Yocto Debian Build Release
This page is using the default release mx93-debian-bookworm-6.1.36_2.1.0-v1.0.
To view this page for a specific Variscite SoM and software release, please follow these steps:
- Visit variwiki.com
- Select your SoM
- Select the software release
Installing required packages
Please make sure your host PC is running Ubuntu 20.04/22.04 64-bit and is up to date:
$ sudo apt-get update && sudo apt-get dist-upgrade
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:
$ sudo apt-get install python python-pysqlite2
Starting in Ubuntu 22.04, python2 is no longer available. Install the following to create a symbolic link from python to python3:
$ sudo apt-get install python-is-python3
Setting Up Yocto Build Environment
Configure git user and email:
$ git config --global user.name "Your Name" $ git config --global user.email "Your 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:
$ mkdir ~/debian_imx93_var_som $ cd ~/debian_imx93_var_som
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 $ 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/mx93-debian-bookworm-6.1.36_2.1.0-v1.0 -m $ repo sync -j$(nproc)
Building the Image
After the Yocto environment is set up, you need to configure the build environment for your target device:
$ cd ~/debian_imx93_var_som $ MACHINE=imx93-var-som 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:
$ cd ~/debian_imx93_var_som $ source setup-environment build_debian_xwayland
Then, the image can be created by running the following bitbake command:
$ bitbake var-image-debian
The target rootfs image is located at:
~/debian_imx93_var_som/build_debian_xwayland/tmp/deploy/images/imx93-var-som/var-image-debian-imx93-var-som.wic.gz
Build Results
The resulting images are located in ~/debian_imx93_var_som/build_debian_xwayland/tmp/deploy/images/imx93-var-som.
| Image Name |
How to use |
|---|---|
| var-image-debian-imx93-var-som.wic.zst | This image is for SD card boot. It can be flashed as-is on an SD card that can then be used to boot your system, according to the relevant startup-guide of your product (usually requires to press the boot select button, or toggle a DIP switch). For detailed information refer to the Create a bootable SD card section below. |
| var-image-debian-imx93-var-som.tar.zst | Tarball with rootfs files. Can be used to create an NFS root file system on the host. See the Yocto Setup TFTP/NFS section for more info. Also used to create our extended SD card. See the Create a bootable SD card section below. |
| Image.gz | Linux kernel image, same binary for SD card and eMMC. |
| imx-boot-sd.bin | U-Boot built for SD card boot or eMMC boot. |
| File Name |
Description |
|---|---|
| imx93-var-som-symphony.dtb | Device tree for VAR-SOM-MX93 on Symphony-Board |
| imx93-var-som-symphony-ld.dtb | Device tree for VAR-SOM-MX93 with Low Drive mode on Symphony-Board |
| imx93-var-som-wbe-symphony.dtb | Device tree for VAR-SOM-MX93 with WBE support on Symphony-Board |
| imx93-var-som-wbe-symphony-ld.dtb | Device tree for VAR-SOM-MX93 with Low Drive mode, and WBE support on Symphony-Board |
| imx93-var-som-symphony-m33.dtb | Device tree for VAR-SOM-MX93 with Cortex-M33 on Symphony-Board |
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).
Yocto pre-built bootable SD card
The Yocto build products contains many files as explained in the Build Results section. For example, var-image-debian-imx93-var-som.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_imx93_var_som/build_debian_xwayland $ zstdcat tmp/deploy/images/imx93-var-som/var-image-debian-imx93-var-som.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.
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:
To create a recovery image, simply run the following from your Yocto environment:
~/debian_imx93_var_som/$ bitbake var-recovery-image
This will produce an output relative to the build folder of "./tmp/deploy/images/imx93-var-som/var-recovery-image-imx93-var-som.wic.zst" that can be flashed to the SD card. By default, this 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 VAR_RECOVERY_TARGET_ROOTFS via the command line during build:
i.e.
~/debian_imx93_var_som/$ VAR_RECOVERY_TARGET_ROOTFS="<desired-emmc-image-recipe>" bitbake var-recovery-image
Or alternatively, by setting this variable in local.conf:
~/debian_imx93_var_som/$ VAR_RECOVERY_TARGET_ROOTFS = "<desired-emmc-image-recipe>"
Additionally, the file name of the recovery image output can be modified by setting something like the following in local.conf:
~/debian_imx93_var_som/$ echo 'VAR_RECOVERY_SD_NAME = "mx93-debian-bookworm-6.1.36_2.1.0-v1.0"' >> conf/local.conf
Would produce a recovery image relative to the build folder of "./tmp/deploy/images/imx93-var-som/mx93-debian-bookworm-6.1.36_2.1.0-v1.0.wic.zst"
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.)
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.