The linux partition contains the following elements:

  • The kernel binary.

  • Device tree blobs and overlays.

  • A U-Boot bootscript to boot the system.

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

The linux partition is formatted in FAT file system.

Update files from U-Boot

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
  9906645   Image.gz-ccimx8x-sbc-pro.bin
   135527   ccimx8x-sbc-pro.dtb
      540   _ov_board_flexcan1_ccimx8x-sbc-pro.dtbo
      964   _ov_board_hsd101pfw2-lvds_ccimx8x-sbc-pro.dtbo
      467   _ov_board_lpuart3_ccimx8x-sbc-pro.dtbo
     1529   _ov_board_lt9812-hdmi-dsi0_ccimx8x-sbc-pro.dtbo
     1497   _ov_board_lvds1_ccimx8x-sbc-pro.dtbo
      729   _ov_board_parallel-camera_ccimx8x-sbc-pro.dtbo
     1050   _ov_board_pcie-card_ccimx8x-sbc-pro.dtbo
     1132   _ov_board_pcie-modem_ccimx8x-sbc-pro.dtbo
      731   _ov_board_user-leds_ccimx8x-sbc-pro.dtbo
     1074   _ov_board_v1-v3_ccimx8x-sbc-pro.dtbo
      712   _ov_som_bt_ccimx8x.dtbo
      530   _ov_som_mca-keypad_ccimx8x.dtbo
     2791   _ov_som_quad_ccimx8x.dtbo
      808   _ov_som_wifi_ccimx8x.dtbo
     2490   boot.scr

17 file(s), 0 dir(s)

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

Update files from Linux

The linux partition is automatically mounted to /mnt/linux, but as a read-only filesystem.

To list the contents of the linux partition:

~# ls -l /mnt/linux
-rwxr-xr-x    1 root     root       9901398 Mar  1 01:54 Image.gz-ccimx8x-sbc-pro.bin
-rwxr-xr-x    1 root     root           540 Mar  1 01:54 _ov_board_flexcan1_ccimx8x-sbc-pro.dtbo
-rwxr-xr-x    1 root     root           964 Mar  1 01:54 _ov_board_hsd101pfw2-lvds_ccimx8x-sbc-pro.dtbo
-rwxr-xr-x    1 root     root           467 Mar  1 01:54 _ov_board_lpuart3_ccimx8x-sbc-pro.dtbo
-rwxr-xr-x    1 root     root          1529 Mar  1 01:54 _ov_board_lt9812-hdmi-dsi0_ccimx8x-sbc-pro.dtbo
-rwxr-xr-x    1 root     root          1497 Mar  1 01:54 _ov_board_lvds1_ccimx8x-sbc-pro.dtbo
-rwxr-xr-x    1 root     root           729 Mar  1 01:54 _ov_board_parallel-camera_ccimx8x-sbc-pro.dtbo
-rwxr-xr-x    1 root     root          1050 Mar  1 01:54 _ov_board_pcie-card_ccimx8x-sbc-pro.dtbo
-rwxr-xr-x    1 root     root          1132 Mar  1 01:54 _ov_board_pcie-modem_ccimx8x-sbc-pro.dtbo
-rwxr-xr-x    1 root     root           731 Mar  1 01:54 _ov_board_user-leds_ccimx8x-sbc-pro.dtbo
-rwxr-xr-x    1 root     root          1074 Mar  1 01:54 _ov_board_v1-v3_ccimx8x-sbc-pro.dtbo
-rwxr-xr-x    1 root     root           712 Mar  1 01:54 _ov_som_bt_ccimx8x.dtbo
-rwxr-xr-x    1 root     root           530 Mar  1 01:54 _ov_som_mca-keypad_ccimx8x.dtbo
-rwxr-xr-x    1 root     root          2791 Mar  1 01:54 _ov_som_quad_ccimx8x.dtbo
-rwxr-xr-x    1 root     root           808 Mar  1 01:54 _ov_som_wifi_ccimx8x.dtbo
-rwxr-xr-x    1 root     root          2490 Mar  1 01:54 boot.scr
-rwxr-xr-x    1 root     root        135527 Mar  1 01:54 ccimx8x-sbc-pro.dtb

To update the files from user space, remount the linux partition with read/write permissions:

~$ 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 Image.gz root@<cc8x-ip>:/mnt/linux/Image.gz-ccimx8x-sbc-pro.bin

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

  • dey-image-qt-xwayland-ccimx8x-sbc-pro.boot.vfat or similar on the ConnectCore 8X SBC Pro.

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>