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Convert to eLxr

Use this guide to convert an existing SiMa.ai Yocto-based DevKit to the eLxr runtime environment, and to revert to Yocto when needed.

note

The eLxr platform is available starting from SDK 2.0.0 and later on the Modalix DevKit.

Converting to eLxr requires a tRoot update and eMMC reflash facilitated by Net Boot Recovery.

The eLxr platform replaces the legacy Yocto environment as the default runtime for SiMa.ai DevKits. It provides:

  • Simplified updates — unified root filesystem layout with a larger root filesystem.
  • Standard package manager — Debian-based foundation with persistent package management.

Before you migrate, check which firmware the DevKit is running. Connect through serial or SSH and run:

cat /etc/buildinfo | grep DISTRO

You should see either:

DISTRO = poky

or

DISTRO = eLxr

If you see poky, follow the steps below to migrate.

Step 1. Update to the Latest tRoot

Before you convert to eLxr, update the DevKit to the latest tRoot image.

This update makes the tRoot (trusted root) compatible with eLxr.

With the host on static IP 192.168.1.10 and the DevKit reachable at 192.168.1.20 (see network setup):

Run on the host machine
sima-user@sima-user-machine:~$ sima-cli update --ip 192.168.1.20 2.1.2 --troot_only

After the update completes successfully, power cycle the DevKit to apply the changes.

Step 2. Netboot the eLxr Image and Flash the eMMC

The remainder of the conversion uses the standard TFTP netboot + flash procedure documented in Net Boot Recovery. Follow that procedure with the eLxr-specific values below:

  • Step 2 (Start TFTP server): use --boardtype modalix --fwtype elxr -v 2.1.2.
  • Step 3 (Configure U-Boot): set cpio_name=simaai-image-palette-modalix.cpio.gz in addition to boot_targets=net before running boot.
  • Step 4 (Flash): type f at the netboot> prompt.

Connection Diagram

Connection Diagram

After flashing completes and you power-cycle the DevKit, it runs eLxr from eMMC.

Step 3. Optional: Install 2.0 eLxr Out-of-the-box Demo

If your DevKit runs version 1.7, it may include a 1.7-compatible OOB (out-of-the-box) demo. After you convert the DevKit to version 2.0 with eLxr, upgrade the OOB demo with the steps below.

Connect your DevKit to the Internet and access it with SSH or the serial console.

Standalone DevKit

Standalone DevKit

Run on the devkit console shell
modalix:~$ cd /tmp && curl -O https://tools.modalix.info/setup-oob.sh && bash setup-oob.sh

If a previous OOB demo is already installed, the install script prompts you to confirm the upgrade. Type Yes to confirm.

To install the assets, authorize the installation. The install script prints a code and an authorization URL. Open the auth.sima.ai link in a browser, log in with your developer portal credentials, and confirm the code printed in your terminal.

Revert to Yocto (Optional)

To switch back to Yocto, follow Net Boot Recovery again with --fwtype yocto. The cpio_name U-Boot variable is not required for Yocto targets — only setenv boot_targets net, saveenv, boot.

note

There is no minimum tRoot version requirement when converting back to Yocto, so Step 1 above can be skipped.

If NFS-related error messages appear on the serial console after converting to eLxr, they can be safely ignored.

Summary​

  1. Update to the latest tRoot image (≥ 2.0.0).
  2. Follow Net Boot Recovery with --fwtype elxr and the eLxr cpio_name to flash eLxr to eMMC.