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Documentation Index

Fetch the complete documentation index at: https://mintlify.com/gueritta/primemixxx/llms.txt

Use this file to discover all available pages before exploring further.

The Denon Prime Go ships with a locked-down Engine OS that does not include SSH access. To develop or debug primemixxx on-device you need to flash the stock-with-SSH firmware variant, which is a stock Engine OS image with an SSH key pre-installed and the USB Ethernet gadget enabled. A fully custom MIXXX firmware image also exists but currently has a known SSH-disabled blocker — see the warning below.
After flashing the custom MIXXX firmware (PRIMEGO-4.3.4-MIXXX-SSH-Update.img), port 22 is refused — sshd.service is not enabled in the Buildroot defconfig. You cannot SSH into the device until you restore the stock-with-SSH firmware. Always use PRIMEGO-4.3.4-STOCK-SSH-Update.img for day-to-day development.

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Available Firmware Images

FileDescription
PRIMEGO-4.3.4-STOCK-SSH-Update.img✅ Recommended — stock Engine OS + SSH key + USB Ethernet gadget
PRIMEGO-4.3.4-MIXXX-SSH-Update.img⚠️ Custom MIXXX firmware — SSH currently broken after flash
PRIMEGO-4.3.4-Update.imgStock firmware, no SSH access
PRIMEGO-2.3.2-Update.img – PRIMEGO-4.3.3-Update.imgHistorical stock versions (2.3.2–4.3.3)
PRIME4-2.2.1-Update.img – PRIME4-4.3.4-Update.imgPrime 4 stock versions (2.2.1–4.3.4)
.img files are symlinks to their corresponding .img.dtb Device Tree Blob packages.

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Rebuilding the Stock-SSH Firmware

To rebuild PRIMEGO-4.3.4-STOCK-SSH-Update.img from its source DTS and rootfs: 
# Source DTS: PRIMEGO-4.3.4-STOCK-SSH-Update.img.dts
# Rootfs:     unpacked-ssh-img/rootfs-stock-ssh.img.xz
make PRIMEGO-4.3.4-STOCK-SSH-Update.img.dtb
The .dtb file is the firmware package consumed by fastboot and the Go updater. The .img symlink points to it.
Use go run ./cmd/find_update/ from the go/ directory to identify and locate firmware update files in the repository.

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Flashing Methods

2
The cross-platform Go-based updater uses libusb and the FastBoot protocol directly. The firmware image path is configured in config.toml via the ImagePath field of each device entry.
3
# 1. Put the device in update (loader) mode via SSH
ssh root@primego.local reboot loader

# 2. Run the updater from the go/ directory
cd go && go run ./cmd/updater/
4
The updater will detect the device via USB, verify the firmware SHA1 checksum, decompress the rootfs on-the-fly, and flash each partition. A GUI progress window is displayed during flashing.
5
Method 2: USB Drive Flash
6
Use this method if fastboot reports “too large for partition” (see Known Issues below).
7
  • Format a USB drive as FAT32
  • Copy the .img file to the root of the USB drive
  • Insert the USB drive into the Prime Go
  • Power the device into update mode (hold the power button and select Update, or use the hardware recovery sequence)
  • The device will detect the firmware file and flash automatically
    • 8
    Method 3: SSH + fastboot (Requires SSH Already Enabled)
    9
    Only usable if you already have SSH access:
    10
    # Put device in loader/fastboot mode
ssh root@primego.local reboot loader

# Flash using system fastboot CLI
fastboot flash system ../PRIMEGO-4.3.4-STOCK-SSH-Update.img

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    Go Updater CLI Reference

    The Go updater (go/cmd/updater/) implements FastBoot over libusb with a GUI progress display. The firmware image path is set in config.toml — there is no --firmware command-line flag.
    FlagDefaultDescription
    --debug <level>8Logging level: -4 = debug, 0 = info, 4 = warn, 8 = error only
    --logfile <path>(empty)Write logs to file (disabled if empty)
    --libusb_debug <level>0libusb debug verbosity (0–3)
    --skip_rebootfalseSkip automatic device reboot after flashing
    --dryfalseDry run — device must be connected but will not be flashed
    # Example: run with verbose debug logging to file
cd go && go run ./cmd/updater/ \
  --debug -4 \
  --logfile /tmp/updater.log
    The updater reads device IDs, firmware version, and partition layout from the Device Tree Blob embedded in the .img file. SHA1 checksum verification is performed before flashing begins.
    The Go updater takes roughly twice as long as the system fastboot CLI due to buffer size differences in the FastBoot implementation (~30s for fastboot, ~60s for the Go tool). This is a known limitation — see go/doc/updater.md for details.

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    Known Issues

    “Too large for partition” via fastboot — rootfs-stock-ssh.img.xz unpacks to ~512 MB and may exceed the Prime Go’s rootfs partition size when flashed via fastboot. The stock rootfs fits exactly; the SSH additions push it just over the limit.Workaround: Use the USB drive flashing method (Method 2 above) instead of the Go updater or fastboot CLI. The device’s update mode reads directly from USB mass storage and handles the partition layout differently.

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