byteDEVKIT-imx8mm (Yocto 5.0)

Downloads

SD card image

Download

Checksum (SHA256)

bytesatwork-minimal-image-bytedevkit-imx8mm.rootfs.wic.gz

6ac5c8ff619a1425afb1c9bf1f85c4067fb90473a895448df5eb7d30e0495c9d

bytesatwork-minimal-image-bytedevkit-imx8mm.rootfs.wic.bmap

78d9bb5dbdbb7abdb7f0d2444c47401d2dea229e88ee1e794b8e728a88a5ea85

Toolchain

Download

Checksum (SHA256)

poky-bytesatwork-glibc-x86_64-bytesatwork-minimal-image-cortexa53-crypto-bytedevkit-imx8mm-toolchain-5.0.5.sh

793bada77eb0a3fb43fcc1c3148e883621bfcb3bcbadac43e3646cf6a5d7047f

U-Boot

Description

Download

Checksum (SHA256)

U-Boot (SD-card)

imx-boot-bytedevkit-imx8mm-sd.bin-flash_evk

47b228b3df345ec47aff9e4eb3b9611e43d041fe2aa0557fd11fccca8b9c5e82

Image

How do you flash the image?

Attention

  • You need a microSD card with at least 8GB capacity.

  • All existing data on the microSD card will be lost.

  • Do not format the microSD card before flashing.

Windows

  1. Unzip the file bytesatwork-minimal-image-bytedevkit-imx8mm.rootfs.wic.gz (e.g. with 7-zip)

  2. Write the resulting file to the microSD card with a tool like Roadkils Disk Image

Linux

gunzip -c bytesatwork-minimal-image-bytedevkit-imx8mm.rootfs.wic.gz | dd of=/dev/mmcblk<X> bs=8M conv=fsync status=progress

Hint

To improve write performance, you could use bmap-tools under Linux:

bmaptool copy bytesatwork-minimal-image-bytedevkit-imx8mm.rootfs.wic.gz /dev/mmcblk<X>

How do you build an image?

Use repo to download all necessary repositories:

$ mkdir -p ~/workdir/bytedevkit-imx8mm/5.0; cd ~/workdir/bytedevkit-imx8mm/5.0
$ repo init -b scarthgap-imx8mm -u https://github.com/bytesatwork/bsp-platform-nxp.git
$ repo sync

If those commands are completed successfully, the following command will set up a Yocto Project environment for byteDEVKIT-imx8mm:

$ cd ~/workdir/bytedevkit-imx8mm/5.0
$ MACHINE=bytedevkit-imx8mm DISTRO=poky-bytesatwork EULA=1 . setup-environment build

The final command builds the development image:

$ cd $BUILDDIR
$ bitbake bytesatwork-minimal-image

The output is found in:

~/workdir/bytedevkit-imx8mm/5.0/build/tmp/deploy/images/bytedevkit-imx8mm

Hint

For additional information about yocto images and how to build them, please visit: https://docs.yoctoproject.org/5.0.5/brief-yoctoprojectqs/index.html#building-your-image.

How to modify the image

The image recipes can be found in ~/workdir/bytedevkit-imx8mm/5.0/sources/meta-bytesatwork/recipes-core/images

This is relative to where you started the repo command to fetch all the sources.

Edit the minimal-image recipe bytesatwork-minimal-image.bb

Add the desired software-package to IMAGE_INSTALL variable, for example add net-tools to bytesatwork-minimal-image.bb

Rebuild the image by:

$ cd ~/workdir/bytedevkit-imx8mm/5.0
$ MACHINE=bytedevkit-imx8mm DISTRO=poky-bytesatwork EULA=1 . setup-environment build
$ bitbake bytesatwork-minimal-image

How to rename the image

If you want to rename or copy an image, simply rename or copy the image recipe by:

$ cd ~/workdir/bytedevkit-imx8mm/5.0/sources/meta-bytesatwork/recipes-core/images
$ cp bytesatwork-minimal-image.bb customer-example-image.bb

Troubleshooting

  • Image size is too small

    If you encounter that your image size is too small to install additional software, please have a look at the IMAGE_ROOTFS_SIZE variable under ~/workdir/bytedevkit-imx8mm/5.0/sources/meta-bytesatwork/recipes-core/images/bytesatwork-minimal-image.bb. Increase the size if necessary.

Toolchain

How do you install the toolchain?

Simply download the toolchain and execute the downloaded file, which is a self-extracting shell script.

Hint

If you encounter problems when trying to install the toolchain, make sure the downloaded toolchain is executable. Run chmod +x /<path>/<toolchain-file>.sh to make it executable.

Important

The following tools need to be installed on your development system:

  • xz (Debian package: xz-utils)

  • python (any version)

  • gcc

How do you use the toolchain?

Source the installed toolchain:

source /opt/poky-bytesatwork/5.0.5/environment-setup-cortexa53-crypto-poky-linux

Check if Cross-compiler is available in environment:

echo $CC

You should see the following output:

aarch64-poky-linux-gcc -mcpu=cortex-a53+crc+crypto -mbranch-protection=standard -fstack-protector-strong -O2 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Werror=format-security --sysroot=/opt/poky-bytesatwork/5.0.5/sysroots/cortexa53-crypto-poky-linux

Crosscompile the source code, e.g. by:

$CC helloworld.c -o helloworld

Check generated binary:

file helloworld

The output that is shown in prompt afterwards:

helloworld: ELF 64-bit LSB pie executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-aarch64.so.1, BuildID[sha1]=6724ab4b61feda872c2488c7c4f73ca960cdba8b, for GNU/Linux 5.15.0, with debug_info, not stripped

How to bring your binary to the target?

  1. Connect the embedded device’s ethernet to your LAN

  2. Determine the embedded target IP address by ip addr show

https://www.bytesatwork.io/wp-content/uploads/2020/05/ip_addr_show_28.png

  1. Copy your binary, e.g. helloworld to the target by scp helloworld root@<ip address of target>:/tmp

https://www.bytesatwork.io/wp-content/uploads/2020/05/scp2.png

  1. Run chmod +x on the target to make your binary executable: chmod +x /<path>/<binary name>

  2. Run your binary on the target: /<path>/<binary name>

How do you build a toolchain?

$ cd ~/workdir/bytedevkit-imx8mm/5.0
$ repo init -b scarthgap-imx8mm -u https://github.com/bytesatwork/bsp-platform-nxp.git
$ repo sync

If those commands are completed successfully, the following command will set up a Yocto Project environment for byteDEVKIT-imx8mm:

$ cd ~/workdir/bytedevkit-imx8mm/5.0
$ MACHINE=bytedevkit-imx8mm DISTRO=poky-bytesatwork EULA=1 . setup-environment build

The final command builds an installable toolchain:

$ cd $BUILDDIR
$ bitbake bytesatwork-minimal-image -c populate_sdk

The toolchain is located under:

~/workdir/bytedevkit-imx8mm/5.0/build/tmp/deploy/sdk

How to modify your toolchain

Currently the bytesatwork toolchain is generated out of the bytesatwork-minimal-image recipe. If you want to add additional libraries and development headers to customize the toolchain, you need to modify the bytesatwork-minimal-image recipe. It can be found under ~/workdir/bytedevkit-imx8mm/5.0/sources/meta-bytesatwork/recipes-core/images

For example: if you want to develop your own application utilizing CAN communication and need libsocketcan and the corresponding header files, edit the recipe bytesatwork-minimal-image.bb and add libsocketcan to the IMAGE_INSTALL variable.

This will provide the libsocketcan libraries and development headers in the toolchain. After adding additional software components, the toolchain needs to be rebuilt by:

$ cd ~/workdir/bytedevkit-imx8mm/5.0
$ MACHINE=bytedevkit-imx8mm DISTRO=poky-bytesatwork EULA=1 . setup-environment build
$ bitbake bytesatwork-minimal-image -c populate_sdk

The newly generated toolchain will be available under:

~/workdir/bytedevkit-imx8mm/5.0/build/tmp/deploy/sdk

For additional information, please visit: https://docs.yoctoproject.org/5.0.5/overview-manual/concepts.html#cross-development-toolchain-generation.

Kernel

Download the Linux Kernel

Device

Branch

git URL

bytedevkit-imx8mm

baw-lf-6.1.55-2.2.1-imx8mm

https://github.com/bytesatwork/linux-imx.git

Build the Linux Kernel

For both targets, an ARM toolchain is necessary. You can use the provided toolchain from Toolchain or any compatible toolchain (e.g. from your distribution)

Important

The following tools need to be installed on your development system:

  • git

  • make

  • bc

Note

The following instructions assume, you installed the provided toolchain for the respective target.

Important

The following tools need to be installed on your development system:

  • OpenSSL headers (Debian package: libssl-dev)

  • depmod (Debian package: kmod)

  1. Download kernel sources

    Download the appropriate kernel from Download the Linux Kernel.

  2. Source toolchain

    source /opt/poky-bytesatwork/5.0.5/environment-setup-cortexa53-crypto-poky-linux

  3. Create defconfig

    make bytedevkit_imx8mm_defconfig

  4. Build Linux kernel

    make -j `nproc` Image dtbs modules

  5. Install kernel and device tree

    To use the newly created kernel, device tree and/or module, the necessary files need to be installed on the target. This can be done either via Ethernet (e.g. scp) or by copying the files to the SD card.

    Note

    For scp installation: Don’t forget to mount /boot on the target.

    File

    Target path

    Target partition

    arch/arm64/boot/Image

    /boot/Image

    /dev/mmcblk1p1

    arch/arm64/boot/dts/freescale/imx8mm-bytedevkit.dtb

    /boot/imx8mm-bytedevkit.dtb

    /dev/mmcblk1p1

    Note

    After installing a new kernel, it often fails to load modules, as the _signature_ of the kernel changed and it fails to find its corresponding modules folder. This issue can often be resolved with a symlink:

    ln -s /lib/modules/<EXISTING FOLDER> /lib/modules/`uname -r`

    Otherwise, please follow the instructions to copy the kernel modules

  6. Install kernel modules

    To copy all available modules to the target, it’s best to deploy them locally first and then copy all modules to the target.

    mkdir /tmp/bytedevkit-imx8mm
make INSTALL_MOD_PATH=/tmp/bytedevkit-imx8mm modules_install

Now you can copy the content of the folder /tmp/bytedevkit-imx8mm into the target’s root folder (/) which is partition /dev/mmcblk1p1.

U-Boot

Additional information can be found under https://www.nxp.com/docs/en/user-guide/IMX_LINUX_USERS_GUIDE.pdf and https://docs.u-boot.org/en/latest/board/nxp/index.html.

Note

On i.MX 8M Mini, SPL and U-Boot are combined in a container file called flash.bin (Yocto: imx-boot-bytedevkit-imx8mm-sd.bin-flash_evk).

Download U-Boot Source Code

Device

Branch

git URL

bytedevkit-imx8mm

baw-lf_v2024.04-imx8mm

https://github.com/bytesatwork/u-boot-imx

Install SPL and U-Boot

To use the newly created U-Boot, the necessary file needs to be installed on the SD card. This can be done either on the host or on the target.

File

Target partition

Offset

flash.bin

Yocto: imx-boot-bytedevkit-imx8mm-sd.bin-flash_evk

/dev/mmcblk1 (or /dev/sdX)

33 KiB

You need to write the files to the respective “raw” partition, either on the host system or the target system:

dd if=./u-boot-imx/flash.bin of=/dev/mmcblk1 bs=1K seek=33

The next time the target is reset, it will start with the new U-Boot.

Note

Flash to SPI

  1. Copy flash.bin to first SD card partition (root partition)

  2. You need to boot into u-boot.

  3. In the u-boot shell: run update-spi

  4. Or do it manually by

    sf probe; sf erase 0 0x200000; load mmc 1:1 ${loadaddr} flash.bin; sf write $loadaddr 0 $filesize
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