Debian Bookworm 12.5 based on Yocto Mickledore 4.2 with NXP BSP L6.1.36_2.1.0¶
Note
Since Debian Bookworm with NXP BSP L6.1.36_2.1.0, the build system has transitioned to Yocto. If you previously used an older Debian release, please note that setting up a new development environment may be necessary. Therefore, it is recommended to familiarize yourself with the following guides first:
Installing required packages¶
Please make sure your host PC is running Ubuntu 20.04/22.04 64-bit and is up to date:
Then, install the following packages:
$ sudo apt-get install gawk wget git diffstat unzip texinfo gcc-multilib \
build-essential chrpath socat cpio python3 python3-pip python3-pexpect \
xz-utils debianutils iputils-ping libsdl1.2-dev xterm libyaml-dev libssl-dev
$ sudo apt-get install autoconf libtool libglib2.0-dev libarchive-dev \
sed cvs subversion coreutils texi2html docbook-utils \
help2man make gcc g++ desktop-file-utils libgl1-mesa-dev libglu1-mesa-dev \
mercurial automake groff curl lzop asciidoc u-boot-tools dos2unix mtd-utils pv \
libncurses5 libncurses5-dev libncursesw5-dev libelf-dev zlib1g-dev bc rename \
zstd libgnutls28-dev
$ sudo apt-get install python3-git zstd liblz4-tool
For Ubuntu 20.04 and earlier, install python2:
Starting in Ubuntu 22.04, python2 is no longer available. Install the following to create a symbolic link from python to python3:
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.
Reference documentation¶
Setting Up Yocto Build Environment¶
Configure git user and email:
Fetch and install the Google git-repo tool:
$ mkdir -p ~/bin
# For Ubuntu 20.04 and older, install repo 2.32 according to https://gerrit.googlesource.com/git-repo/+/HEAD/docs/python-support.md:
$ curl https://commondatastorage.googleapis.com/git-repo-downloads/repo-2.32 > ~/bin/repo
# For Ubuntu 22.04 and newer, install the latest repo tool:
$ curl https://commondatastorage.googleapis.com/git-repo-downloads/repo > ~/bin/repo
# Give repo execute permissions and add it to the path:
$ chmod a+x ~/bin/repo
$ export PATH=~/bin:$PATH
Create a build directory:
Now, choose between downloading a release tag, and downloading the latest revision (recommended) and follow only one of the next two bullet sections, accordingly:
- Download the latest revision (recommended)
$ repo init -u https://github.com/varigit/variscite-bsp-platform.git -b mickledore -m imx-6.1.36-2.1.0-debian.xml
$ repo sync -j$(nproc)
or
- Download a release tag
Each release in https://github.com/varigit/variscite-bsp-platform/releases corresponds to a tag.
The tags are also listed in https://github.com/varigit/variscite-bsp-platform/tags
To specify a specific release/tag, run the following:
$ repo init -u https://github.com/varigit/variscite-bsp-platform.git -b refs/tags/TAG_NAME
For example:
$ repo init -u https://github.com/varigit/variscite-bsp-platform.git -b refs/tags/mx8mp-debian-bookworm-6.1.36_2.1.0-v1.1 -m imx-6.1.36-2.1.0-debian.xml
$ repo sync -j$(nproc)
Building the Image¶
Supported images¶
Variscite provides the following images for evaluation purposes:
- var-image-debian: Default Variscite demo image for Debian build with Yocto. This image recipe works currently only with Xwayland
Supported distros¶
The following distros can be used:
- var-debian-xwayland: Distro for Wayland with X11. This distro includes both Wayland and X11 emulation features.
Build Debian Xwayland GUI demo image¶
After the Yocto environment is set up, you need to configure the build environment for your target device:
$ cd ~/debian_imx8mp_var_dart
$ MACHINE=imx8mp-var-dart DISTRO=var-debian-xwayland . var-setup-debian.sh build_debian_xwayland
The above command is only mandatory for the very first build setup. Whenever restarting a newer build session (from a different terminal or in a different time), you can skip the full setup and just run:
Then, the image can be created by running the following bitbake command:
The target rootfs image is located at:
~/debian_imx8mp_var_dart/build_debian_xwayland/tmp/deploy/images/imx8mp-var-dart/var-image-debian-imx8mp-var-dart.wic.gz
Linux console access¶
Default users and passwords¶
| User name | User password | User descriptor |
|---|---|---|
| root | root | system administrator |
| user | user | local user |
You can customize the users during runtime with the common known methods in Debian. Please follow up with the next section if you'd like to customize them during the build.
Customize users during the build¶
The Variscite Debian image is pre-configured to include the user's 'user' and 'root'. While the user 'root' is mandatory, the user 'user' is optional and can be configured or dropped according to your needs (it's also possible to add additional users).
The related statements in the Yocto tree are in 'dynamic-layers/var-debian/recipes-var/images/var-image-common.inc' within the meta layer meta-variscite-sdk-imx.
var-image-common.inc
# Add user with password user and default shell bash
USER_SHELL_BASH ?= "/bin/bash"
# Default password: user
USER_PASSWD_USER ?= "zHipsIr46vtZk"
APTGET_ADD_USERS ?= "user:${USER_PASSWD_USER}:${USER_SHELL_BASH}"
...
This makes use of the API APTGET_ADD_USERS variable of the bitbake class nativeaptinstall.bbclass (can be found in 'classes/nativeaptinstall.bbclass' in the meta layer meta-variscite-debian).
The syntax of the variable APTGET_ADD_USERS is <name:pass:shell>, with the following meaning:
- name: The user name
- pass: An encrypted password (if empty or missing, an empty password will be assigned)
- shell: The default shell (if empty, default is /bin/sh)
For multiple definitions, a space can be used as a separator.
The encrypted password (DES hash) can be created using the tool 'mkpasswd', provided by the package 'whois'.
For instance:
This will generate a hash with a random salt (which match the first 2 characters of the above output). To double-check, we can pass the salt, like:
One can either change the variables in 'var-image-common.inc' directly or overwrite the default values, e.g., in the local.conf ('~/debian_imx8mp_var_dart/build_debian_xwayland/conf/local.conf').
For instance, to configure 2 users, 'user' and 'user2', with the password being the same as the user name:
local.conf
Or to add an additional user to the one already present:
Or drop all additional users (only user 'root'):
Note: If you only want to change the password of the default user 'user', overwrite the variable USER_PASSWD_USER to your needs. The same applies to the user 'root' with the associated variable USER_PASSWD_ROOT.
Create a bootable SD card¶
SD Card Structure¶
This is the structure of our default SD card programmed from Yocto images:
Disk /dev/sdX: 59.48 GiB, 63864569856 bytes, 124735488 sectors
Disk model: MassStorageClass
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x5ebf1617
Device Boot Start End Sectors Size Id Type
/dev/sdX1 16384 15165439 15149056 7.2G 83 Linux
- At the beginning of the card is 8 MiB of reserved area for the partition table and bootloader.
- The first and only SD card partition begins at offset 16,384 (of 512 byte sectors) which is due to the reserved area explained above. This partition is an ext4 partition that contains the complete root filesystem (including kernel image and device tree files under /boot).
Note: This partition includes an unallocated area to ensure compatibility with all 8 GB SD cards, as their actual sizes may vary. For instructions on optimizing the usage of your SD card's capacity, refer to the section Extending the SD Card Size.
Yocto pre-built bootable SD card¶
The Yocto build products contains many files. For example, var-image-debian-imx8mp-var-dart.wic.zst, depending on your build. This is a complete and bootable image ready to be flashed directly to an SD card.
Example usage:
$ sudo umount /dev/sdX*
$ cd ~/debian_imx8mp_var_dart/build_debian_xwayland
$ zstdcat tmp/deploy/images/imx8mp-var-dart/var-image-debian-imx8mp-var-dart.wic.zst | sudo dd of=/dev/sdX bs=1M conv=fsync
Replace sdX with the right device name. This can be obtained by "dmesg" command on your host Linux PC, after the SD card reader is inserted.
Note: Booting your system from an SD card requires pressing the boot-select button, or switching the relevant DIP switch to "Boot from SD card", according to the relevant start-up guide of your system
Note: If using any of the native .wic.zst images output from Yocto, these will only have a default partition size of slightly less than 8 GB in order to fit on most SD cards. In order to maximize all usable space on the SD card, please see the section on Extending the SD Card Size.
Yocto Recovery Image¶
Beginning in Yocto Langdale, Variscite has released a new recovery Yocto image recipe called "var-recovery-image." This image is used to create a bootable SD card that contains another target image to be programmed to the eMMC. See the Debian Recovery SD card or the more manual Installing Yocto to the SOM's internal storage articles for specifics of installing a recovery image.
Usage:
By default, the recovery image boots fsl-image-gui and contains a fsl-image-gui target image to be programmed to eMMC. You can also specify a different target eMMC image to be embedded in the recovery image by setting this variable in local.conf:
Additionally, the recovery image output file name can be modified by setting something like the following in local.conf:
This is an example of configurations added to local.conf:
VAR_RECOVERY_SD_NAME = "mx8mp-debian-bookworm-6.1.36_2.1.0-v1.1"
VAR_RECOVERY_SD_IMAGE = "recipes-fsl/images/fsl-image-gui-chromium.bb"
VAR_RECOVERY_TARGET_ROOTFS = "fsl-image-gui-chromium"
To create a recovery image, run the following from your Yocto environment:
Using the default configuration, this will produce an output relative to the build folder of "./tmp/deploy/images/imx8mp-var-dart/var-recovery-image-imx8mp-var-dart.wic.zst" that can be flashed to the SD card.
If you set the variables mentioned above, this will produce a recovery image relative to the build folder of "./tmp/deploy/images/imx8mp-var-dart/mx8mp-debian-bookworm-6.1.36_2.1.0-v1.1.wic.zst"
Note: Please see the var-recovery-image recipe source for advanced usages of the recovery image.
Extending the SD Card Size¶
Flashing the default .wic.zst images from Yocto results in a rootfs that does not utilize the entire SD card. This section explains how the SD card can be extended on the build host after flashing.
Procedure:
Begin with an SD card on which you have previously flashed a Yocto .wic.zst image. Ensure the SD card is inserted and the device present (i.e. /dev/sda, /dev/mmcblk0, etc.)
Note: Below replace /dev/sdX with your actual device (i.e. /dev/sda)
Start by running fdisk as below and typing "p" and enter to print current partitions. You should see a layout similar to below but numbers may differ depending on card sizes. Note that the partition starts at 16,384 (bytes offset 16384*512) which is to account for the boot content explained above.
$ sudo fdisk /dev/sdX
Welcome to fdisk (util-linux 2.37.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): p
Disk /dev/sdX: 59.48 GiB, 63864569856 bytes, 124735488 sectors
Disk model: MassStorageClass
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x5ebf1617
Device Boot Start End Sectors Size Id Type
/dev/sdX1 16384 15165439 15149056 7.2G 83 Linux
Next, run the following sequence of commands followed by enter with each step explained with a "-" to the right. Each command/input should be followed by enter:
- d - Delete current partition (1).
- n - Create a new parition.
-
- Empty, hit enter only which will leave default response p for primary partition.
-
- Empty, hit enter only which will leave default response 1 for first partition.
- 16384 - Enter 16384 to begin partition past bootloader section.
-
- Empty, hit enter only which will leave last sector as default which should choose ending size of the SD card.
- N - Answers no to not remove the ext4 signature on the disk
- p - Print output and verify before we write. We should see the starting offset the same and the end expanded to fill the SD card.
- w - Write output to disk
See the full log of the above sequence below:
Command (m for help): d
Selected partition 1
Partition 1 has been deleted.
Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p):
Using default response p.
Partition number (1-4, default 1):
First sector (2048-124735487, default 2048): 16384
Last sector, +/-sectors or +/-size{K,M,G,T,P} (16384-124735487, default 124735487):
Created a new partition 1 of type 'Linux' and of size 59.5 GiB.
Partition #1 contains a ext4 signature.
Do you want to remove the signature? [Y]es/[N]o: N
Command (m for help): p
Disk /dev/sdX: 59.48 GiB, 63864569856 bytes, 124735488 sectors
Disk model: MassStorageClass
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
identifier: 0x5ebf1617
Device Boot Start End Sectors Size Id Type
/dev/sdX1 16384 124735487 124719104 59.5G 83 Linux
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
Finally, the file system needs to be resized on the disk to fill the now larger partition. Do that as follows:
$ sudo e2fsck -f /dev/sdX1
e2fsck 1.46.5 (30-Dec-2021)
root: recovering journal
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
root: 43155/947488 files (0.1% non-contiguous), 674097/1893632 blocks
$ sudo resize2fs /dev/sdX1
resize2fs 1.46.5 (30-Dec-2021)
Resizing the filesystem on /dev/sdX1 to 15589888 (4k) blocks.
The filesystem on /dev/sdX1 is now 15589888 (4k) blocks long.
$ sync
Again, numbers and output should differ slightly depending on your card.
Your rootfs image should now fill the entire SD card and is ready to boot.
Boot the board with a bootable SD card¶
Setting the Boot Mode¶
Make sure the BOOT SELECT DIP switch on the carrier board is set correctly before you power on the board.
Automatic device tree selection in U-Boot¶
We have different kernel device trees, corresponding to our different H/W configurations.
We implemented a script in U-Boot's environment, which sets the fdt_file environment variable based on the detected hardware.
Enable/Disable automatic device tree selection¶
To enable the automatic device tree selection in U-Boot (already enabled by default):
To disable the automatic device tree selection in U-Boot, set the device tree file manually:
Useful example: To list all files in the /boot directory (where the dtb files are by default) of an SD card:
Flash images to NAND/eMMC¶
Please refer to Debian NAND Flash Burning guide.