############################# byteDEVKIT-am335x (Yocto 3.1) ############################# ***** Image ***** Where do you get the SD card image? =================================== .. list-table:: :header-rows: 1 * - Device - Yocto Version - Download - Checksum (SHA256) * - bytedevkit-am335x - Yocto 3.1.3 - `bytesatwork-minimal-image-bytedevkit-am335x.wic.gz `_ (`wic.bmap `__) - d1429b5f68808450538d6354d7f40898828c73ef1079092d23663925dce79766 .. Hint:: Updating from an older image? You can update your older image by using: ``apt-get update`` and ``apt-get upgrade``. #. check for new version in the table above #. edit ``/etc/apt/sources.list`` and point to the new package feed #. 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. ---- 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 #. Unzip the file ``bytesatwork-minimal-image-bytedevkit-am335x.wic.gz`` (e.g. with 7-zip) #. Write the resulting file to the microSD card with a tool like `Roadkils Disk Image `_ Linux :: gunzip -c bytesatwork-minimal-image-bytedevkit-am335x.wic.gz | dd of=/dev/mmcblk bs=8M conv=fdatasync status=progress .. Hint:: To improve write performance, you could use bmap-tools under Linux: ``bmaptool copy bytesatwork-minimal-image-bytedevkit-am335x.wic.gz /dev/mmcblk`` ---- How do you build an image? ========================== Use ``repo`` to download all necessary repositories: :: $ mkdir -p ~/workdir/bytedevkit-am335x/3.1; cd ~/workdir/bytedevkit-am335x/3.1 $ repo init -u https://github.com/bytesatwork/bsp-platform-ti.git -b dunfell $ repo sync If those commands are completed successfully, the following command will set up a Yocto Project environment for byteDEVKIT-am335x: :: $ cd ~/workdir/bytedevkit-am335x/3.1 $ MACHINE=bytedevkit-am335x 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-am335x/3.1/build/tmp/deploy/images/bytedevkit-am335x .. Hint:: For additional information about yocto images and how to build them, please visit: https://www.yoctoproject.org/docs/3.1/mega-manual/mega-manual.html#brief-building-your-image How to modify the image ----------------------- The image recipes can be found in ``~/workdir///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// $ MACHINE= 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///build/tmp/deploy/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///sources/meta-bytesatwork/recipes-core/images/bytesatwork-minimal-image.bb``. Increase the size if necessary. ---- ********* Toolchain ********* .. _get-toolchain-bytedevkit-am335x-3.1: Where do you get the toolchain? =============================== .. list-table:: :header-rows: 1 * - Device - Yocto Version - Download - Checksum (SHA256) * - bytedevkit-am335x - Yocto 3.1.3 - `poky-bytesatwork-glibc-x86_64-bytesatwork-minimal-image-armv7at2hf-neon-bytedevkit-am335x-toolchain-3.1.3.sh `_ - 8f36974f1635022a1744f0dfde9c3810fcd1a44422afdad0d3884b79a07aecf3 ---- 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 //.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/3.1.3/environment-setup-armv7at2hf-neon-poky-linux-gnueabi Check if Cross-compiler is available in environment: :: echo $CC You should see the following output: :: arm-poky-linux-gnueabi-gcc -march=armv7-a -mthumb -mfpu=neon -mfloat-abi=hard -fstack-protector-strong -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Werror=format-security --sysroot=/opt/poky-bytesatwork/3.1.3/sysroots/armv7at2hf-neon-poky-linux-gnueabi 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 32-bit LSB pie executable, ARM, EABI5 version 1 ---- 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`` .. image:: https://www.bytesatwork.io/wp-content/uploads/2020/05/ip_addr_show_28.png :scale: 100% :align: center 3. Copy your binary, e.g. ``helloworld`` to the target by ``scp helloworld root@:/tmp`` .. image:: https://www.bytesatwork.io/wp-content/uploads/2020/05/scp2.png :scale: 100% :align: center 4. Run ``chmod +x`` on the target to make your binary executable: ``chmod +x //`` 5. Run your binary on the target: ``//`` ---- How do you build a toolchain? ============================= :: $ cd ~/workdir/bytedevkit-am335x/3.1 $ repo init -u https://github.com/bytesatwork/bsp-platform-ti.git -b dunfell $ repo sync If those commands are completed successfully, the following command will set up a Yocto Project environment for byteDEVKIT-am335x: :: $ cd ~/workdir/bytedevkit-am335x/3.1 $ MACHINE=bytedevkit-am335x 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-am335x/3.1/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///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// $ MACHINE= DISTRO=poky-bytesatwork EULA=1 . setup-environment build $ bitbake bytesatwork-minimal-image -c populate_sdk The newly generated toolchain will be available under: :: ~/workdir///build/tmp/deploy/sdk For additional information, please visit: https://www.yoctoproject.org/docs/3.1/overview-manual/overview-manual.html#cross-development-toolchain-generation ****** Kernel ****** .. _download-kernel-bytedevkit-am335x-3.1: Download the Linux Kernel ========================= .. list-table:: :header-rows: 1 * - Device - Branch - git URL * - bytedevkit-am335x - baw-ti-linux-5.4.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 :ref:`get-toolchain-bytedevkit-am335x-3.1` 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``) * ``mkimage`` (Debian package: ``u-boot-tools``) #. Download kernel sources Download the appropriate kernel from :ref:`download-kernel-bytedevkit-am335x-3.1`. #. Source toolchain :: source /opt/poky-bytesatwork/3.1.3/environment-setup-armv7at2hf-neon-poky-linux-gnueabi #. Create defconfig :: make multi_v7_defconfig #. Build Linux kernel :: make LOADADDR=0x80008000 -j `nproc` uImage am335x-bytedevkit.dtb modules #. 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. .. list-table:: :header-rows: 1 * - File - Target path - Target partition * - ``arch/arm/boot/uImage`` - ``/boot/uImage`` - ``/dev/mmcblk0p4`` * - ``arch/arm/boot/dts/am335x-bytedevkit.dtb`` - ``/boot/am335x-bytedevkit.dtb`` - ``/dev/mmcblk0p4`` .. 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/ /lib/modules/`uname -r` Otherwise, please follow the instructions to copy the kernel modules #. 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-am335x make INSTALL_MOD_PATH=/tmp/bytedevkit-am335x modules_install Now you can copy the content of the folder ``/tmp/bytedevkit-am335x`` into the target's root folder (``/``) which is partition ``/dev/mmcblk0p5``. .. This is the footer, don't edit after this .. image:: ../../images/wiki_footer.jpg :align: center :target: https://www.bytesatwork.io