TS-4900 Debian 12 Sections

From embeddedTS Manuals

Debian 12 - Bookworm

Debian 12 - Getting Started

This Debian release is available in 3 flavors with various packages.

Image Estimated Size Description
debian-armhf-bookworm-x11-latest.tar.bz2 925 MiB
  • Includes 5.10 kernel with tsimx6_defconfig that includes broad driver support
  • Base Debian with common utils
  • Common embedded tools (i2c, can, gpio, iio, serial tools, etc)
  • Includes hardware support
  • Networking tools (ethernet, wifi, bluetooth)
  • Includes Development tools
  • Includes X11 that launches matchbox and xterm on startup
  • Includes touchscreen support
debian-armhf-bookworm-headless-latest.tar.bz2 681 MiB
  • Includes 5.10 kernel with tsimx6_defconfig that includes broad driver support
  • Base Debian with common utils
  • Common embedded tools (i2c, can, gpio, iio, serial tools, etc)
  • Includes hardware support
  • Networking tools (ethernet, wifi, bluetooth)
  • Includes Development tools
debian-armhf-bookworm-minimal-latest.tar.bz2 223 MiB
  • Includes 5.10 kernel with tsimx6_minimal_defconfig that includes bare minimum driver support and kernel options required by Debian.
  • Includes base Debian rootfs adding only what is required for Ethernet support.

The default login is root with no password.

To write this to an SD card, first partition the SD card to have one large ext3, or ext4 partition. See the guide here for more information. Once it is formatted, extract this tar 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-bookworm-x11-latest.tar.bz2 -C /mnt/sd
sudo umount /mnt/sd
sync

To rewrite the eMMC, boot to the SD card. You cannot rewrite the emmc while it is mounted elsewhere, or used to currently boot the system. Once booted to the SD, run:

mkfs.ext3 /dev/mmcblk2p1
mkdir /mnt/emmc
mount /dev/mmcblk2p1 /mnt/emmc
wget -qO- https://files.embeddedts.com/ts-arm-sbc/ts-7970-linux/distributions/debian/debian-armhf-bookworm-x11-latest.tar.bz2 | tar --numeric-owner -xj -C /mnt/emmc/
umount /mnt/emmc
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.

Debian 12 - Networking

The network in Debian is configured with /etc/network/interfaces. For complete documentation, see Debian's documentation here

Some common examples are shown below. On this release network interfaces follow the predictible network interface names. Run ip addr show to get a list of the network interfaces.

Most commonly:

  • end0 - Ethernet device 0 (CPU Ethernet)
  • enp1s0 - Ethernet PCIe port 1 slot 0 ethernet
  • usb<mac> - USB ethernet
  • wlan0 - WIFI

DHCP on end0. Edit the file /etc/network/interfaces and add:

auto end0
allow-hotplug end0
iface end0 inet dhcp

Static IP on end0. Edit the file /etc/network/interfaces and add:

auto end0
iface end0 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 12 - 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 12 - 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 12 - 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 12 - 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
passwd root # Set any password

If you ssh to this system it will now support ssh as root.

Debian 12 - 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 12 - Cross Compiling

Debian provides cross toolchains within their distribution for different architectures.

For best portability we recommend using a container like docker to run a Debian 12 rootfs for the toolchain. This will allow a consistent toolchain to run from almost any Linux system that can run Docker. Keep in mind that while docker does run under OSX and Windows, these are run under a case insensitive filesystem which will cause problems with complex builds like the Linux kernel so a Linux host is still recommended.

  • Ubuntu/Debian:
sudo apt-get install docker.io -y
  • Fedora
sudo dnf install docker -y

After installing docker on any distribution make sure your user is in the docker group:

# Add your user to the docker group.  You may need to logout/log back in.
sudo usermod -aG docker $USER

Make sure you can run docker's hello world image as your user to verify it is working:

docker run hello-world

Now create a file Dockerfile:

sudo mkdir -p /opt/docker-toolchain/docker-debian-bookworm-armhf
# Use any preferred editor, vim/emacs/nano/etc
sudo nano /opt/docker-toolchain/docker-debian-bookworm-armhf/Dockerfile
# syntax = docker/dockerfile:1.2

FROM debian:bookworm

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 \
    libyaml-dev \
    locales \
    lz4 \
    lzop \
    make \
    multistrap \
    ncurses-dev \
    pkg-config \
    python3 \
    python3-cbor \
    python3-pexpect \
    python3-pip \
    qemu-user-static \
    rsync \
    runit \
    socat \
    srecord \
    swig \ 
    texinfo \
    u-boot-tools \
    zstd \
    unzip \
    vim \
    wget \
    xz-utils

# Provide a more friendly name
ENV debian_chroot debian_bookworm
RUN echo "PS1='\${debian_chroot}\\[\033[01;32m\\]@\\H\[\\033[00m\\]:\\[\\033[01;34m\\]\\w\\[\\033[00m\\]\\$ '" >> /etc/bash.bashrc

# Set up locales
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

Next make a shell script to enter into this docker container. Create /usr/local/bin/docker-debian-bookworm:

# Use any preferred editor, vim/emacs/nano/etc
sudo nano /usr/local/bin/docker-debian-bookworm
#!/bin/bash -e

# Enters a docker running Debian 12 Bookworm
# Any arguments are run in the docker, or if no arguments it runs a shell

export TAG=debian-bookworm-armdev
SCRIPTPATH=$(readlink -f "$0")
DOCKERPATH=/opt/docker-toolchain/docker-debian-bookworm-armhf/

DOCKER_BUILDKIT=1 docker build --tag "$TAG" "$DOCKERPATH" --quiet

exec docker run --rm \
	-it \
	--volume "$(pwd)":/work \
	--user $(id -g):$(id -u) \
	-w /work \
	-e HOME=/tmp \
	"$TAG" \
	$@;

Make this executable, and call it:

sudo chmod a+x /usr/local/bin/docker-debian-bookworm

# dont run as root
docker-debian-bookworm

The first time this runs it will download a base Debian image, and run the above apt-get commands which may take around 10 or so minutes depending on your internet connection and disk speed. After it has run once, it will stay cached and adds almost no overhead to run.

This docker can be thought of as a very low overhead virtual machine that only has access to the directory where it is run.

For example, to build a simple c project, create a ~/Desktop/hello-world/hello.c:

mkdir -p ~/Desktop/hello-world/

In ~/Desktop/hello-world/hello.c:

#include <stdio.h>

int main() {
    printf("Hello world!\n");
    return 0;
}

We can now use the docker in that directory to use Debian's cross compiler to create a binary that targets armhf:

user@hostname:~$ cd ~/Desktop/hello-world/
user@hostname:~/Desktop/hello-world$ docker-debian-bookworm
sha256:a92e70c3d7346654b34c0442da20ae634901fd25d1a89dd26517e7d1c1d00c47
debian_bookworm@a8ddfa54989f:/work$ ls
hello.c
debian_bookworm@a8ddfa54989f:/work$ arm-linux-gnueabihf-gcc hello.c -o hello
debian_bookworm@a8ddfa54989f:/work$ arm-linux-gnueabihf-strip hello
debian_bookworm@a8ddfa54989f:/work$ file hello
hello: ELF 32-bit LSB pie executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, BuildID[sha1]=ffda981721a1531418ed1da27238707851ae0126, for GNU/Linux 3.2.0, stripped

Debian 12 - Kernel Recompile

To compile the kernel you should use the Debian cross compile docker from a linux workstation.

We can use a shell script to enter the docker, and compile the kernel into a tar that can be distributed to the board. For example:

mkdir ~/Projects/kernel-5.10/
cd ~/Projects/kernel-5.10/
git clone https://github.com/embeddedTS/linux-lts.git -b linux-5.10.y linux

Make a ~/Projects/kernel-5.10/build.sh with:

#!/bin/bash -e

if [ ! -e "/.dockerenv" ]; then
	exec docker-debian-bookworm "$0 $@";
fi

export ARCH=arm
export CROSS_COMPILE="arm-linux-gnueabihf-"
export LOADADDR=0x10008000

cd linux

if [ "$#" != "0" ]; then
        "$@"
        exit 0;
fi

## Make any changes in "make menuconfig" or driver modifications, then compile
make -j"$(nproc --all)" all uImage

# Install to a temporary directory
TEMPDIR=$(mktemp -d)
export TEMPDIR
mkdir "$TEMPDIR"/boot/
cp arch/arm/boot/uImage  "$TEMPDIR"/boot/uImage
cp arch/arm/boot/zImage  "$TEMPDIR"/boot/zImage
cp arch/arm/boot/dts/imx6*-ts*.dtb "$TEMPDIR"/boot/
INSTALL_MOD_PATH="${TEMPDIR}/usr/" make modules_install
cd ../

fakeroot sh -c "chmod 755 $TEMPDIR;
	chown -R root:root $TEMPDIR;
	tar cjf kernel.tar.bz2 -C $TEMPDIR .;
	rm -rf $TEMPDIR";

Make this executable:

chmod a+x ~/Projects/kernel-5.10/build.sh

The kernel can be compiled by running these two commands:

./build.sh make ts_defconfig
./build.sh # No arguments runs the build and packages the kernel

# This will output the build in the current directory as kernel.tar.bz2

Any arguments to this script will be executed in the linux path. For example:

./build.sh make ts_defconfig
# Customize the kernel config
./build.sh make menuconfig
# Test a compile (does not package the install)
./build.sh make
# Get a shell prompt in the kernel sources to run commands manually:
./build.sh bash

The kernel.tar.bz2 from this build script can be extracted from a board, or over an image to install this kernel. For example, copy this to the SBC and run:

tar -xhf kernel.tar.bz2 -C /

From a workstation this can similarly be used to install over a mounted SD image:

sudo mount /dev/sdc1 /mnt/sd/
sudo tar -xhf kernel.tar.bz2 -C /mnt/sd/
sudo umount /mnt/sd/