byteDEVKIT-am62x (Yocto 4.0)

Downloads

SD card image

Download	Checksum (SHA256)
bytesatwork-minimal-image-bytedevkit-am62x.wic.gz	0747dfb463edad01cd3bf7985bed602e717b1dfa2f09258ed6860c37b57c67cb
bytesatwork-minimal-image-bytedevkit-am62x.wic.bmap	3577b6bc71600903fcba120629a50f5595e25f9ceb63d6301efb3f46d3848115

Hint

Updating from an older image? You can update your older image by using: apt-get update and apt-get upgrade.

1. check for new version in the table above

2. edit /etc/apt/sources.list and point to the new package feed

3. run apt-get update; apt-get upgrade

As the yocto framework is based on several packages from various projects or suppliers, it is not guaranteed that an incremental upgrade by apt-get upgrade works automatically. Some manual adjustments might be needed.

Toolchain

Download	Checksum (SHA256)
poky-bytesatwork-glibc-x86_64-bytesatwork-minimal-image-aarch64-bytedevkit-am62x-toolchain-4.0.9.sh	a5e9e6706cbff94fb3e31b41e948cbe1665cabca457e1bf337c59d45d6616c82

U-Boot

Description	Download	Checksum (SHA256)
SPL R5F	tiboot3.bin	53481b110634d711c43c47db40b2cfbce8b993cc6b63892d204d6563f35ea690
SPL A53	tispl.bin	ee581879fba5a58dc872395eda734e5fe4d5bfdc4a4eb48b7e09b21991827908
U-Boot A53	u-boot.img	7c14d88c61772c3bb36d4d1441eee46f3d64f4d5d5abbb1b0ba2a264247a20aa

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-am62x.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-am62x.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-am62x.wic.gz /dev/mmcblk<X>

---

How do you build an image?

Use repo to download all necessary repositories:

$ mkdir -p ~/workdir/bytedevkit-am62x/4.0; cd ~/workdir/bytedevkit-am62x/4.0
$ repo init -b kirkstone -u https://github.com/bytesatwork/bsp-platform-ti.git
$ repo sync

If those commands are completed successfully, the following command will set up a Yocto Project environment for byteDEVKIT-am62x:

$ cd ~/workdir/bytedevkit-am62x/4.0
$ MACHINE=bytedevkit-am62x 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-am62x/4.0/build/tmp/deploy/images/bytedevkit-am62x

Hint

For additional information about yocto images and how to build them, please visit: https://docs.yoctoproject.org/4.0.9/brief-yoctoprojectqs/index.html#building-your-image.

How to modify the image

The image recipes can be found in ~/workdir/bytedevkit-am62x/4.0/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-am62x/4.0
$ MACHINE=bytedevkit-am62x 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-am62x/4.0/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-am62x/4.0/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/4.0.9/environment-setup-aarch64-poky-linux

Check if Cross-compiler is available in environment:

echo $CC

You should see the following output:

aarch64-poky-linux-gcc -fstack-protector-strong -O2 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Werror=format-security --sysroot=/opt/poky-bytesatwork/4.0.9_bytedevkit-am62x/sysroots/aarch64-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]=257792938c3ed4fbf6b15d071c60973ab51b2f37, for GNU/Linux 3.14.0, 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

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

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

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

---

How do you build a toolchain?

$ cd ~/workdir/bytedevkit-am62x/4.0
$ repo init -b kirkstone -u https://github.com/bytesatwork/bsp-platform-ti.git
$ repo sync

If those commands are completed successfully, the following command will set up a Yocto Project environment for byteDEVKIT-am62x:

$ cd ~/workdir/bytedevkit-am62x/4.0
$ MACHINE=bytedevkit-am62x 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-am62x/4.0/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-am62x/4.0/sources/meta-bytesatwork/recipes-core/images

For example if you want to develop your own ftp client and you need libftp and the corresponding header files, edit the recipe bytesatwork-minimal-image.bb and add ftplib to the IMAGE_INSTALL variable.

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

$ cd ~/workdir/bytedevkit-am62x/4.0
$ MACHINE=bytedevkit-am62x 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-am62x/4.0/build/tmp/deploy/sdk

For additional information, please visit: https://docs.yoctoproject.org/4.0.9/overview-manual/concepts.html#cross-development-toolchain-generation.

Kernel

Download the Linux Kernel

Device	Branch	git URL
bytedevkit-am62x	baw-ti-linux-6.1.y	https://github.com/bytesatwork/ti-linux-kernel

---

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/4.0.9/environment-setup-aarch64-poky-linux
   

3. Create defconfig

   make bytedevkit_am62x_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/mmcblk1p2
   arch/arm64/boot/dts/ti/k3-am625-bytedevkit.dtb	/boot/k3-am62x-bytedevkit.dtb	/dev/mmcblk1p2

   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-am62x
   make INSTALL_MOD_PATH=/tmp/bytedevkit-am62x modules_install
   

Now you can copy the content of the folder /tmp/bytedevkit-am62x into the target’s root folder (/) which is partition /dev/mmcblk1p2.

U-Boot

Download U-Boot Source Code

Device	Branch	git URL
bytedevkit-am62x	baw-ti-u-boot-2023.04	https://github.com/bytesatwork/u-boot-ti

---

Build U-Boot

1. Install and get Dependencies

   • Cross toolchain

   • TI-linux-firmware

   • TF-A

   • OP-TEE

   Hint

   Probably some tools are missing on your host:

   • A list can be found here https://docs.u-boot.org/en/latest/build/gcc.html#building-with-gcc

   • A non-exhaustive list of (additional) necessary tools

     sudo apt install bison flex swig libssl-dev python3-setuptools \
     python-dev python3-dev python3-yaml python3-jsonschema
     

2. Build TF-A

   TI TF-A build instructions

3. Build OP-TEE

   TI OP-TEE build instructions

4. Build u-boot

   You should have downloaded TI-linux-firmware and built TF-A, OP-TEE OS already.

   TI u-boot build instructions

   Important

   Use am62x_bytedevkit_r5_defconfig and am62x_bytedevkit_a53_defconfig instead of the TI defconfigs.

   Note

   Clean command: make ARCH=arm CROSS_COMPILE=aarch64-linux-gnu- O=<your_dir> distclean

Install SPL and U-Boot

SD Card

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

File	Target partition	Target partition label	File system
tiboot3.bin tispl.bin u-boot.img	/dev/mmcblk1p1 (or /dev/sdX)	boot	FAT32

You need to copy the files to the boot partition. The example assumes that the boot partition is mounted on /media/${USER}/boot:

cp tiboot3.bin tispl.bin u-boot.img /media/${USER}/boot/

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

Hint

Copy the related files to SD card, see end of section TI u-boot build instructions

eMMC via SD Card

1. Copy the tiboot3.bin, tispl.bin and u-boot.img to the SD Card rootfs partition.

2. Program the tiboot3.bin, tispl.bin and u-boot.img from the SD card to the eMMC.

   In the u-boot shell run update_emmc

   Or manually by following commands

   mmc dev 0 1
   load mmc 1:2 ${loadaddr} tiboot3.bin
   mmc write ${loadaddr} 0x0 0x400
   load mmc 1:2 ${loadaddr} tispl.bin
   mmc write ${loadaddr} 0x400 0xC00
   load mmc 1:2 ${loadaddr} u-boot.img
   mmc write ${loadaddr} 0x1000 0x1000
   mmc dev 0 0
   

Note

The bootloader needs to be stored in the boot0 hardware partition of the eMMC. The layout of boot0 is defined so that it fits within 4 MiB, defined in blocks of 512 Bytes:

File	start	end	size
tiboot3.bin	0x0000	0x0400	0x0400 512 KiB
tispl.bin	0x0400	0x1000	0x0C00 1536 KiB
u-boot.img	0x1000	0x2000	0x1000 2048 KiB