This topic explains how to boot Digi Embedded Yocto images without updating the firmware on the internal eMMC. This is helpful during the development phase, as it preserves the original firmware on the SOM.
Open a serial connection
You must open a serial connection to communicate with your device.
-
Open a serial connection using any terminal program such as Tera Term, Minicom, Coolterm, or HyperTerminal. This documentation demonstrates using Minicom to work with the device command line.
Use the following settings:
Parameter Value Port
Serial port where the device is connected
Baud rate
115200
Data bits
8
Parity
None
Stop bits
1
Flow control
None
-
Reset the device by pressing the reset button on the board. Then immediately press any key in the serial terminal to stop the auto-boot process. The U-Boot bootloader prompt displays:
U-Boot SPL dub-2024.04-r5.2+g25c8faec2f83+p0 (May 27 2026 - 10:40:43 +0000) SOC: 0xb0009500 LC: 0x40010 SYS Boot reason: por, origin: -1, errid: -1 SYS shutdown reason: por, origin: -1, errid: -1 DDRMIX is powered UP Normal Boot Trying to boot from MMC1 Primary set selected Load image from MMC/SD 0xc9400 NOTICE: BL31: v2.10.0 (release):lf-6.6.52-2.2.2-dirty NOTICE: BL31: Built : 09:57:54, Oct 17 2025 U-Boot dub-2024.04-r5.2+g25c8faec2f83+p0 (May 27 2026 - 10:40:43 +0000) CPU: i.MX95 rev2.0 at 1800MHz CPU: Extended Industrial temperature grade (-40C to 125C) at 28C LM Boot reason: por, origin: -1, errid: -1 LM shutdown reason: por, origin: -1, errid: -1 DRAM: 1.8 GiB Error: ele_read_common_fuse: ret -5, fuse_id 0x139, response 0xbc29 ahab read fuse failed -5, 0xbc29 Cannot read HWID MCA: HW_VER=1 FW_VER=0.09 cfg name not match mx95alt:ccimx95dvk, ignore Core: 303 devices, 36 uclasses, devicetree: separate MMC: FSL_SDHC: 0, FSL_SDHC: 1 Loading Environment from MMC... OK [*]-Video Link 0clk disp1pix already disabled (1280 x 800) [0] display-controller@4b400000, video [1] channel@0, video_bridge [2] bridge@8, video_bridge [3] channel@0, display [4] lvds0_panel, panel In: serial Out: serial Err: serial Model: Digi International ConnectCore 95 DVK ConnectCore 95 SOM variant 0x03: 1.8 GiB LPDDR5, Wi-Fi, Bluetooth ConnectCore 95 SMARC variant 0x03: Dual Ethernet, MCA Board version 2, ID undefined Boot: MMC0 BuildInfo: - SM firmware Build 733, Commit ecd89d0b, May 05 2026 00:00:18 - ELE firmware version 2.0.3-5f1204b7 Error: ele_read_common_fuse: ret -5, fuse_id 0x139, response 0xbc29 ahab read fuse failed -5, 0xbc29 flash target is MMC:0 Net: eth0: enetc-0 [PRIME], eth1: enetc-1 Fastboot: Normal Normal Boot Hit any key to stop autoboot: 0 =>
Boot the system from network
This shows how to transfer the images to the target via TFTP or NFS, and mount an NFS root file system.
| This requires that you set up your PC workstation as explained in Set up native Linux PC. |
1. Prepare the device artifacts
-
Get the Digi Embedded Yocto firmware images to boot from network:
-
The kernel file:
Image.gz-ccimx95-dvk.bin. -
The device tree:
ccimx95-dvk.dtb. -
Any device tree overlays files that apply to your hardware:
<device-tree-overlay-file>.dtbo(see Pre-compiled device tree overlays). -
The compressed root file system:
<rootfs-file>.tar.xz.
-
After building the Digi Embedded Yocto firmware, you can find the image files inside the project directory at
<project_folder>/tmp/deploy/images/ccimx95-dvk. -
You can download Digi-provided pre-built images from XWayland images.
-
-
Untar the root file system tarball (
*.tar.xz) in the NFS exported directory of your development workstation. See Set up native Linux PC.$ sudo tar xvfp <image>.tar.xz -C /exports/nfsroot-ccimx95_dvk -
Copy the kernel
Image.gz-ccimx95-dvk.binfile to the TFTP exported directory of your development workstation.$ sudo cp Image.gz-ccimx95-dvk.bin /tftpboot -
Copy the device tree file to the TFTP exported directory of your development workstation.
$ sudo cp ccimx95-dvk.dtb /tftpboot -
(Optional) Copy any device tree overlay
*.dtbofiles that apply to your variant to the TFTP exported directory of your development workstation.$ sudo cp <device-tree-overlay-file>.dtbo /tftpboot
2. Configure your device’s network settings
-
Get a dynamic IP for your target:
=> setenv autoload no => dhcpor you can set a static IP:
=> setenv ipaddr 192.168.115.222 -
Configure the IP of the development workstation with TFTP and NFS servers installed. See Set up native Linux PC:
=> setenv serverip 192.168.115.1
3. Boot from network
Boot from TFTP+NFS
-
Set the directory with the rootfs to mount. This directory is the one exported via NFS in your development workstation. See Set up an NFS server.
=> setenv rootpath /exports/nfsroot-ccimx95_dvk -
Specify the device tree (
*.dtb) file name. This is the name of the*.dtbfile you copied to the TFTP exported directory of your development workstation.=> setenv fdt_file ccimx95-dvk.dtb -
(Optional) Use a comma-separated list to specify the device tree overlay (
*.dtbo) files you want to apply. These are the names of the*.dtbofiles you copied to the TFTP exported directory of your development workstation.=> setenv overlays <overlay1>.dtbo,<overlay2>.dtbo -
Establish the kernel file name. This is the name of the file you copied to the TFTP exported directory of your development workstation.
=> setenv imagegz Image.gz-ccimx95-dvk.bin -
Save the changes.
=> saveenv -
Boot from TFTP.
=> dboot linux tftpYou can make these changes persistent by writing the following command:
=> setenv bootcmd 'dboot linux tftp' => saveenv
The target now loads the kernel and device tree from the TFTP server and the root file system from the NFS server.
Boot entirely from NFS
To avoid using TFTP for kernel and device tree files and boot everything from NFS, copy the kernel Image.gz-ccimx95-dvk.bin, device tree ccimx95-dvk.dtb and device tree overlay files to the NFS-exported directory of your development workstation (instead of to the TFTP directory).
See Set up an NFS server.
=> dboot linux nfs
Boot from microSD card
U-Boot can start a complete Digi Embedded Yocto system from a microSD card. See Boot from microSD card for instructions on creating a bootable microSD card and booting from it.