Linux Kernel (2018 March MDK Release)¶

Critical Link Kernel Repository¶

Critical Link recommendings using the mityarm-linux-v4.4 branch on our git server: git://support.criticallink.com/home/git/linux-mityarm-335x.git (Gitweb)

Configuring the Kernel Build Environment¶

• Setup the MDK environment (Note: Your SDK path may differ):
  

  source /opt/criticallink/mitysom-335x_2018-03-16/environment-setup-cortexa8hf-neon-criticallink-linux-gnueabi
  

Building the Kernel¶

• Clone the repository from Critical Link:
  

  git clone git://support.criticallink.com/home/git/linux-mityarm-335x.git
  cd linux-mityarm-335x
  git checkout -b linux4.4_rc d14cb2297ba452198c1b19b6e6984b4640aba1a9
  

  
  Note: Commit: d14cb2297ba452198c1b19b6e6984b4640aba1a9 is the commit for the March MDK release. Checking out the origin/linux4.4_rc branch will check out a newer commit not covered by this page.
  Note: You may need to run
  

  git fetch
  

  
  if the branch wasn't cloned.

• Configure the build for the Development Kit Baseboard
  

  make mitysom-335x-devkit_defconfig
  

• Optional: Customize the kernel
  

  make menuconfig
  

• Build the kernel image
  

  make zImage
  

  
  For a faster build, add -j<# threads> to build with multiple threads. Optimally, use as many threads as the building machine has cores.

• Make the kernel modules
  

  make modules
  make INSTALL_MOD_PATH=../rootfs/ modules_install
  

  
  This will build the selected kernel modules and then install them under ../rootfs/. You can change this path to change where the modules will install. For example, you may have the build install directly to an SD card. (Note: Make sure you include the INSTALL_MOD_PATH variable and do not run as root. The kernel Makefile will attempt to install these modules into your machine's root filesystem. You probably do NOT want this!)

• Make device tree blobs (DTB)
  

  make dtbs
  

  
  You will find the compiled DTBs in arch/arm/boot/dts.
  Note: These will be in the same folder as the source files. Make sure to use the .dtb file and not the .dts or .dtsi.

A number of device trees for the devkit are compiled. Use the device tree that matches your SOM variant.

am335x-mitysom-<size of NAND>-NOR.dtb  - SOMs with NOR
am335x-mitysom-<size of NAND>.dtb      - SOMs without NOR
am335x-mitysom.dtb                     - SOM with no NOR or NAND