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Linux 4.14, Myon II
  • Ready for review
  • Linux 4.14, Myon II

    http://gitlab.keith-koep.com/imx/linux-imx

    Linux 4.14 based on NXP 4.14.98_2.0.0_ga

    ssh://git@git.seco.com:seco-ne/kernel/linux-imx-kuk.git
    https://git.seco.com/seco-ne/kernel/linux-imx-kuk.git

    kuk_imx_4.14.98_2.0.0_ga

     

    The Myon II is software-compatible with the Trizeps VIII Mini module.
    Because Trizeps VIII, Trizeps VIII Mini, and Myon II share the same kernel source code, you may a look at Linux 4.14, Trizeps VIII (-/Mini/Nano) for instructions on how to build and deploy an image. The only difference is the Device-Tree-Binary (.dtb) file passed to the kernel on boot.

    How to Build Linux Kernel for Myon II

    This is only a quick-reference on how to build a Linux Kernel including Seco specific changes.
    For details please view the Linux and NXP i.MX8M documentation.

    Get the source code of linux-imx from the git repository:

    $ git clone https://git.seco.com/seco-ne/kernel/linux-imx-kuk.git -b kuk_imx_4.14.98_2.0.0_ga

    Setup Cross-Build environment (View Software-Development-Kit on how to install.):

    $ . /opt/fsl-imx-fb/4.14-sumo/environment-setup-aarch64-poky-linux

    Build Linux-Kernel from source code:

    ~/linux-imx$ make ARCH=arm64 defconfig ~/linux-imx$ make

    This will generate linux kernel ('Image') and device-tree binary ('*.dtb') files.

    ~/linux-imx/arch/arm64/boot/Image ~/linux-imx/arch/arm64/boot/dts/keithkoep/*.dtb

    After you generated the kernel, you might want to build the kernel-modules:

    ~/linux-imx$ make modules ~/linux-imx$ make modules_install INSTALL_MOD_PATH=~/linux-imx-modules

    Note: When the kernel boots it loads kernel-modules from the root-filesystem at '/lib/modules/<kernel-build-number>' (i.e. /lib/modules/4.14.78-imx_4.14.78_1.0.0_ga+g66620c3). The kernel-build-number is derived from git.

    Update Kernel

    Updating the kernel involves to copy 'Image' and the kernel-module directory to the device.
    If the kernel-build-version did not change, copy of the kernel-module directory can be omitted.

    Update using USB and bootloader

    Enter the bootloader command console and run:

    u-boot=> ums 0 mmc 0

    This will configure the USB-OTG port to emulate a USB-Mass-Storage device.
    Example:

    $ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 240G 0 disk ├─sda1 8:1 0 232G 0 part / └─sda2 8:2 0 8G 0 part sde 8:64 1 3,8G 0 disk └─sde1 8:65 1 3,8G 0 part /media/imx6/9016-4EF8 sdf 8:80 1 7,1G 0 disk ├─sdf1 8:81 1 500M 0 part /media/imx6/00BA-BF8A └─sdf2 8:82 1 6,6G 0 part /media/imx6/fd195515-0a44-4a7e-9387-bec6087f37ac sr0 11:0 1 1024M 0 rom

    After calling 'ums 0 mmc 0' a new device 'sdf' appears in the list of mounted devices.

    Copy the kernel-'Image' and device-tree binary files to the first partition.

    $ cp ~/linux-imx/arch/arm64/boot/Image /media/imx6/00BA-BF8A/Image $ cp ~/linux-imx/arch/arm64/boot/dts/keithkoep/*.dtb /media/imx6/00BA-BF8A/

    Copy the kernel-modules-directory to the second partition, which contains the root-filesystem.

    cp -r ~/linux-imx-modules/* /media/imx6/fd195515-0a44-4a7e-9387-bec6087f37ac

    Hints on using the Kernel

    Device Tree

    The Linux-kernel will use a Device-Tree-Binary file (.dtb) to determine how the Myon module is used in a system (i.e. which drivers to load). The device-tree files can be found at:

    ~/linux_imx/arch/arm64/boot/dts/keithkoep

    When building the Linux-kernel .dts source-files are converted to .dtb binary files.

    DeviceTree (dtb)

    Module

    Description

    DeviceTree (dtb)

    Module

    Description

    kuk-myon2

    Myon II

    Basic Device-Tree for the Myon II module itself, which is included by all other Device-Tree baseboard files

    kuk-myon2-ipanm7

    Myon II

    Myon II in i-PAN M7 panel

    kuk-myon2-conxm

    Myon II

    Myon II ConXM baseboard

    When you open the u-boot command prompt and output the environment, you can determine which device-tree is used:

    u-boot=> env print -a ... fdt_file=kuk-myon2.dtb ...

    To change this you can call:

    u-boot=> env set fdt_file kuk-myon2-ipanm7.dtb u-boot=> env save

    'env save' will store this setting for subsequent boots.

    Root-Filesystem

    To have a full running Linux-system you will need:

    • Bootloader ( U-Boot, Myon II ), which loads the Device-Tree and Linux-Kernel.

    • Linux Kernel

    • Root-Filesystem, which contains applications, configuration files etc.

    There are different approaches on how to create a root-filesystem.
    Basicly its a linux-distribution like Debian, where the system is put together by packages or like Yocto, where recipes define what needs to be built and put inside the file-system: