The linux partition contains the following elements:

  • The kernel binary.

  • Several device tree blobs for each SOM and carrier board variant.

  • A U-Boot bootscript to boot the system.

    The main purpose of the bootscript is to select the appropriate device tree blob depending on the detected SOM variant and carrier board. This element is provided by the bootloader Yocto recipe, not the kernel.

The linux partition is formatted depending on the storage media:

Media File system





To list the contents of the linux partition on MMC media, run ls mmc x:y in the U-Boot console where x is the device index (starting at 0) and y is the partition index (starting at 1). For example:

=> ls mmc 0:1
  5727600   zimage-ccimx6qpsbc.bin
    54314   zimage-imx6qp-ccimx6qpsbc.dtb
    54425   zimage-imx6qp-ccimx6qpsbc-id160.dtb
    54425   zimage-imx6qp-ccimx6qpsbc-wb.dtb
     1045   boot.scr

5 file(s), 0 dir(s)

To update the files from U-Boot console, run updatefile command. See Update files within partition.

To update the files from user space, mount the linux partition. For that, you need to mount the /dev/mmcblk0p1 device as a vfat file system.

~# mkdir /mnt/linux
~# mount -t vfat /dev/mmcblk0p1 /mnt/linux
~# ls -la /mnt/linux/
drwxr-xr-x    2 root     root         16384 Jan  1  1970 .
drwxr-xr-x    3 root     root          4096 Jan  1  2000 ..
-rwxr-xr-x    1 root     root          1045 Aug 29 21:26 boot.scr
-rwxr-xr-x    1 root     root       5727600 Aug 29 21:26 zImage-ccimx6qpsbc.bin
-rwxr-xr-x    1 root     root         54425 Aug 29 21:26 zImage-imx6qp-ccimx6qpsbc-id160.dtb
-rwxr-xr-x    1 root     root         54425 Aug 29 21:26 zImage-imx6qp-ccimx6qpsbc-wb.dtb
-rwxr-xr-x    1 root     root         54314 Aug 29 21:26 zImage-imx6qp-ccimx6qpsbc.dtb

The linux partition is automatically mounted to /mnt/linux, but as a read-only filesystem. To be able to write on the partition, remount it read/write with mount -o remount,rw /dev/mmcblk0p1 /mnt/linux.

From your development machine, you can now copy the files to the target via ssh. For example:

scp zImage root@<cc6plus-ip>:/mnt/linux/zImage-ccimx6qpsbc.bin

When building from Yocto, all the elements are packaged together in a single file:

  • dey-image-qt-x11-ccimx6qpsbc.boot.vfat or similar on the ConnectCore 6 Plus SBC.

To update the entire linux partition from U-Boot console, save the image file to your TFTP server and use the update command in U-Boot:

=> update linux tftp <filename>