TS-4900 Debian Sections
Debian is a community run Linux distribution. Debian provides tens of thousands of precompiled applications and services. This distribution is known for stability and large community providing support and documentation. This distribution does not include the same support as Yocto for the GPU. OpenGL ES, Gstreamer, or OpenCL are not supported in Debian. The framebuffer is supported by Debian, meaning 2D applications such as browsers and typical simple interface will still run well. Debian is also very well suited for headless applications.
We provide Debian Jessie (8) and Debian Stretch (9). We recommend new development uses use Debian Stretch (9) which will receive updates until June 2022, while Debian Jessie (8) will continue to receive security updates until April 2020.
Debian 10 - Buster
Debian 10 - Getting Started
The Debian images apply to the TS-4900, TS-7970, and TS-TPC-7990.
Image | Size | Kernel config | Description |
---|---|---|---|
debian-armhf-buster-latest.tar.bz2 | 1113 MB | ts4900_defconfig | Contains gcc, vim, X11, slim, and will autologin to an xfce4 desktop. |
Once installed the default user on either image is "root" with no password.
To prepare an SD card, use partitioning tools such as 'fdisk' 'cfdisk' or 'gparted' in linux to create a single linux partition on the SD card. Once the partition is created and formatted, extract the above tarball with:
# Assuming your SD card is /dev/sdc with one partition
mkfs.ext3 /dev/sdc1
mkdir /mnt/sd/
sudo mount /dev/sdc1 /mnt/sd/
sudo tar --numeric-owner -xjf debian-armhf-buster-latest.tar.bz2 -C /mnt/sd
sudo umount /mnt/sd
sync
Note: | The ext4 filesystem can be used instead of ext3, but it may require additional options. U-Boot does not support the 64bit addressing added as the default behavior in recent revisions of mkfs.ext4. If using e2fsprogs 1.43 or newer, the options "-O ^64bit,^metadata_csum" must be used with ext4 for proper compatibility. Older versions of e2fsprogs do not need these options passed nor are they needed for ext3. |
To rewrite the eMMC the unit must be booted to SD or any other media that is not eMMC. Once booted, run the following commands.:
mkfs.ext3 /dev/mmcblk2p1
mkdir /mnt/emmc
mount /dev/mmcblk2p1 /mnt/emmc
wget -qO- ftp://ftp.embeddedTS.com/ts-socket-macrocontrollers/ts-4900-linux/distributions/debian/debian-armhf-buster-latest.tar.bz2 | tar xj -C /mnt/emmc/
umount /mnt/emmc
sync
The same commands can be used to write a SATA drive by substituting /dev/mmcblk2p1 with /dev/sda1.
Debian 10 - Networking
The network in Debian is configured /etc/network/interfaces.d/. For complete documentation, see Debian's documentation here
Some common examples are shown below.
DHCP on eth0. Create the file: /etc/network/interfaces.d/eth0
auto eth0 allow-hotplug eth0 iface eth0 inet dhcp
Static IP on eth0. Create the file /etc/network/interfaces.d/eth0
auto eth0 iface eth0 inet static address 192.0.2.7/24 gateway 192.0.2.254
These will take effect on the next boot, or by restarting the networking service:
service networking restart
Debian 10 - WIFI Client
Wireless interfaces are also managed with configuration files in "/etc/network/interfaces.d/". For example, to connect as a client to a WPA network with DHCP. Note some or all of this software may already be installed on the target SBC.
Install wpa_supplicant:
apt-get update && apt-get install wpasupplicant -y
Run:
wpa_passphrase youressid yourpassword
This command will output information similar to:
network={ ssid="youressid" #psk="yourpassword" psk=151790fab3bf3a1751a269618491b54984e192aa19319fc667397d45ec8dee5b }
Use the hashed PSK in the specific network interfaces file for added security. Create the file:
/etc/network/interfaces.d/wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-ssid youressid
wpa-psk 151790fab3bf3a1751a269618491b54984e192aa19319fc667397d45ec8dee5b
To have this take effect immediately:
service networking restart
For more information on configuring Wi-Fi, see Debian's guide here.
Debian 10 - WIFI Access Point
First, hostapd needs to be installed in order to manage the access point on the device:
apt-get update && apt-get install hostapd -y
Note: | The install process will start an unconfigured hostapd process. This process must be killed and restarted before a new hostapd.conf will take effect. |
Edit /etc/hostapd/hostapd.conf to include the following lines:
interface=wlan0 driver=nl80211 ssid=YourAPName channel=1
Note: | Refer to the kernel's hostapd documentation for more wireless configuration options. |
To start the access point launch hostapd:
hostapd /etc/hostapd/hostapd.conf &
This will start up an access point that can be detected by WIFI clients. A DHCP server will likely be desired to assign IP addresses. Refer to Debian's documentation for more details on DHCP configuration.
Debian 10 - Installing New Software
Debian provides the apt-get system which allows management of pre-built applications. The apt tools require a network connection to the internet in order to automatically download and install new software. The update command will download a list of the current versions of pre-built packages.
apt-get update
A common example is installing Java runtime support for a system. Find the package name first with search, and then install it.
root@tsa38x:~# apt-cache search openjdk default-jdk - Standard Java or Java compatible Development Kit default-jdk-doc - Standard Java or Java compatible Development Kit (documentation) default-jdk-headless - Standard Java or Java compatible Development Kit (headless) default-jre - Standard Java or Java compatible Runtime default-jre-headless - Standard Java or Java compatible Runtime (headless) jtreg - Regression Test Harness for the OpenJDK platform libreoffice - office productivity suite (metapackage) openjdk-11-dbg - Java runtime based on OpenJDK (debugging symbols) openjdk-11-demo - Java runtime based on OpenJDK (demos and examples) openjdk-11-doc - OpenJDK Development Kit (JDK) documentation openjdk-11-jdk - OpenJDK Development Kit (JDK) openjdk-11-jdk-headless - OpenJDK Development Kit (JDK) (headless) openjdk-11-jre - OpenJDK Java runtime, using Hotspot JIT openjdk-11-jre-headless - OpenJDK Java runtime, using Hotspot JIT (headless) openjdk-11-jre-zero - Alternative JVM for OpenJDK, using Zero openjdk-11-source - OpenJDK Development Kit (JDK) source files uwsgi-app-integration-plugins - plugins for integration of uWSGI and application uwsgi-plugin-jvm-openjdk-11 - Java plugin for uWSGI (OpenJDK 11) uwsgi-plugin-jwsgi-openjdk-11 - JWSGI plugin for uWSGI (OpenJDK 11) uwsgi-plugin-ring-openjdk-11 - Closure/Ring plugin for uWSGI (OpenJDK 11) uwsgi-plugin-servlet-openjdk-11 - JWSGI plugin for uWSGI (OpenJDK 11) java-package - Utility for creating Java Debian packages
In this case, the wanted package will likely be the "openjdk-11-jre" package. Names of packages can be found on Debian's wiki pages or the packages site.
With the package name apt-get install can be used to install the prebuilt packages.
apt-get install openjdk-11-jre
# More than one package can be installed at a time.
apt-get install openjdk-11-jre nano vim mplayer
For more information on using apt-get refer to Debian's documentation here.
Debian 10 - Setting up SSH
Openssh is installed in our default Debian image, but by default openssh does not permit root logins, and requires a password to be set. Additionally, a host key is required if one hasn't already been created on the target board. To allow remote root login:
sed --in-place 's/#PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config
systemctl restart ssh.service
/bin/ls /etc/ssh/ssh_host*key >/dev/null 2>&1 || ssh-keygen -A
passwd root # Set any password
If you ssh to this system it will now support ssh as root.
Debian 10 - Starting Automatically
A systemd service can be created to start up headless applications. Create a file in /etc/systemd/system/yourapp.service
[Unit]
Description=Run an application on startup
[Service]
Type=simple
ExecStart=/usr/local/bin/your_app_or_script
[Install]
WantedBy=multi-user.target
If networking is a dependency add "After=network.target" in the Unit section. Once you have this file in place add it to startup with:
# Start the app on startup, but will not start it now
systemctl enable yourapp.service
# Start the app now, but doesn't change auto startup
systemctl start yourapp.service
Note: | See the systemd documentation for in depth documentation on services. |
Debian 10 - Cross Compiling
Debian only provides their cross compiler for their distribution. Our examples will set up a Docker for Debian to use for development. If using Debian 10 Buster directly, or through a VM then the docker usage can be skipped.
Create a file called "Dockerfile" with these contents:
FROM debian:buster
RUN dpkg --add-architecture armhf
RUN apt-get update && apt-get install -y \
autogen \
automake \
bash \
bc \
bison \
build-essential \
bzip2 \
ca-certificates \
ccache \
chrpath \
cpio \
curl \
diffstat \
fakeroot \
file \
flex \
gawk \
gcc-arm-linux-gnueabihf \
git \
gzip \
kmod \
libgpiod-dev:armhf \
libncursesw5-dev \
libssl-dev \
libtool \
locales \
lzop \
make \
multistrap \
ncurses-dev \
pkg-config \
python \
python3 \
python3-pip \
python3-pexpect \
qemu-user-static \
rsync \
socat \
runit \
texinfo \
u-boot-tools \
unzip \
vim \
wget \
xz-utils
# To make a more readable PS1 to show we are in the Docker
ENV debian_chroot debian_buster
RUN echo "PS1='\${debian_chroot}\\[\033[01;32m\\]@\\H\[\\033[00m\\]:\\[\\033[01;34m\\]\\w\\[\\033[00m\\]\\$ '" >> /etc/bash.bashrc
# Set up locales. Needed by yocto.
RUN sed -i -e 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen && \
echo 'LANG="en_US.UTF-8"'>/etc/default/locale && \
dpkg-reconfigure --frontend=noninteractive locales && \
update-locale LANG=en_US.UTF-8
ENV LC_ALL en_US.UTF-8
ENV LANG en_US.UTF-8
ENV LANGUAGE en_US.UTF-8
In the same directory as the file named "Dockerfile" run:
docker build --tag armhf-buster-toolchain .
When this has finished the docker can be used with:
docker run --rm -it --volume $(pwd):/work armhf-buster-toolchain bash
This will map the current directory to /work.
At this point the Debian Docker is ready to compile armhf binaries. For example, create a hello world in your home folder at ~/hello.c
#include <stdio.h>
int main(){
printf("Hello World\n");
}
To compile this enter the docker with:
docker run -it --volume $(pwd):/work armhf-buster-toolchain bash
# Then from the docker:
cd /work/
arm-linux-gnueabihf-gcc hello.c -o hello
Check "file hello" to verify the binary type:
user@host:~/$ file hello hello: ELF 32-bit LSB pie executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 3.2.0, BuildID[sha1]=8a8cee3341d3ef76ef6796f72d5722ae9d77c8ea, not stripped
This can also be used to develop against dynamic libraries from Debian. The armhf packages can be installed in the Docker. For example, to link against curl:
# Enter the Docker:
docker run -it --volume $(pwd):/work armhf-buster-toolchain bash
cd /work/
apt-get install libcurl4-openssl-dev:armhf
# Download curl's simple.c example
wget https://raw.githubusercontent.com/bagder/curl/master/docs/examples/simple.c
arm-linux-gnueabihf-gcc simple.c -o simple -lcurl
The "simple" binary is now built for armhf and links dynamically to curl.
This will only retain the armhf libcurl package until the docker is exited. To make the changes permanent, add the package to the Dockerfile and rerun:
docker build --tag armhf-buster-toolchain .
Debian 9 - Stretch
Debian 9 - Getting Started
We provide two images for Debian Stretch which apply to our TS-4900, TS-7970, and TS-TPC-7990. If you are unsure which image to pick, use the larger image which contains more development tools and drivers.
Image | Size | Kernel config | Description |
---|---|---|---|
debian-armhf-stretch-latest.tar.bz2 | 1279MB | ts4900_defconfig | Contains gcc, vim, X11, slim, and will autologin to an xfce4 desktop. |
debian-armhf-stretch-minimal-latest.tar.bz2 | 184MB | ts4900_tiny_defconfig | Stripped down Debian containing bare minimal hardware support, very limited peripheral support, and only the core debian packages. |
Once installed the default user on either image is "root" with no password.
To prepare an SD card, use partitioning tools such as 'fdisk' 'cfdisk' or 'gparted' in linux to create a single linux partition on the SD card. Once the partition is created and formatted, extract the above tarball with:
# Assuming your SD card is /dev/sdc with one partition
mkfs.ext3 /dev/sdc1
mkdir /mnt/sd/
sudo mount /dev/sdc1 /mnt/sd/
sudo tar --numeric-owner -xjf debian-armhf-stretch-latest.tar.bz2 -C /mnt/sd
sudo umount /mnt/sd
sync
Note: | The ext4 filesystem can be used instead of ext3, but it may require additional options. U-Boot does not support the 64bit addressing added as the default behavior in recent revisions of mkfs.ext4. If using e2fsprogs 1.43 or newer, the options "-O ^64bit,^metadata_csum" must be used with ext4 for proper compatibility. Older versions of e2fsprogs do not need these options passed nor are they needed for ext3. |
To rewrite the eMMC the unit must be booted to SD or any other media that is not eMMC. Once booted, run the following commands.:
mkfs.ext3 /dev/mmcblk2p1
mkdir /mnt/emmc
mount /dev/mmcblk2p1 /mnt/emmc
wget -qO- ftp://ftp.embeddedTS.com/ts-socket-macrocontrollers/ts-4900-linux/distributions/debian/debian-armhf-stretch-latest.tar.bz2 | tar xj -C /mnt/emmc/
umount /mnt/emmc
sync
The same commands can be used to write a SATA drive by substituting /dev/mmcblk2p1 with /dev/sda1.
Debian 9 - Networking
Debian can automatically set up the networking based on the contents of "/etc/network/interfaces.d/" files. For example, to enable DHCP for "eth0" by default on startup:
echo "auto eth0
iface eth0 inet dhcp" > /etc/network/interfaces.d/eth0
To set up a static IP:
echo "auto eth0
iface eth0 inet static
address 192.168.0.50
netmask 255.255.255.0
gateway 192.168.0.1" > /etc/network/interfaces.d/eth0
echo "nameserver 1.1.1.1" > /etc/resolv.conf
To make this take effect immediately for either option:
service networking restart
To configure other interfaces, replace "eth0" with the other network device name. Some interfaces may use predictable interface names. For example, the traditional name for an ethernet port might be "eth1", but some devices may use "enp1s0" for PCIe, or "enx00D069C0FFEE" (the MAC address appended) for USB ethernet interfaces. Run 'ifconfig -a' or 'ip a' to get a complete list of interfaces, including the ones that are not configured.
Debian 9 - WIFI Client =
Wireless interfaces are also managed with configuration files in "/etc/network/interfaces.d/". For example, to connect as a client to a WPA network with DHCP. Note some or all of this software may already be installed on the target SBC.
Install wpa_supplicant:
apt-get update && apt-get install wpasupplicant -y
Run:
wpa_passphrase youressid yourpassword
This command will output information similar to:
network={ ssid="youressid" #psk="yourpassword" psk=151790fab3bf3a1751a269618491b54984e192aa19319fc667397d45ec8dee5b }
Use the hashed PSK in the specific network interfaces file for added security. Create the file:
/etc/network/interfaces.d/wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-ssid youressid
wpa-psk 151790fab3bf3a1751a269618491b54984e192aa19319fc667397d45ec8dee5b
To have this take effect immediately:
service networking restart
For more information on configuring Wi-Fi, see Debian's guide here.
Debian 9 - WIFI Access Point
First, hostapd needs to be installed in order to manage the access point on the device:
apt-get update && apt-get install hostapd -y
Note: | The install process will start an unconfigured hostapd process. This process must be killed and restarted before a new hostapd.conf will take effect. |
Edit /etc/hostapd/hostapd.conf to include the following lines:
interface=wlan0 driver=nl80211 ssid=YourAPName channel=1
Note: | Refer to the kernel's hostapd documentation for more wireless configuration options. |
To start the access point launch hostapd:
hostapd /etc/hostapd/hostapd.conf &
This will start up an access point that can be detected by WIFI clients. A DHCP server will likely be desired to assign IP addresses. Refer to Debian's documentation for more details on DHCP configuration.
Debian 9 - Application Development
= Debian 9 - Stretch Cross Compiling
Debian Stretch provides cross compilers from the Debian apt repository archive for Debian Stretch. An install on a workstation can build for the same release on other architectures. A Linux desktop or laptop PC, virtual machine, or chroot will need to be used for this. Debian Stretch for a workstation can be downloaded from here.
From a Debian workstation (not the target), run these commands to set up the cross compiler:
# Run "lsb_release -a" and verify Debian 9.X is returned. These instructions are not
# expected to work on any other version or distribution.
su root
# Not needed for the immediate apt-get install, but used
# so we can install package:armhf for cross compiling
dpkg --add-architecture armhf
apt-get update
apt-get install curl build-essential crossbuild-essential-armhf -y
This will install a toolchain that can be used with the prefix "arm-linux-gnueabihf-". The standard GCC tools will start with that name, eg "arm-linux-gnueabihf-gcc".
The toolchain can now compile a simple hello world application. Create hello-world.c on the Debian workstation:
#include <stdio.h>
int main(){
printf("Hello World\n");
}
To compile this:
arm-linux-gnueabihf-gcc hello-world.c -o hello-world
file hello-world
This will return that the binary created is for ARM. Copy this to the target platform to run it there.
Debian Stretch supports multiarch which can install packages designed for other architectures. On workstations this is how 32-bit and 64-bit support is provided. This can also be used to install armhf packages on an x86 based workstation.
This cross compile environment can link to a shared library from the Debian root. The package would be installed in Debian on the workstation to provide headers and libraries. This is included in most "-dev" packages. When run on the arm target it will also need a copy of the library installed, but it does not need the -dev package.
apt-get install libcurl4-openssl-dev:armhf
# Download the simple.c example from curl:
wget https://raw.githubusercontent.com/bagder/curl/master/docs/examples/simple.c
# After installing the supporting library, curl will link as compiling on the unit.
arm-linux-gnueabihf-gcc simple.c -o simple -lcurl
Copy the binary to the target platform and run on the target. This can be accomplished with network protocols like NFS, SCP, FTP, etc.
If any created binaries do not rely on hardware support like GPIO or CAN, they can be run using 'qemu'.
# using the hello world example from before:
./hello-world
# Returns Exec format error
apt-get install qemu-user-static
./hello-world
Debian 9 - Installing New Software
Debian provides the apt-get system which allows management of pre-built applications. The apt tools require a network connection to the internet in order to automatically download and install new software. The update command will download a list of the current versions of pre-built packages.
apt-get update
A common example is installing Java runtime support for a system. Find the package name first with search, and then install it.
root@ts:~# apt-cache search openjdk default-jdk - Standard Java or Java compatible Development Kit default-jdk-doc - Standard Java or Java compatible Development Kit (documentation) default-jdk-headless - Standard Java or Java compatible Development Kit (headless) default-jre - Standard Java or Java compatible Runtime default-jre-headless - Standard Java or Java compatible Runtime (headless) jtreg - Regression Test Harness for the OpenJDK platform libreoffice - office productivity suite (metapackage) openjdk-8-dbg - Java runtime based on OpenJDK (debugging symbols) openjdk-8-demo - Java runtime based on OpenJDK (demos and examples) openjdk-8-doc - OpenJDK Development Kit (JDK) documentation openjdk-8-jdk - OpenJDK Development Kit (JDK) openjdk-8-jdk-headless - OpenJDK Development Kit (JDK) (headless) openjdk-8-jre - OpenJDK Java runtime, using Hotspot JIT openjdk-8-jre-headless - OpenJDK Java runtime, using Hotspot JIT (headless) openjdk-8-jre-zero - Alternative JVM for OpenJDK, using Zero/Shark openjdk-8-source - OpenJDK Development Kit (JDK) source files uwsgi-app-integration-plugins - plugins for integration of uWSGI and application uwsgi-plugin-jvm-openjdk-8 - Java plugin for uWSGI (OpenJDK 8) uwsgi-plugin-jwsgi-openjdk-8 - JWSGI plugin for uWSGI (OpenJDK 8) uwsgi-plugin-ring-openjdk-8 - Closure/Ring plugin for uWSGI (OpenJDK 8) uwsgi-plugin-servlet-openjdk-8 - JWSGI plugin for uWSGI (OpenJDK 8) java-package - Utility for creating Java Debian packages
In this case, the wanted package will likely be the "openjdk-8-jre" package. Names of packages can be found on Debian's wiki pages or the packages site.
With the package name apt-get install can be used to install the prebuilt packages.
apt-get install openjdk-8-jre
# More than one package can be installed at a time.
apt-get install openjdk-8-jre nano vim mplayer
For more information on using apt-get refer to Debian's documentation here.
Debian 9 - Setting up SSH
To install the SSH server, install the package with apt-get:
apt-get install openssh-server
Debian Stretch by default disallows logins directly from the user "root". Additionally, SSH will not allow remote connections without a password or valid SSH key pair. This means in order to SSH to the device, a user account must first be created, and a password set:
useradd --create-home --shell /bin/bash newuser
passwd newuser
After this setup it is now possible to connect to the device as user "newuser" from a remote PC supporting SSH. On Linux/OS X this is the "ssh" command, or from Windows using a client such as PuTTY.
Debian 9 - Starting Automatically
A systemd service can be created to start up headless applications. Create a file in /etc/systemd/system/yourapp.service
[Unit]
Description=Run an application on startup
[Service]
Type=simple
ExecStart=/usr/local/bin/your_app_or_script
[Install]
WantedBy=multi-user.target
If networking is a dependency add "After=network.target" in the Unit section. Once you have this file in place add it to startup with:
# Start the app on startup, but will not start it now
systemctl enable yourapp.service
# Start the app now, but doesn't change auto startup
systemctl start yourapp.service
Note: | See the systemd documentation for in depth documentation on services. |
To start an application on bootup with X11 instead change the x-session-manager. By default the system starts xfce:
root@ts:~# ls -lah /usr/bin/x-session-manager
lrwxrwxrwx 1 root root 35 May 26 2015 /usr/bin/x-session-manager -> /etc/alternatives/x-session-manager
root@ts:~# ls -lah /etc/alternatives/x-session-manager
lrwxrwxrwx 1 root root 19 May 26 2015 /etc/alternatives/x-session-manager -> /usr/bin/startxfce4
The x-session can be modified to only start specified processes. Create the file /usr/bin/mini-x-session with these contents:
#!/bin/bash
matchbox-window-manager -use_titlebar no &
exec xfce4-terminal
You may need to "apt-get install matchbox-window-manager." first. This is a tiny window manager which also has a few flags that simplify embedded use. Now enable this session manager and restart slim to restart x11 and show it now.
chmod a+x /usr/bin/mini-x-session
rm /etc/alternatives/x-session-manager
ln -s /usr/bin/mini-x-session /etc/alternatives/x-session-manager
service slim restart
If the x-session-manager process ever closes x11 will restart. The exec command allows a new process to take over the existing PID. In the above example xfce4-terminal takes over the PID of x-session-manager. If the terminal is closed with commands like exit the slim/x11 processes will restart.
Debian 8 - Jessie
Debian 8 - Getting Started
Once installed, the default user is "root" with no password.
Note: | This is a shared image that supports the TS-4900, TS-7970, and TS-TPC-7990. |
To prepare an SD card, use partitioning tools such as 'fdisk' 'cfdisk' or 'gparted' in linux to create a single linux partition on the SD card. Once the partition is set up and formatted, extract the above tarball with:
# Assuming your SD card is /dev/sdc with one partition
mkfs.ext3 /dev/sdc1
mkdir /mnt/sd/
sudo mount /dev/sdc1 /mnt/sd/
sudo tar --numeric-owner -xjf debian-armhf-jessie-latest.tar.bz2 -C /mnt/sd
sudo umount /mnt/sd
sync
Note: | The ext4 filesystem can be used instead of ext3, but it may require additional options. U-Boot does not support the 64bit addressing added as the default behavior in recent revisions of mkfs.ext4. If using e2fsprogs 1.43 or newer, the options "-O ^64bit,^metadata_csum" must be used with ext4 for proper compatibility. Older versions of e2fsprogs do not need these options passed nor are they needed for ext3. |
To rewrite the eMMC the unit must be booted to SD or any other media that is not eMMC. Once booted, run the following commands.:
mkfs.ext3 /dev/mmcblk2p1
mkdir /mnt/emmc
mount /dev/mmcblk2p1 /mnt/emmc
wget -qO- https://files.embeddedTS.com/ts-socket-macrocontrollers/ts-4900-linux/distributions/debian/debian-armhf-jessie-latest.tar.bz2 | tar xj -C /mnt/emmc/
umount /mnt/emmc
sync
The same commands can be used to write a SATA drive by substituting /dev/mmcblk2p1 with /dev/sda1.
Debian 8 - Networking
From almost any Linux system you can use 'ip' command or the 'ifconfig' and 'route' commands to initially set up the network.
# Bring up the CPU network interface
ifconfig eth0 up
# Or if you're on a baseboard with a second ethernet port, you can use that as:
ifconfig eth1 up
# Set an ip address (assumes 255.255.255.0 subnet mask)
ifconfig eth0 192.168.0.50
# Set a specific subnet
ifconfig eth0 192.168.0.50 netmask 255.255.0.0
# Configure your route. This is the server that provides your internet connection.
route add default gw 192.168.0.1
# Edit /etc/resolv.conf for your DNS server
echo "nameserver 192.168.0.1" > /etc/resolv.conf
Most networks will offer a DHCP server, an IP address can be obtained from a server with a single command in linux:
Configure DHCP in Debian:
# To setup the default CPU ethernet port
dhclient eth0
# Or if you're on a baseboard with a second ethernet port, you can use that as:
dhclient eth1
# You can configure all ethernet ports for a dhcp response with
dhclient
Systemd provides a networking configuration option to allow for automatic configuration on startup. Systemd-networkd has a number of different configuration files, some of the default examples and setup steps are outlined below.
/etc/systemd/network/eth.network
[Match]
Name=eth*
[Network]
DHCP=yes
To use DHCP to configure DNS via systemd, start and enable the network name resolver service, systemd-resolved:
systemctl start systemd-resolved.service
systemctl enable systemd-resolved.service
ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
For a static config create a network configuration for that specific interface.
/etc/systemd/network/eth0.network
[Match]
Name=eth0
[Network]
Address=192.168.0.50/24
Gateway=192.168.0.1
DNS=192.168.0.1
For more information on networking, see Debian and systemd's documentation:
Debian 8 - WIFI Client
If connecting to a WPA/WPA2 network, a wpa_supplicant config file must first be created:
wpa_passphrase yournetwork yournetworkpassphrase > /etc/wpa_supplicant/wpa_supplicant-wlan0.conf
Create the file /lib/systemd/system/wpa_supplicant@.service with these contents
[Unit]
Description=WPA supplicant daemon (interface-specific version)
Requires=sys-subsystem-net-devices-%i.device
After=sys-subsystem-net-devices-%i.device
[Service]
Type=simple
ExecStart=/sbin/wpa_supplicant -c/etc/wpa_supplicant/wpa_supplicant-%I.conf -i%I
[Install]
Alias=multi-user.target.wants/wpa_supplicant@%i.service
Create the file /etc/systemd/network/wlan0.network with:
[Match]
Name=wlan0
[Network]
DHCP=yes
See the systemctl-networkd example for setting a static IP for a network interface. The wlan0.network can be configured the same way as an eth.network.
To enable all of the changes that have been made, run the following commands:
systemctl enable wpa_supplicant@wlan0
systemctl start wpa_supplicant@wlan0
systemctl restart systemd-networkd
Debian 8 - WIFI Access Point
First, hostapd needs to be installed in order to manage the access point on the device:
apt-get update && apt-get install hostapd -y
Note: | The install process will start an unconfigured hostapd process. This process must be killed and restarted before a new hostapd.conf will take effect. |
Edit /etc/hostapd/hostapd.conf to include the following lines:
interface=wlan0 driver=nl80211 ssid=YourAPName channel=1
Note: | Refer to the kernel's hostapd documentation for more wireless configuration options. |
To start the access point launch hostapd:
hostapd /etc/hostapd/hostapd.conf &
This will start up an access point that can be detected by WIFI clients. A DHCP server will likely be desired to assign IP addresses. Refer to Debian's documentation for more details on DHCP configuration.
Debian 8 - Application Development
Debian 8 - Jessie Cross Compiling
Debian Jessie previously provided cross compilers via the Emdebian project. However, Emdebian has been unmaintained for a number of years and is no longer able to provide a viable install package. In order to cross compile from a Debian Jessie workstation, a third party cross compiler is required.
A Debian Jessie install on a workstation has the ability to build for the same release on other architectures using Debian binary libraries. A PC, virtual machine, or chroot will need to be used for this. Install Debian Jessie for your workstation here.
From a Debian workstation (not the target), run the following commands to set up the cross compiler. Note that this expects a 64-bit Debian Jessie install on the workstation. 32-bit installations are not supported at this time.
# Run "lsb_release -a" and verify Debian 8.X is returned. These instructions are not
# expected to work on any other version or distribution.
cd ~
wget http://ftp.embeddedTS.com/ftp/ts-arm-sbc/ts-7553-V2-linux/cross-toolchains/gcc-linaro-4.9-2016.02-x86_64_arm-linux-gnueabihf.tar.xz
# The above toolchain is from Linaro. Other cross compilers can be used but have not been tested.
mkdir cross_compiler
tar xvf gcc-linaro-4.9-2016.02-x86_64_arm-linux-gnueabihf.tar.xz -C ~/cross_compiler
export PATH=$PATH:~/cross_compiler/gcc-linaro-4.9-2016.02-x86_64_arm-linux-gnueabihf/bin/
# The 'export' command needs to be run every time the user logs in. It is possible to add this command to the user's ".bashrc" file
# in their home directory to ensure it is automatically run every time the user is logged in.
su root
dpkg --add-architecture armhf
apt-get update
apt-get install build-essential
This will install a toolchain that can be used with the prefix "arm-linux-gnueabihf-". The standard GCC tools will start with that name, eg "arm-linux-gnueabihf-gcc".
The toolchain can now compile a simple hello world application. Create hello-world.c on the Debian workstation:
#include <stdio.h>
int main(){
printf("Hello World\n");
}
To compile this:
arm-linux-gnueabihf-gcc hello-world.c -o hello-world
file hello-world
This will return that the binary created is for ARM. Copy this to the target platform to run it there.
Debian Jessie supports multiarch which can install packages designed for other architectures. On workstations this is how 32-bit and 64-bit support is provided. This can also be used to install armhf packages on an x86 based workstation.
This cross compile environment can link to a shared library from the Debian root. The package would be installed in Debian on the workstation to provide headers and ".so" files. This is included in most "-dev" packages. When run on the arm target it will also need a copy of the library installed, but it does not need the -dev package. Note that since the cross compiler used is 3rd party and not directly from Debian, some compile commands that include libraries will need additional arguments to tell the compiler and linker where on the workstation to find the necessary headers and libraries. Usually, the additional arguments will look like the following string, however adjustments may need to be made depending on the application.
-I/usr/include -L/usr/lib/arm-linux-gnueabihf -L/lib/arm-linux-gnueabihf -Wl,-rpath=/usr/lib/arm-linux-gnueabihf,-rpath=/lib/arm-linux-gnueabihf
apt-get install libcurl4-openssl-dev:armhf
# Download the simple.c example from curl:
wget https://raw.githubusercontent.com/bagder/curl/master/docs/examples/simple.c
# After installing the supporting library, curl will link as compiling on the unit.
arm-linux-gnueabihf-gcc -I/usr/include -L/usr/lib/arm-linux-gnueabihf -L/lib/arm-linux-gnueabihf -Wl,-rpath=/usr/lib/arm-linux-gnueabihf,-rpath=/lib/arm-linux-gnueabihf simple.c -o simple -lcurl
Copy the binary to the target platform and run on the target. This can be accomplished with network protocols like NFS, SCP, FTP, etc.
If any created binaries do not rely on hardware support like GPIO or CAN, they can be run using qemu.
# using the hello world example from before:
./hello-world
# Returns Exec format error
apt-get install qemu-user-static
./hello-world
Debian 8 - Installing New Software
Debian provides the apt-get system which allows management of pre-built applications. The apt tools require a network connection to the internet in order to automatically download and install new software. The update command will download a list of the current versions of pre-built packages.
Older Debian releases are moved to a different server to indicate it is no longer getting security updates. To download packages for these older distributions, edit /etc/apt/sources.list
to only have the following lines:
Jessie:
deb http://archive.debian.org/debian/ jessie main deb-src http://archive.debian.org/debian/ jessie main
Wheezy:
deb http://archive.debian.org/debian/ wheezy main deb-src http://archive.debian.org/debian/ wheezy main
After modifying that file, be sure to update the package list:
apt-get update
A common example is installing Java runtime support for a system. Find the package name first with search, and then install it.
root@ts:~# apt-cache search openjdk jvm-7-avian-jre - lightweight virtual machine using the OpenJDK class library freemind - Java Program for creating and viewing Mindmaps icedtea-7-plugin - web browser plugin based on OpenJDK and IcedTea to execute Java applets default-jdk - Standard Java or Java compatible Development Kit default-jdk-doc - Standard Java or Java compatible Development Kit (documentation) default-jre - Standard Java or Java compatible Runtime default-jre-headless - Standard Java or Java compatible Runtime (headless) jtreg - Regression Test Harness for the OpenJDK platform libreoffice - office productivity suite (metapackage) icedtea-7-jre-jamvm - Alternative JVM for OpenJDK, using JamVM openjdk-7-dbg - Java runtime based on OpenJDK (debugging symbols) openjdk-7-demo - Java runtime based on OpenJDK (demos and examples) openjdk-7-doc - OpenJDK Development Kit (JDK) documentation openjdk-7-jdk - OpenJDK Development Kit (JDK) openjdk-7-jre - OpenJDK Java runtime, using Hotspot Zero openjdk-7-jre-headless - OpenJDK Java runtime, using Hotspot Zero (headless) openjdk-7-jre-lib - OpenJDK Java runtime (architecture independent libraries) openjdk-7-source - OpenJDK Development Kit (JDK) source files uwsgi-app-integration-plugins - plugins for integration of uWSGI and application uwsgi-plugin-jvm-openjdk-7 - Java plugin for uWSGI (OpenJDK 7) uwsgi-plugin-jwsgi-openjdk-7 - JWSGI plugin for uWSGI (OpenJDK 7)
In this case you will want the openjdk-7-jre package. Names of packages are on Debian's wiki or the packages site.
With the package name apt-get install can be used to install the prebuilt packages.
apt-get install openjdk-7-jre
# More than one package can be installed at a time.
apt-get install openjdk-7-jre nano vim mplayer
For more information on using apt-get refer to Debian's documentation here.
Debian 8 - Setting up SSH
To install ssh, install the package as normal with apt-get:
apt-get install openssh-server
Make sure the device is configured on the network and set a password for the remote user. SSH will not allow remote connections without a password or a valid SSH key pair.
passwd root
Note: | The default OpenSSH server will not permit root to login via SSH as a security precaution. To allow root to log in via ssh anyway, edit the /etc/ssh/sshd_config file and add the line PermitRootLogin yes in the authentication section. This change will take effect after reboot or after sshd service restart.
|
After this setup it is now possible to connect from a remote PC supporting SSH. On Linux/OS X this is the "ssh" command, or from Windows using a client such as PuTTY.
Note: | If a DNS server is not present on the target network, it is possible to save time at login by adding "UseDNS no" in /etc/ssh/sshd_config. |
Debian 8 - Starting Automatically
A systemd service can be created to start up headless applications. Create a file in /etc/systemd/system/yourapp.service
[Unit]
Description=Run an application on startup
[Service]
Type=simple
ExecStart=/usr/local/bin/your_app_or_script
[Install]
WantedBy=multi-user.target
If networking is a dependency add "After=network.target" in the Unit section. Once you have this file in place add it to startup with:
# Start the app on startup, but will not start it now
systemctl enable yourapp.service
# Start the app now, but doesn't change auto startup
systemctl start yourapp.service
Note: | See the systemd documentation for in depth documentation on services. |
To start an application on bootup with X11 instead change the x-session-manager. By default the system starts xfce:
root@ts:~# ls -lah /usr/bin/x-session-manager
lrwxrwxrwx 1 root root 35 May 26 2015 /usr/bin/x-session-manager -> /etc/alternatives/x-session-manager
root@ts:~# ls -lah /etc/alternatives/x-session-manager
lrwxrwxrwx 1 root root 19 May 26 2015 /etc/alternatives/x-session-manager -> /usr/bin/startxfce4
The x-session can be modified to only start specified processes. Create the file /usr/bin/mini-x-session with these contents:
#!/bin/bash
matchbox-window-manager -use_titlebar no &
exec xfce4-terminal
You may need to "apt-get install matchbox-window-manager." first. This is a tiny window manager which also has a few flags that simplify embedded use. Now enable this session manager and restart slim to restart x11 and show it now.
chmod a+x /usr/bin/mini-x-session
rm /etc/alternatives/x-session-manager
ln -s /usr/bin/mini-x-session /etc/alternatives/x-session-manager
service slim restart
If the x-session-manager process ever closes x11 will restart. The exec command allows a new process to take over the existing PID. In the above example xfce4-terminal takes over the PID of x-session-manager. If the terminal is closed with commands like exit the slim/x11 processes will restart.