Unitree Go2 Expansion Dock Upgrade: Orin Nano 8G → Orin NX 16G

Two Expansion Dock Variants

The Unitree Go2 Expansion Dock comes in two configurations, each equipped with a different NVIDIA Jetson Orin module:

	Jetson Orin Nano 8GB	Jetson Orin NX 16GB
AI Compute	40 TOPS	100 TOPS
Memory	8 GB	16 GB
CPU	6-core Arm Cortex-A78AE	8-core Arm Cortex-A78AE
Max TDP	15W	25W

The NX 16G delivers 2.5× more AI inference performance than the Nano 8G, making it better suited for running more complex perception or control models on the robot. This guide documents the complete procedure for replacing the Nano 8G module with the NX 16G.

It is worth noting that on the Unitree official store, the 100 TOPS expansion dock costs $1,574** more than the 40 TOPS version, while a complete Jetson Orin NX 16G kit can be purchased separately for around **$ 954. Buying the 40 TOPS version and upgrading it yourself is therefore a significantly more cost-effective option.

Since a significant amount of development work had already been done on the Nano 8G (environment setup, dependencies, custom code, etc.), reinstalling everything from scratch on the NX 16G was not desirable. The core approach of this guide is therefore: keep the original Nano 8G SSD and OS intact, and only downgrade the NX 16G's QSPI firmware and update a few config files so that the existing system can drive the NX 16G hardware correctly.

Why You Cannot Simply Swap the Module

A brand-new Jetson Orin NX 16G module ships with JetPack 6.2 (NVIDIA Jetson Linux 36.4.3), while the Unitree factory Expansion Dock runs JetPack 5.1.1 (NVIDIA Jetson Linux 35.3.1).

	JetPack Version	Jetson Linux Version
Unitree factory SSD	JetPack 5.1.1	35.3.1
New NX 16G module	JetPack 6.2	36.4.3

Upgrading from JetPack 5.x to JetPack 6.x is a major version jump, with low-level changes spanning the kernel, driver stack, and BSP structure. More critically, the Jetson module contains a dedicated QSPI-NOR Flash, which stores QSPI firmware (also known as Bootloader / MB2 / CBoot components) that must match the version of Jetson Linux being run.

NVIDIA's official documentation explicitly states that the QSPI firmware for Jetson Linux 35.x (JetPack 5.x) and Jetson Linux 36.x (JetPack 6.x) are incompatible with each other. If the QSPI firmware version does not match the OS version on the SSD, the Jetson will fail to boot — the boot chain cannot complete its handshake, resulting in a boot loop with no way to enter the system.

Reference: Flashing Support — NVIDIA Jetson Linux 36.4.4 Developer Guide (section: Updating Jetson Orin Nano Devkit from JetPack 5 to JetPack 6)

Official quote: "The halt is because of a mismatch between the bootloader in the QSPI and the file system in the SD card. The bootloader version is JetPack 6, and the file system is JetPack 5. JetPack 6 bootloader does not support the JetPack 5 file system."

Why Downgrade Instead of Upgrade?

Since version incompatibility is the core problem, a natural question is: why not go the other direction — upgrade the SSD's OS to JetPack 6.x so it matches the NX 16G module's factory QSPI firmware?

In theory, the NX 16G paired with JetPack 6.2 can unlock MAXN SUPER mode with up to 157 TOPS of AI compute; even the Nano 8G reaches 67 TOPS after upgrading to JetPack 6.2. However, this is not viable on the Go2: the Go2's thermal design and power delivery are built around the power envelope of JetPack 5.1.1. Running at higher performance modes causes severe overheating and current overload, with real risk of hardware damage.

Furthermore, Unitree only provides factory system images for the Go2 based on JetPack 5.1.1 — there is no official JetPack 6.x image for this platform.

The correct approach is therefore to downgrade the NX 16G module's QSPI firmware to match JetPack 5.1.1, rather than upgrading the OS.

Solution

Step 1: Downgrade the QSPI Firmware on the NX 16G Module

Before inserting the NX 16G module into the Unitree Expansion Dock, you must first downgrade its QSPI firmware.

Required Hardware

A Jetson Carrier Board (to put the NX 16G into Force Recovery flashing mode)
A USB Type-C or Micro-USB cable (depending on the carrier board model)
A Linux host machine running Ubuntu

Steps to Flash the QSPI Firmware

Install the NX 16G module onto the Jetson Carrier Board (do not insert the Unitree SSD at this point)
Follow the carrier board instructions to enter Force Recovery Mode (typically by holding the Recovery button while powering on)
Download the NVIDIA Jetson Linux 35.3.1 Driver Package (BSP) on the Linux host
Flash only the QSPI — do not flash the rootfs, so there is no need to download the Sample Root Filesystem

For the exact QSPI-only flash command, refer to the following guide (it uses a JetPack 6 downgrade as the example, but the approach is identical — just substitute the corresponding BSP version):

Reference: GR00T JetPack Flashing Guide

Consult your carrier board's documentation to confirm the exact method for entering Recovery Mode and the correct cable connections.

Once the QSPI firmware downgrade is complete, insert the NX 16G module into the Unitree Expansion Dock and connect the original M.2 SSD — the system will boot successfully at this point. You will be able to see 16 GB of memory and 8 CPU cores, but the module identification and power management modes will still reflect the Nano 8G configuration.

Step 2: Set Up the NX 16G Linux Environment

Once the QSPI firmware downgrade is complete, choose one of the following two options depending on whether you need to preserve your existing development environment:

Option A: Keep the Existing System, Update Config Files

Insert the NX 16G module into the Unitree Expansion Dock and boot from the original SSD. The system will come up, but the kernel will still be loading Nano 8G hardware descriptors and power management will be constrained to the Nano 8G profile. Three files need to be replaced so the system correctly identifies the NX 16G hardware.

Source of replacement files: Mount the NX 16G's Unitree factory image SSD on the current system (e.g. at /media/unitree/7073f027-1f76-471e-8386-b7ac9f58e0e6/) and copy the files directly from it.

1. Replace the Power Management Config `nvpmodel.conf`

Field	Detail
Source	`/media/unitree/7073f027-.../etc/nvpmodel.conf` (NX 16G factory SSD)
Target	`/etc/nvpmodel.conf` (current running system)
Backup	Back up the original as `/etc/nvpmodel.conf.nano8g.bak`
Before	Only two power modes: 15W / 7W
After	Four power modes available: MAXN / 10W / 15W / 25W

sudo cp /etc/nvpmodel.conf /etc/nvpmodel.conf.nano8g.bak
sudo cp /media/unitree/7073f027-.../etc/nvpmodel.conf /etc/nvpmodel.conf

2. Replace the Device Tree Blob (DTB)

The kernel uses the DTB (Device Tree Blob) to identify hardware. The Nano 8G and NX 16G use different DTB files; copy the correct file from the NX 16G factory SSD to overwrite the one in the current system.

Field	Detail
Source	`/media/unitree/7073f027-.../boot/dtb/kernel_tegra234-p3767-0000-p3768-0000-a0.dtb` (NX 16G factory SSD)
Target	`/boot/dtb/kernel_tegra234-p3767-0000-p3768-0000-a0.dtb` (current system)

sudo cp /media/unitree/7073f027-.../boot/dtb/kernel_tegra234-p3767-0000-p3768-0000-a0.dtb \
    /boot/dtb/kernel_tegra234-p3767-0000-p3768-0000-a0.dtb

3. Update the Boot Config `extlinux.conf`

The FDT line in /boot/extlinux/extlinux.conf tells the kernel which DTB to load at boot. The Nano 8G and NX 16G DTB filenames differ by only one number segment:

Field	Detail
File	`/boot/extlinux/extlinux.conf`
Backup	Back up as `/boot/extlinux/extlinux.conf.nano8g.bak`
Before	`FDT /boot/dtb/kernel_tegra234-p3767-0003-p3768-0000-a0.dtb` (Nano 8G)
After	`FDT /boot/dtb/kernel_tegra234-p3767-0000-p3768-0000-a0.dtb` (NX 16G)

sudo cp /boot/extlinux/extlinux.conf /boot/extlinux/extlinux.conf.nano8g.bak
sudo sed -i 's/p3767-0003-p3768/p3767-0000-p3768/g' /boot/extlinux/extlinux.conf

After editing, verify that the FDT line in the file points to the p3767-0000 DTB.

After completing all three steps, reboot:

sudo reboot

After rebooting, the kernel will load the NX 16G hardware descriptors. The system platform will correctly identify as Orin NX, power management will unlock the 25W and MaxN modes, and any EMC (memory controller) related errors will be gone.

Verify with the following commands:

# Check module model
cat /proc/device-tree/model

# Check available power modes
sudo nvpmodel -q

Option B: Clean Install with the Unitree Official NX Image

If there is no need to preserve an existing development environment and you just want a clean factory system, you can use an M.2 reader to write the Unitree official NX 16G image directly to the M.2 SSD, skipping the config file edits above.

Required Materials

An M.2 NVMe reader (USB to M.2 adapter)
A Linux machine
The Unitree official NX 16G system image: go2_nx_Jetpack5.1.1_20250930.img.bz2, download link available from the Unitree Module Upgrade Documentation (Google Drive)

Steps

Extract the image:

bzip2 -d go2_nx_Jetpack5.1.1_20250930.img.bz2

Connect the SSD via the M.2 reader and confirm the device path:

lsblk

Write the image (replace /dev/nvmeXn1 with the actual path — verify the device path before running):

sudo dd if=go2_nx_Jetpack5.1.1_20250930.img \
    of=/dev/nvmeXn1 \
    bs=64M \
    status=progress \
    oflag=direct

Once the write is complete, install the SSD back into the Expansion Dock and insert the NX 16G module (with QSPI firmware already downgraded) — it will boot directly

Two Expansion Dock Variants​

Why You Cannot Simply Swap the Module​

Why Downgrade Instead of Upgrade?​

Solution​

Step 1: Downgrade the QSPI Firmware on the NX 16G Module​

Required Hardware​

Steps to Flash the QSPI Firmware​

Step 2: Set Up the NX 16G Linux Environment​

Option A: Keep the Existing System, Update Config Files​

1. Replace the Power Management Config nvpmodel.conf​

2. Replace the Device Tree Blob (DTB)​

3. Update the Boot Config extlinux.conf​

Option B: Clean Install with the Unitree Official NX Image​

Required Materials​

Steps​

References​