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Debian Bullseye 11 with 5.4-2.1.x-imx_var01 Linux release

DART-6UL in this wiki refers to both the Variscite DART-6UL and VAR-SOM-6UL SOMs.

Overview

This page describes how to build and install Debian distribution (Bullseye) on Variscite boards with DART-6UL.

Please note that the build script is based on debootstrap. As described in the following instructions, it's kindly suggested to create the build folder on the main Ubuntu volume on your host PC rather than an external media.
Using an external media, although automatically mounted, will cause debootstrap to complain about access rights (even when running the script with sudo).

For additional details about this release, refer to the Release Notes.

Create build environment

These instructions were tested on Ubuntu 18.04/20.04 x64 host PCs. When using other distributions, there may be issues.

Note: Variscite provides Docker containers that can be used for a development environment as an alternative to using a virtual machine or a dedicated computer.

To learn more, please see Variscite's Docker Build Environment guide.

Windows with WSL/WSL2 is not supported for development

Installing required packages

On Ubuntu building machine:

$ sudo apt-get install binfmt-support qemu qemu-user-static debootstrap kpartx \
lvm2 dosfstools gpart binutils bison git lib32ncurses5-dev libssl-dev gawk wget \
git-core diffstat unzip texinfo gcc-multilib build-essential chrpath socat libsdl1.2-dev \
autoconf libtool libglib2.0-dev libarchive-dev xterm sed cvs subversion \
kmod coreutils texi2html bc docbook-utils help2man make gcc g++ \
desktop-file-utils libgl1-mesa-dev libglu1-mesa-dev mercurial automake groff curl \
lzop asciidoc u-boot-tools mtd-utils device-tree-compiler flex cmake zstd udisks2  libgnutls28-dev \
python-pysqlite2 python-git python-m2crypto python-pyelftools

While installing the packages, Ubuntu 20.04 users may receive the warning

Package python-git is not available, ...

Since the package is only available in up to Ubuntu 18.04, just ignore it and run:

$ sudo apt-get install python3-git python3-m2crypto python3-pyelftools

Note: If you are using Ubuntu 20.04 the QEMU package must be updated to latest version (>= 1:4.2-3ubuntu6.19).
To check the currently installed version of the qemu-user-static package on Ubuntu 20.04 LTS, use the below command:

$ apt list qemu-user-static

Deploy source

Important update:

As of March 31, 2023, all codeaurora.org repositories have been migrated to other platforms, and the project has been shut down.
For more information, please visit: https://bye.codeaurora.org/

In this context, errors may occur when deploying the Debian sources, such as:
fatal: unable to look up source.codeaurora.org (port 9418) (No address associated with hostname)

Variscite has updated all relevant software repositories. Please refer to the patch(es):

Download archive containing the build script and support files for building Debian Bullseye for this board:

$ cd ~
$ git clone https://github.com/varigit/debian-var.git -b debian_bullseye_var01 debian_imx6ul-var-dart

Create environment (Internet connection should be available):

$ cd ~/debian_imx6ul-var-dart
$ MACHINE=imx6ul-var-dart ./var_make_debian.sh -c deploy

This environment prepared to build.

Make Debian

Build all

Internet connection should be available

$ cd ~/debian_imx6ul-var-dart
$ sudo MACHINE=imx6ul-var-dart ./var_make_debian.sh -c all |& tee build.log

Build by parts

Build bootloader

$ cd ~/debian_imx6ul-var-dart
$ sudo MACHINE=imx6ul-var-dart ./var_make_debian.sh -c bootloader

Build kernel, dtb files, kernel modules, and kernel headers

$ cd ~/debian_imx6ul-var-dart
$ sudo MACHINE=imx6ul-var-dart ./var_make_debian.sh -c kernel
$ sudo MACHINE=imx6ul-var-dart ./var_make_debian.sh -c modules
$ sudo MACHINE=imx6ul-var-dart ./var_make_debian.sh -c kernelheaders

Build rootfs

Internet connection should be available

$ cd ~/debian_imx6ul-var-dart
$ sudo MACHINE=imx6ul-var-dart ./var_make_debian.sh -c rootfs

Pack rootfs

To create the root file system archive (rootfs.tar.gz) and UBI image (rootfs.ubi.img), run the following commands:

$ cd ~/debian_imx6ul-var-dart
$ sudo MACHINE=imx6ul-var-dart ./var_make_debian.sh -c rtar
$ sudo MACHINE=imx6ul-var-dart ./var_make_debian.sh -c rubi

Note: The NAND filesystem is console only and may not have all the features as eMMC/SD card
To fit the NAND UBIFS filesystem as per your need, optimize the UBIFS by removing the packages.

Create boot SD card

  1. Follow the above steps for make rootfs, kernel, bootloader;
  2. Insert the SD card to card reader connected to a host system;
  3. Run the following commands (Caution! All data on the card will be destroyed):
$ cd ~/debian_imx6ul-var-dart
$ sudo MACHINE=imx6ul-var-dart ./var_make_debian.sh -c sdcard -d /dev/sdX

where '/dev/sdX' path to the block SD device in your system.

Create a boot SD card image using a loop device

It is also possible to use the "MACHINE=imx6ul-var-dart ./var_make_debian.sh" script to create a boot SD card image, while using a loop device instead of attaching a real SD card.

Create an empty file using the following command:

$ dd if=/dev/zero of=imx6ul-var-dart-debian-sd.img bs=1M count=3720

The above command creates a 3700MiB file representing the SD card.

Attach the first available loop device to this file:

$ sudo losetup -Pf imx6ul-var-dart-debian-sd.img

To find the actual loop device being used, run:

$ losetup -a | grep imx6ul-var-dart-debian-sd.img

Write the content to the loop device to generate the SD card image:

$ sudo MACHINE=imx6ul-var-dart ./var_make_debian.sh -c sdcard -d /dev/loopX

(Replace /dev/loopX with your actual loop device, e.g. /dev/loop0)

Detach the loop device from the file:

$ sudo losetup -d /dev/loopX

To compress the SD card image file use the following command:

$ gzip -9 imx6ul-var-dart-debian-sd.img

To write the SD card image to a real SD card device use the following command:

$ zcat imx6ul-var-dart-debian-sd.img.gz | sudo dd of=/dev/sdX bs=1M && sync

(Replace /dev/sdX with your actual SD device, e.g. /dev/sdb)

Boot the board with a bootable SD card

Note: The WiFi is not operational when booting from SD card, as the WiFi and SD card are using the same SDIO interface.
A typical use-case is to boot from an SD card, flash the eMMC/NAND flash, and re-boot from the eMMC/NAND flash to have the WiFi operational.

Setting the Boot Mode

Booting your system from an SD card requires switching the Boot DIP switches. See picture below.
On the VAR-6ULCustomBoard (with a DART-6UL):

Boot switch 6ul1.jpg

  • "00" The current position in the picture will set the system to boot from SD card
  • "01" Moving the right switch will set the system to boot from eMMC
  • "10" Moving the left switch will set the system to boot from NAND flash
  • "11" is illegal.

Be aware that your system has eMMC or NAND but never both.

On the Concerto-Board (with a VAR-SOM-6UL):

Boot switch concerto.jpg

  • ON-EXT: Boot from the external storage (SD card) - the current position in the picture
  • OFF-INT: Boot from the SOM's internal storage (eMMC/NAND flash)

Automatic device tree selection in U-Boot

Enable/Disable Automatic Device Tree selection

To enable the automatic device tree selection in U-Boot (already enabled by default):

$ setenv fdt_file undefined
$ saveenv

To disable the automatic device tree selection in U-Boot, set the device tree file manually:

$ setenv fdt_file YOUR_DTB_FILE
$ saveenv

Comment:
Make sure you don't set an inappropriate dtb file, like a dtb with nand on a SOM that has eMMC, or a dtb for mx6ull on a SOM with an mx6ul SOC.

Build Results

The resulted images are located in ~/debian_imx6ul-var-dart/output/.

Image name
How to use
rootfs.tar.gz Root filesystem tarball used for installation on SD card and eMMC
rootfs.ubi.img Console only image for installation on NAND flash
zImage Linux kernel image
SPL.nand SPL built for NAND. The SPL is pre-U-Boot SW component, required for DDR initialization
SPL.mmc SPL built for SD card and eMMC boot. The SPL is pre-U-Boot SW component, required for DDR initialization
u-boot.img.nand U-Boot built for NAND flash
u-boot.img.mmc U-Boot built for SD card or eMMC
kernel-headers kernel headers folder for package creation
Device Tree name
Details
imx6ull-var-dart-6ulcustomboard-emmc-sd-card.dtb Device tree blob for DART-6UL with i.MX6ULL SOC, eMMC & SD card enabled. (NAND flash & WiFi disabled)
imx6ull-var-dart-6ulcustomboard-emmc-sd-card-wm8731.dtb Device tree blob for DART-6UL with i.MX6ULL SOC, eMMC, WM8731 & SD card enabled. (NAND flash & WiFi disabled)
imx6ull-var-dart-6ulcustomboard-emmc-wifi.dtb Device tree blob for DART-6UL with i.MX6ULL SOC, eMMC & WiFi enabled. (NAND flash & SD card disabled)
imx6ull-var-dart-6ulcustomboard-emmc-wifi-wm8731.dtb Device tree blob for DART-6UL with i.MX6ULL SOC, eMMC, WM8731 & WiFi enabled. (NAND flash & SD card disabled)
imx6ull-var-dart-6ulcustomboard-nand-sd-card.dtb Device tree blob for DART-6UL with i.MX6ULL SOC, NAND flash & SD card enabled. (eMMC & WiFi disabled)
imx6ull-var-dart-6ulcustomboard-nand-sd-card-wm8731.dtb Device tree blob for DART-6UL with i.MX6ULL SOC, NAND flash, WM8731 & SD card enabled. (eMMC & WiFi disabled)
imx6ull-var-dart-6ulcustomboard-nand-wifi.dtb Device tree blob for DART-6UL with i.MX6ULL SOC, NAND flash & WiFi enabled. (eMMC & SD card disabled)
imx6ull-var-dart-6ulcustomboard-nand-wifi-wm8731.dtb Device tree blob for DART-6UL with i.MX6ULL SOC, NAND flash, WM8731 & WiFi enabled. (eMMC & SD card disabled)
imx6ul-var-dart-6ulcustomboard-emmc-sd-card.dtb Device tree blob for DART-6UL with i.MX6UL SOC, eMMC & SD card enabled. (NAND flash & WiFi disabled)
imx6ul-var-dart-6ulcustomboard-emmc-sd-card-wm8731.dtb Device tree blob for DART-6UL with i.MX6UL SOC, eMMC, WM8731 & SD card enabled. (NAND flash & WiFi disabled)
imx6ul-var-dart-6ulcustomboard-emmc-wifi.dtb Device tree blob for DART-6UL with i.MX6UL SOC, eMMC & WiFi enabled. (NAND flash & SD card disabled)
imx6ul-var-dart-6ulcustomboard-emmc-wifi-wm8731.dtb Device tree blob for DART-6UL with i.MX6UL SOC, eMMC, WM8731 & WiFi enabled. (NAND flash & SD card disabled)
imx6ul-var-dart-6ulcustomboard-nand-sd-card.dtb Device tree blob for DART-6UL with i.MX6UL SOC, NAND flash & SD card enabled. (eMMC & WiFi disabled)
imx6ul-var-dart-6ulcustomboard-nand-sd-card-wm8731.dtb Device tree blob for DART-6UL with i.MX6UL SOC, NAND flash, WM8731 & SD card enabled. (eMMC & WiFi disabled)
imx6ul-var-dart-6ulcustomboard-nand-wifi.dtb Device tree blob for DART-6UL with i.MX6UL SOC, NAND flash & WiFi enabled. (eMMC & SD card disabled)
imx6ul-var-dart-6ulcustomboard-nand-wifi-wm8731.dtb Device tree blob for DART-6UL with i.MX6UL SOC, NAND flash, WM8731 & WiFi enabled. (eMMC & SD card disabled)
imx6ulz-var-dart-6ulcustomboard-emmc-sd-card.dtb Device tree blob for DART-6UL with i.MX6ULZ SOC, eMMC & SD card enabled. (NAND flash & WiFi disabled)
imx6ulz-var-dart-6ulcustomboard-emmc-sd-card-wm8731.dtb Device tree blob for DART-6UL with i.MX6ULZ SOC, eMMC, WM8731 & SD card enabled. (NAND flash & WiFi disabled)
imx6ulz-var-dart-6ulcustomboard-emmc-wifi.dtb Device tree blob for DART-6UL with i.MX6ULZ SOC, eMMC & WiFi enabled. (NAND flash & SD card disabled)
imx6ulz-var-dart-6ulcustomboard-emmc-wifi-wm8731.dtb Device tree blob for DART-6UL with i.MX6ULZ SOC, eMMC, WM8731 & WiFi enabled. (NAND flash & SD card disabled)
imx6ulz-var-dart-6ulcustomboard-nand-sd-card.dtb Device tree blob for DART-6UL with i.MX6ULZ SOC, NAND flash & SD card enabled. (eMMC & WiFi disabled)
imx6ulz-var-dart-6ulcustomboard-nand-sd-card-wm8731.dtb Device tree blob for DART-6UL with i.MX6ULZ SOC, NAND flash, WM8731 & SD card enabled. (eMMC & WiFi disabled)
imx6ulz-var-dart-6ulcustomboard-nand-wifi.dtb Device tree blob for DART-6UL with i.MX6ULZ SOC, NAND flash & WiFi enabled. (eMMC & SD card disabled)
imx6ulz-var-dart-6ulcustomboard-nand-wifi-wm8731.dtb Device tree blob for DART-6UL with i.MX6ULZ SOC, NAND flash, WM8731 & WiFi enabled. (eMMC & SD card disabled)
imx6ull-var-som-concerto-board-emmc-sd-card.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULL SOC, eMMC & SD card enabled. (NAND flash & WiFi disabled)
imx6ull-var-som-concerto-board-emmc-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULL SOC, eMMC, WM8731 & SD card enabled. (NAND flash & WiFi disabled)
imx6ull-var-som-concerto-board-emmc-wifi.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULL SOC, eMMC & WiFi enabled. (NAND flash & SD card disabled)
imx6ull-var-som-concerto-board-emmc-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULL SOC, eMMC, WM8731 & WiFi enabled. (NAND flash & SD card disabled)
imx6ull-var-som-concerto-board-nand-sd-card.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULL SOC, NAND flash & SD card enabled. (eMMC & WiFi disabled)
imx6ull-var-som-concerto-board-nand-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULL SOC, NAND flash, WM8731 & SD card enabled. (eMMC & WiFi disabled)
imx6ull-var-som-concerto-board-nand-wifi.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULL SOC, NAND flash & WiFi enabled. (eMMC & SD card disabled)
imx6ull-var-som-concerto-board-nand-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULL SOC, NAND flash, WM8731 & WiFi enabled. (eMMC & SD card disabled)
imx6ul-var-som-concerto-board-emmc-sd-card.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6UL SOC, eMMC & SD card enabled. (NAND flash & WiFi disabled)
imx6ul-var-som-concerto-board-emmc-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6UL SOC, eMMC, WM8731 & SD card enabled. (NAND flash & WiFi disabled)
imx6ul-var-som-concerto-board-emmc-wifi.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6UL SOC, eMMC & WiFi enabled. (NAND flash & SD card disabled)
imx6ul-var-som-concerto-board-emmc-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6UL SOC, eMMC, WM8731 & WiFi enabled. (NAND flash & SD card disabled)
imx6ul-var-som-concerto-board-nand-sd-card.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6UL SOC, NAND flash & SD card enabled. (eMMC & WiFi disabled)
imx6ul-var-som-concerto-board-nand-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6UL SOC, NAND flash, WM8731 & SD card enabled. (eMMC & WiFi disabled)
imx6ul-var-som-concerto-board-nand-wifi.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6UL SOC, NAND flash & WiFi enabled. (eMMC & SD card disabled)
imx6ul-var-som-concerto-board-nand-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6UL SOC, NAND flash, WM8731 & WiFi enabled. (eMMC & SD card disabled)
imx6ulz-var-som-concerto-board-emmc-sd-card.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULZ SOC, eMMC & SD card enabled. (NAND flash & WiFi disabled)
imx6ulz-var-som-concerto-board-emmc-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULZ SOC, eMMC, WM8731 & SD card enabled. (NAND flash & WiFi disabled)
imx6ulz-var-som-concerto-board-emmc-wifi.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULZ SOC, eMMC & WiFi enabled. (NAND flash & SD card disabled)
imx6ulz-var-som-concerto-board-emmc-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULZ SOC, eMMC, WM8731 & WiFi enabled. (NAND flash & SD card disabled)
imx6ulz-var-som-concerto-board-nand-sd-card.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULZ SOC, NAND flash & SD card enabled. (eMMC & WiFi disabled)
imx6ulz-var-som-concerto-board-nand-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULZ SOC, NAND flash, WM8731 & SD card enabled. (eMMC & WiFi disabled)
imx6ulz-var-som-concerto-board-nand-wifi.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULZ SOC, NAND flash & WiFi enabled. (eMMC & SD card disabled)
imx6ulz-var-som-concerto-board-nand-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Concerto board with i.MX6ULZ SOC, NAND flash, WM8731 & WiFi enabled. (eMMC & SD card disabled)
imx6ull-var-som-symphony-board-emmc-sd-card.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULL SOC, eMMC & SD card enabled. (NAND flash & WiFi disabled)
imx6ull-var-som-symphony-board-emmc-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULL SOC, eMMC, WM8731 & SD card enabled. (NAND flash & WiFi disabled)
imx6ull-var-som-symphony-board-emmc-wifi.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULL SOC, eMMC & WiFi enabled. (NAND flash & SD card disabled)
imx6ull-var-som-symphony-board-emmc-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULL SOC, eMMC, WM8731 & WiFi enabled. (NAND flash & SD card disabled)
imx6ull-var-som-symphony-board-nand-sd-card.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULL SOC, NAND flash & SD card enabled. (eMMC & WiFi disabled)
imx6ull-var-som-symphony-board-nand-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULL SOC, NAND flash, WM8731 & SD card enabled. (eMMC & WiFi disabled)
imx6ull-var-som-symphony-board-nand-wifi.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULL SOC, NAND flash & WiFi enabled. (eMMC & SD card disabled)
imx6ull-var-som-symphony-board-nand-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULL SOC, NAND flash, WM8731 & WiFi enabled. (eMMC & SD card disabled)
imx6ul-var-som-symphony-board-emmc-sd-card.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6UL SOC, eMMC & SD card enabled. (NAND flash & WiFi disabled)
imx6ul-var-som-symphony-board-emmc-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6UL SOC, eMMC, WM8731 & SD card enabled. (NAND flash & WiFi disabled)
imx6ul-var-som-symphony-board-emmc-wifi.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6UL SOC, eMMC & WiFi enabled. (NAND flash & SD card disabled)
imx6ul-var-som-symphony-board-emmc-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6UL SOC, eMMC, WM8731 & WiFi enabled. (NAND flash & SD card disabled)
imx6ul-var-som-symphony-board-nand-sd-card.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6UL SOC, NAND flash & SD card enabled. (eMMC & WiFi disabled)
imx6ul-var-som-symphony-board-nand-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6UL SOC, NAND flash, WM8731 & SD card enabled. (eMMC & WiFi disabled)
imx6ul-var-som-symphony-board-nand-wifi.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6UL SOC, NAND flash & WiFi enabled. (eMMC & SD card disabled)
imx6ul-var-som-symphony-board-nand-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6UL SOC, NAND flash, WM8731 & WiFi enabled. (eMMC & SD card disabled)
imx6ulz-var-som-symphony-board-emmc-sd-card.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULZ SOC, eMMC & SD card enabled. (NAND flash & WiFi disabled)
imx6ulz-var-som-symphony-board-emmc-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULZ SOC, eMMC, WM8731 & SD card enabled. (NAND flash & WiFi disabled)
imx6ulz-var-som-symphony-board-emmc-wifi.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULZ SOC, eMMC & WiFi enabled. (NAND flash & SD card disabled)
imx6ulz-var-som-symphony-board-emmc-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULZ SOC, eMMC, WM8731 & WiFi enabled. (NAND flash & SD card disabled)
imx6ulz-var-som-symphony-board-nand-sd-card.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULZ SOC, NAND flash & SD card enabled. (eMMC & WiFi disabled)
imx6ulz-var-som-symphony-board-nand-sd-card-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULZ SOC, NAND flash, WM8731 & SD card enabled. (eMMC & WiFi disabled)
imx6ulz-var-som-symphony-board-nand-wifi.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULZ SOC, NAND flash & WiFi enabled. (eMMC & SD card disabled)
imx6ulz-var-som-symphony-board-nand-wifi-wm8731.dtb Device tree blob for VAR-SOM-6UL on Symphony board with i.MX6ULZ SOC, NAND flash, WM8731 & WiFi enabled. (eMMC & SD card disabled)

Linux console access

User name User password User descriptor
root root system administrator
user user local user
x_user used for X session access

Flash images to NAND / eMMC

In case you are using a SOM with NAND flash, run the following command as root to install Debian on it:

# install_debian.sh -r nand (Follow instructions)

In case you are using a SOM with eMMC, run the following command as root to install Debian on it:

# install_debian.sh -r emmc (Follow instructions)

The above scripts are located in /usr/sbin in the rootfs of the SD card used to boot Debian.

How-to: Test and use an interface

Please see this section in the Yocto developer guide page. It is the same for Debian.

How-to: Modify the kernel configuration

To modify the kernel configuration (add/remove features and drivers) please follow the steps below:

1. $ cd ~/debian_imx6ul-var-dart/src/kernel
2. $ sudo make ARCH=arm mrproper
3. $ sudo make ARCH=arm imx_v7_var_defconfig
4. $ sudo make ARCH=arm menuconfig
5. Navigate the menu and select the desired kernel functionality
6. Exit the menu and answer "Yes" when asked "Do you wish to save your new configuration?"
7. $ sudo make ARCH=arm savedefconfig
8. $ sudo cp arch/arm/configs/imx_v7_var_defconfig arch/arm/configs/imx_v7_var_defconfig.orig
9. $ sudo cp defconfig arch/arm/configs/imx_v7_var_defconfig
10. Follow the instructions above to rebuild kernel and modules, repack rootfs images and recreate SD card

How-to: Build and install a custom device tree

To build and install a custom device tree, add the filename to G_LINUX_DTB in https://github.com/varigit/debian-var/blob/debian_bullseye_var01/variscite/imx6ul-var-dart/imx6ul-var-dart.sh

Build a sample C "Hello, world!" program

Create a file called myhello.c with the following content:

#include <stdio.h>

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

Export the C (cross-)compiler path:

$ export CC=~/debian_imx6ul-var-dart/toolchain/gcc-linaro-6.3.1-2017.05-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc

Compile:

$ $CC myhello.c -o myhello

Now you should have an app called myhello, that can be run on your target board.
You can add it to your rootfs image or copy it directly to the rootfs on the board (using scp, for example).