Talos disk image for the Raspberry Pi generic should in theory work for the boards supported by u-boot rpi_arm64_defconfig. This has only been officialy tested on the Raspberry Pi 4 and community tested on one variant of the Compute Module 4 using Super 6C boards. If you have tested this on other Raspberry Pi boards, please let us know.

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Video Walkthrough

To see a live demo of this writeup, see the video below:

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Prerequisites

You will need
  • talosctl
  • an SD card
Download the latest talosctl. 
curl -sL 'https://www.talos.dev/install' | bash

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Updating the EEPROM

Use Raspberry Pi Imager to write an EEPROM update image to a spare SD card. Select Misc utility images under the Operating System tab. Remove the SD card from your local machine and insert it into the Raspberry Pi. Power the Raspberry Pi on, and wait at least 10 seconds. If successful, the green LED light will blink rapidly (forever), otherwise an error pattern will be displayed. If an HDMI display is attached to the port closest to the power/USB-C port, the screen will display green for success or red if a failure occurs. Power off the Raspberry Pi and remove the SD card from it.
Note: Updating the bootloader only needs to be done once.

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Download the Image

Note: if you need to enable Broadcom VideoCore GPU support, generate a new image from the Image Factory with the correct config.txt configuration and vc4 system extension. More information can be found under the Image Factory Example below.
The default schematic id for “vanilla” Raspberry Pi generic image is ee21ef4a5ef808a9b7484cc0dda0f25075021691c8c09a276591eedb638ea1f9.Refer to the Image Factory documentation for more information. Download the image and decompress it:

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Writing the Image

Now dd the image to your SD card: 
sudo dd if=metal-arm64.raw of=/dev/mmcblk0 conv=fsync bs=4M

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Bootstrapping the Node

Insert the SD card to your board, turn it on and wait for the console to show you the instructions for bootstrapping the node. Following the instructions in the console output to connect to the interactive installer:
Note: Add the vc4 System Extension for V3D/VC4 Broadcom VideoCore GPU support. 
talosctl apply-config --insecure --mode=interactive --nodes <node IP or DNS name>
Once the interactive installation is applied, the cluster will form and you can then use kubectl.
Note: if you have an HDMI display attached and it shows only a rainbow splash, please use the other HDMI port, the one closest to the power/USB-C port.

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Retrieve the kubeconfig

Retrieve the admin kubeconfig by running: 
talosctl kubeconfig

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Upgrading

For example, to upgrade to the latest version of Talos, you can run:

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Example: Raspberry Pi generic with Broadcom VideoCore GPU support with Image Factory

Let’s assume we want to boot Talos on a Raspberry Pi with the vc4 system extension for V3D/VC4 Broadcom VideoCore GPU support.
Note: The vc4 system extension requires sufficient Contiguous Memory Allocator (CMA) size for GPU operations. See the GPU Memory Issues section for recommended CMA sizes and configuration steps to prevent errors like DRM_IOCTL_MODE_CREATE_DUMB failed.
First, let’s create the schematic file rpi_generic.yaml:

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Schematic example with vc4 system extension

# rpi_generic.yaml
overlay:
  name: rpi_generic
  image: siderolabs/sbc-raspberrypi
  options:
    configTxt: |
      gpu_mem=128
      kernel=u-boot.bin
      arm_64bit=1
      arm_boost=1
      enable_uart=1
      dtoverlay=disable-bt
      dtoverlay=disable-wifi
      avoid_warnings=2
      dtoverlay=vc4-kms-v3d,noaudio
customization:
  systemExtensions:
    officialExtensions:
      - siderolabs/vc4
The schematic doesn’t contain any system extension or overlay versions, Image Factory will pick the correct version matching Talos Linux release.
And now we can upload the schematic to the Image Factory to retrieve its ID: 
$ curl -X POST --data-binary @rpi_generic.yaml https://factory.talos.dev/schematics
{"id":"0db665edfda21c70194e7ca660955425d16cec2aa58ff031e2abf72b7c328585"}
The returned schematic ID 0db665edfda21c70194e7ca660955425d16cec2aa58ff031e2abf72b7c328585 we will use to generate the boot assets.
The schematic ID is based on the schematic contents, so uploading the same schematic will return the same ID.
Now we can download the metal arm64 image:
The Image Factory URL contains both schematic ID and Talos version, and both can be changed to generate different boot assets.
Once installed, the machine can be upgraded to a new version of Talos by referencing new installer image: 
talosctl upgrade --image factory.talos.dev/installer/0db665edfda21c70194e7ca660955425d16cec2aa58ff031e2abf72b7c328585:<new_version>
Same way upgrade process can be used to transition to a new set of system extensions: generate new schematic with the new set of system extensions, and upgrade the machine to the new schematic ID:

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Example: Raspberry Pi generic with Broadcom VideoCore GPU support with Imager

Let’s assume we want to boot Talos on Raspberry Pi with rpi_generic overlay and the vc4 system extension for Broadcom VideoCore GPU support.
Note: The vc4 system extension requires sufficient Contiguous Memory Allocator (CMA) size for GPU operations. See the GPU Memory Issues section for recommended CMA sizes and configuration steps to prevent errors like DRM_IOCTL_MODE_CREATE_DUMB failed.
First, let’s lookup extension images for vc4 in the extensions repository: Next we’ll lookup the overlay image for rpi_generic in the overlays repository: Now we can generate the metal image with the following command: Now the _out/metal-arm64.raw.xz is the compressed disk image which can be written to a boot media. As the next step, we should generate a custom installer image which contains all required system extensions (kernel args can’t be specified with the installer image, but they are set in the machine configuration): The installer container image should be pushed to the container registry: Now we can use the customized installer image to install Talos on Raspberry Pi. When it’s time to upgrade a machine, a new installer image can be generated using the new version of imager, and updating the system extension and overlay images to the matching versions. The custom installer image can now be used to upgrade Talos machine.

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config.txt Information

Refer to the default config.txt file used by the sbc-raspberrypi overlay.

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Configure the config.txt file for usage with the vc4 system extension

Note: Incorrect GPU memory settings in config.txt can lead to rendering failures with the vc4 extension. See the GPU Memory Issues section for guidance on setting the Contiguous Memory Allocator (CMA) size via cma-* parameters. 
...
gpu_mem=128 # <== Add or edit this line
...
hdmi_safe:0=1 # <== Remove this line
hdmi_safe:1=1 # <== Remove this line
...
avoid_warnings=2 # <== Add this line
dtoverlay=vc4-kms-v3d,noaudio # <== Add this line
...

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Troubleshooting

The following table can be used to troubleshoot booting issues:
Long FlashesShort FlashesStatus
03Generic failure to boot
04start*.elf not found
07Kernel image not found
08SDRAM failure
09Insufficient SDRAM
010In HALT state
21Partition not FAT
22Failed to read from partition
23Extended partition not FAT
24File signature/hash mismatch - Pi 4
44Unsupported board type
45Fatal firmware error
46Power failure type A
47Power failure type B

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GPU Memory Issues

The Contiguous Memory Allocator (CMA) reserves physically contiguous memory for Raspberry Pi GPU/display operations (e.g., KMS/DRM rendering). An error like DRM_IOCTL_MODE_CREATE_DUMB failed: Cannot allocate memory indicates an undersized CMA pool for graphics tasks. In Talos Linux, the Raspberry Pi 4’s CMA size is set via bootloader or kernel parameters. The default may be too small for GPU-intensive tasks, and oversizing reduces system memory. CMA Size Guide:
CMA SizeSuitable For
64 MBHeadless, no GPU use
128 MBLight use
256 MBHD media, cameras
512 MB4K media, ML with GPU
1024 MBExperimental, may destabilize

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Change CMA Size

Kernel Parameters: Set CMA size with the cma parameter (e.g., cma=256M, cma=384M). Locate and apply the machine.kernel section to the machine config: 
machine:
  kernel:
    extraArgs:
      - cma=256M
Bootloader via Talos Image Factory:
Talos’s immutable image requires config.txt changes via Talos Image Factory, direct /boot/config.txt edits are lost on upgrades.
In Image Factory, Set CMA size with the cma-* parameter in ConfigTxt (e.g., cma-128, cma-256): 
...
overlay:
  ...
  options:
    configTxt: |-
      ...
      dtoverlay=vc4-kms-v3d,cma-256
      ...