*.AppImage &
−	unzip raspbian-lite.zip.zip	+
−	mv *-raspbian-*-lite.img raspbian-lite.img	+
−	Insert a card reader with the SD card you wish to use and write the image:	+	Place the SD card on the board and power it.
−	fdisk -l	+	Attach a keyboard and a screen and wait for the boot process to terminate.
−	RPI_DISK='/dev/sdb'	+	Login as <code>pi</code> with username <code>raspberry</code>.
−	umount $RPI_DISK*	+	raspi-config
−	ls -lh raspbian-lite.img | sed -e 's/.*root/Copying/' | sed -e 's/G.*rasp/G file rasp/'	+	sudo su
−	dd if=raspbian-lite.img of=$RPI_DISK status=progress conv=fsync && \	+	passwd
−	aplay /usr/share/sounds/alsa/Front_Center.wav	+	apt update
−	eject $RPI_DISK	+	apt upgrade
−	Unplug the SD card reader and plug it in again.	+	With <code>raspi-config</code>, one can:
−	Find the mount point:	+	* change the keyboard layout
−	df -h | grep $RPI_DISK	+	* edit the host name
−	RPI_DISK_MOUNTPOINT='/media/francois/boot'	+	* enable <code>ssh</code> (from <code>Interfacing Options</code>)
		+	* disable predictable interface names (keep to <code>eth0</code> and <code>wlan0</code>)
		+	* set the wi-fi region
−	Remove <code>init=/usr/lib/raspi-config/init_resize.sh</code> from:	+	Enable root SSH by changing in <code>/etc/ssh/sshd_config</code>:
−	nano -w $RPI_DISK_MOUNTPOINT/cmdline.txt	+	PermitRootLogin yes
−	Eject the SD card reader:	+	Disable the [https://en.wikipedia.org/wiki/Bluetooth Bluetooth] related services:
−	eject $RPI_DISK	+	systemctl disable hciuart.service
		+	systemctl disable bluetooth.service
		+
		+	Disable loading the Bluetooth kernel modules by adding in <code>/boot/config.txt</code>:
		+	# Disable Bluetooth
		+	dtoverlay=pi3-disable-bt
	== Change root settings ==		== Change root settings ==

---

Revision as of 11:02, 19 March 2019

The xPL protocol is light enough to run on simple machines such as the Raspberry Pi.

Install Raspbian

Several distributions are available for the Raspberry Pi. This wiki bases on the console version of Raspbian.

Operating system

A disk image can be downloaded and copied to the SD card with the help of Etcher.

unzip ~/Downloads/etcher-1.1.2-linux-x86_64.zip -d /tmp/
/tmp/etcher-*.AppImage &

Place the SD card on the board and power it. Attach a keyboard and a screen and wait for the boot process to terminate. Login as pi with username raspberry.

raspi-config
sudo su
passwd
apt update
apt upgrade

With raspi-config, one can:

• change the keyboard layout
• edit the host name
• enable ssh (from Interfacing Options)
• disable predictable interface names (keep to eth0 and wlan0)
• set the wi-fi region

Enable root SSH by changing in /etc/ssh/sshd_config:

PermitRootLogin yes

Disable the Bluetooth related services:

systemctl disable hciuart.service
systemctl disable bluetooth.service

Disable loading the Bluetooth kernel modules by adding in /boot/config.txt:

# Disable Bluetooth
dtoverlay=pi3-disable-bt

Change root settings

Insert the SD card in the Raspberry Pi and boot it.

sudo su
passwd
apt update
apt upgrade

Setup aliases:

nano .bashrc
source .bashrc

Specify what to do with pageUp/Down keys:

nano /etc/inputrc

Allow ssh:

nano /etc/ssh/sshd_config
# change: PermitRootLogin yes
service ssh restart

Locales

Set the regional parameters:

raspi-config

Then edit ~.bashrc and add:

# Locales
export LC_ALL=C

Swap partition

Add a 1 GB swap partition

cfdisk /dev/mmcblk0
swaplabel -L swap /dev/mmcblk0p3

Edit /etc/fstab and add:

LABEL=swap    none    swap    sw    0 0

Remove the default swapfile:

update-rc.d -f dphys-swapfile remove
swapoff -a
rm /var/swap

Reboot and check:

swapon -s

Ethernet

Check the Ethernet connection:

ifconfig | grep 'inet '
ping -c 4 google.com

Change host name:

raspi-config

Give a static IP address:

nano /etc/dhcpcd.conf

Add the following lines:

# Set a static IP address
interface eth0
static ip_address=192.168.1.18/24
static routers=192.168.1.1
static domain_name_servers=192.168.1.3

Restart the machine and re-enable SSH:

reboot
raspi-config
ifconfig | grep 'inet '

Set-up Apple FileProtocol (AFP) sharing:

apt install netatalk
nano /etc/netatalk/AppleVolumes.default

Programming tools

Install Perl documentation reader:

apt-get install perl-doc

Users

Removing the default user can close security gaps:

userdel -r pi

Add a data partition for the users' home

cfdisk /dev/mmcblk0
mke2fs -t ext4 -L data /dev/mmcblk0p4

Edit /etc/fstab and add:

LABEL=data    /home    ext4    defaults,noatime    0 1

Reboot the machine:

reboot
lsblk -o name,label,mountpoint

Add the control user:

useradd -m -g users -G users,dialout,audio -s /bin/bash control
passwd control

Backup

Zeroing unused blocks on the SD card should be better for later compression:

apt install secure-delete
lsblk -o name,label,mountpoint

Zero fill unused blocks of the data partition:

sfill -lzv /home/

Zero fill unused blocks of the system partition:

umount /home
sfill -lzv /

Zero the swap partition:

swapoff /dev/mmcblk0p3
dd if=/dev/zero of=/dev/mmcblk0p3
mkswap -L pi-swap /dev/mmcblk0p3

Stop the machine:

halt

Extract the SD card, insert it in a reader and plug it in a Linux PC.

Save the whole disk:

lsblk -o name,label,fstype,size,mountpoint
RPI_DISK='/dev/sdb'
RPI_BACKUP_FILE='/home/user/Desktop/rpi.img.bz2'
umount $RPI_DISK*
dd if=$RPI_DISK status=progress | bzip2 -9f >$RPI_BACKUP_FILE
ls -lh $RPI_BACKUP_FILE
eject $RPI_DISK

Restore the whole disk:

bunzip2 -dc $RPI_BACKUP_FILE | dd of=$RPI_DISK status=progress

Checks

CPU usage

Check CPU usage:

ps -eo pcpu,user,args | sort -k 1 -r | head -10
echo && ps -eo pcpu,user,args | grep -v ' 0.0 ' | grep -v '%CPU' | sort -k 1 -r | sed 's/[ ^I]\/.*\/perl//' | sed 's/.pl[ ^I].*/.pl/'

Process priorities

Check process priorities:

ps ax -o nice,pid,user,args | grep -v ' NI ' | sort

The lowest numbers correspond to the highest priorities.

Change the priority level of xPL devices:

ps ax -o nice,pid,user,args | grep -v ' grep ' | grep -i xpl-

USER='control'
NEW_LEVEL=-10
SYSTEM_IFS=$IFS; IFS=$'\n'; 
task_list=(`ps ax -o pid,user,args | grep -v ' grep ' | grep -i '/xpl-'`)
IFS=$SYSTEM_IFS
for item in "${task_list[@]}" ;  do
  task_id=`echo "${item}" | sed "s/$USER.*//"`
# echo $task_id
  renice $NEW_LEVEL -p $task_id >/dev/null
done
ps ax -o nice,pid,user,args | grep -v ' grep ' | grep -i xpl-

Links

Here some interesting pages for the installation process:

• create a robust Raspberry Pi setup for 24x7 operation
• removing automatic filesystem expansion at boot
• enabling root ssh
• setting a static IP address
• setting-up WiFi