Applying any CSI camera overlay (dolphin-*.dtbo) hangs boot on Luna SL1680

Technical Support
1

Board: Toradex Luna SL1680
Torizon OS: 7.5.0-devel-20260123143454+build.0 (scarthgap), refspec
torizon:7/winglet/common-torizon/torizon-docker/testing

I’m trying to bring up an Arducam OV9782 MIPI CSI-2 camera on CSI0 (with the
expander adapter board). v4l2-ctl --list-devices only shows the SoC’s own
ISP/HDMI-in/encoder/decoder nodes (vvcam-video.0.0-3, syna-hrx,
syna-h1-encoder, syna-v4g-vdec) — no sensor subdev, no i2c client for the
sensor.

The image ships with camera overlays already present at
/boot/ostree//dtb/overlays/:
dolphin-bothcsi-without-expander.dtbo
dolphin-csi0-with-expander.dtbo
dolphin-csi1-without-expander.dtbo
dolphin-csi0-with-expander-csi1-without-expander.dtbo

selectable via fdt_overlays=<name>.dtbo in overlays.txt next to them
(empty by default). However, /boot/loader.1/uEnv.txt’s uenv_extra_configs
unconditionally does env set skip_fdt_overlays 1, which disables overlay
application regardless of overlays.txt.

I flipped that flag to 0 (single-line edit) and applied an overlay, and
tested twice with different overlays:

  1. dolphin-csi0-with-expander.dtbo
  2. dolphin-bothcsi-without-expander.dtbo

Both times, on the next boot the board hung completely: power LED on, HDMI
stays black/no signal, unreachable on the network, indefinitely. No serial
console is broken out on this board that I could use to see U-Boot/kernel
output. Only recovery was a full reflash via the USB_BOOT jumper + GCT port

  • flash-image.sh procedure from the getting-started guide, both times.

Since two different overlays produced the identical hang, this doesn’t look
like a bad overlay choice — more like overlay application itself is
broken/unverified on this testing-channel build, and skip_fdt_overlays=1
might be an intentional safety default rather than an oversight.

Questions:

  • Is CSI camera overlay support known-working on a different
    Torizon OS build for the Luna SL1680, or still WIP?
  • Is there a supported way to bring up the OV9782 today (e.g. via
    TorizonCore Builder instead of a raw uEnv.txt edit), or a recommended
    sensor/overlay combination that’s actually been validated?
  • Is there a debug UART/serial console header on this board I’m missing,
    for next time this happens?

Happy to share full dmesg/journalctl output, exact uEnv.txt diff, or
try anything else that’d help narrow this down.

Luna_SL1680

2

Hi, I’m the Toradex AI Assistant.

I might make mistakes or occasionally get you wrong. Our support team will step in if needed.

I don’t have specific information in the available sources about the Luna SL1680 board, CSI camera support on that platform, or the dolphin-*.dtbo overlays you’re encountering. The documentation I have access to covers camera overlays for other Toradex SoM families (Verdin, Apalis, Colibri, Aquila, SMARC) but doesn’t include the Luna SL1680.

Given that you’re running a development/testing build (7.5.0-devel-20260123143454+build.0) from the testing channel, and the fact that skip_fdt_overlays=1 is set by default in uEnv.txt, this strongly suggests that overlay support may still be work-in-progress for this platform.

What I Can Suggest

Since this is outside the scope of the documentation I have access to, I recommend:

  1. Reach out on the Toradex Community by searching for “Luna SL1680” or posting your detailed question there, as this is early-access hardware that may have platform-specific guidance not yet in the general documentation.

  2. Contact Toradex support directly for Luna SL1680-specific guidance, especially since:

    • This appears to be a testing/development build
    • The board may have specific bring-up procedures
    • Serial console access information would be hardware-specific

  3. Check for updated builds on the testing channel that may have resolved overlay application issues

For general context on how camera overlays work on other Toradex platforms, you can reference the [Device Tree Overlays on Torizon](1) and [First Steps with Arducam CSI Camera Module 5MP OV5640 (Torizon)](2) articles, though the specific overlay names and procedures will differ for your platform.

Best regards,
Toradex AI Assistant.

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3

Greetings @tomasaviram,

This is currently a known issue for our team. That is the reason we have skip_fdt_overlays set while our team investigates the issue. For the time being please avoid trying to set device tree overlays on the Luna board.

Best Regards,
Jeremias