Convert to eLxr

This guide explains how to convert an existing SiMa.ai Yocto-based DevKit to the new eLxr runtime environment, and how to revert back 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 netboot.

The eLxr platform replaces the legacy Yocto environment as the new default runtime for SiMa.ai DevKits. It offers significant benefits for developers:

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

To confirm your current environment before migrating, follow the quick check below.

To determine which firmware the DevKit is currently running, connect via 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 proceeding with the eLxr conversion, update the DevKit to the latest tRoot image.

This update is required to ensure that the tRoot (trusted root) is 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):

sima-user@sima-user-machine:~$ sima-cli update --ip 192.168.1.20 2.0.0 --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 Update with Net Boot. Follow that procedure with the eLxr-specific values below:

• Step 2 (Start TFTP server): use --boardtype modalix --fwtype elxr -v 2.0.0.
• 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

Once flashing completes and you power-cycle the DevKit, it will be running eLxr natively from eMMC.

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

Your DevKit running version 1.7 may be preloaded with a 1.7-compatible OOB (out-of-the-box) demo. After converting the DevKit to version 2.0 with eLxr, you can upgrade the OOB demo by following the instructions below.

To proceed, connect your DevKit to the Internet and access it using either an SSH session or the serial console.

Standalone DevKit

modalix:~$ cd /tmp && curl -O https://tools.modalix.info/setup-oob.sh && bash setup-oob.sh

During the install script, if you already have a previous version of the OOB experience installed, you will be prompted to confirm whether you want to upgrade the demo. Type Yes to confirm.

To install the assets, you must authorize the installation. The install script will print a code and an authorization URL during the installation command. Open a browser, navigate to the auth.sima.ai link, and log in with your developer portal credentials. Confirm the code printed in your terminal to authorize the installation.

Revert to Yocto (Optional)

To switch back to Yocto, follow Update with Net Boot 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 Update with Net Boot with --fwtype elxr and the eLxr cpio_name to flash eLxr to eMMC.