Flashing firmware

The Development Kit has two bootable storage devices: a 64 MB NOR flash and a 32 GB eMMC. A DIP switch on the PCB selects which one the CPU boots from.

All devices ship with NOR pre-flashed. Since the firmware is under active development, you can flash newer versions as they become available — but this is entirely optional.

Overview

The built-in firmware tool auto-detects which medium the device booted from and always flashes the other one. This ensures you never overwrite the firmware you are currently running from.

The recommended procedure is:

1. Boot into recovery from NOR, run firmware update (flashes eMMC)
2. Switch DIP to eMMC, verify it boots
3. Boot into recovery from eMMC, run firmware update (flashes NOR)
4. Switch DIP back to NOR

This order ensures you always have a working recovery environment to fall back on.

Prerequisites

• UART serial console connected (see Getting started)
• An Ethernet cable connected to one of the ports with access to the internet

NOR Flash Memory Map

The 32MB NOR flash image layout (NOR flash itself is 64MB):

Step 1: Back up U-Boot environment variables

Flashing firmware resets U-Boot environment variables back to factory defaults. If you have customized any variables (e.g. a custom boot slot or console setting), save them before proceeding.

Interrupt the U-Boot countdown and run:

=> pri

Copy and paste the entire output somewhere safe. After flashing, you can restore any custom variables with setenv and saveenv.

Step 2: Boot into recovery Linux from NOR

Ensure the DIP switch is set to NOR (this is the factory default). From the U-Boot shell, run:

=> run recovery

Log in as root (no password required).

Step 3: Set up networking

Recovery Linux supports SLAAC, but has no DHCP client. For IPv6 with SLAAC, you only need to enable an interface (ip link set ethX up). For IPv4, you need to configure the network manually. Pick the interface that matches the port you connected your cable to:

For example, if using the third RJ-45 port (eth0) with IPv4:

$ ip link set eth0 up
$ ip addr add 10.0.0.69/24 dev eth0
$ ip route add default via 10.0.0.1 dev eth0

Adjust the interface, IP address, and gateway to match your setup.

Step 4: Flash eMMC

Run the firmware update tool:

$ firmware update

The tool will download the eMMC firmware, verify its signature, and flash it. Follow the on-screen prompts.

Step 5: Switch to eMMC and verify

Flip the DIP switch to eMMC. You can do this while the system is still running — no need to power off. Then reboot:

$ reboot

Watch the serial console output. Confirm you see the following line, which indicates a successful eMMC boot:

INFO:    RCW BOOT SRC is SD/EMMC

Step 6: Boot into recovery Linux from eMMC

Now that eMMC is verified, interrupt the U-Boot countdown again and enter recovery:

=> run recovery

This time, recovery Linux is loaded from eMMC. Log in as root and set up networking the same way as in Step 3:

$ ip link set <interface> up
$ ip addr add 10.0.0.69/24 dev <interface>
$ ip route add default via 10.0.0.1 dev <interface>

Step 7: Flash NOR

Run the firmware update tool again:

$ firmware update

Since you are now booted from eMMC, the tool will automatically target NOR.

Step 8: Switch back to NOR and reboot

Flip the DIP switch back to NOR, then reboot:

$ reboot

Both storage devices are now running the latest firmware. If you backed up custom U-Boot environment variables in Step 1, restore them now using setenv and saveenv.

Manual flashing (legacy)

If your device has an older firmware without the firmware command, you can download and flash manually. Replace <mac-address-with-colons> with your device’s MAC address in lowercase format (e.g. 4d:4f:4e:4f:4d:4f). Run ip a to find it.

The -k flag skips certificate verification, so the download works even when the recovery system’s clock is unset (otherwise curl rejects the not-yet-valid certificate).

Boot from NOR (dip switch set to NOR) to flash eMMC:

$ curl -ku mono:<mac-address-with-colons> -O https://firmware.mono.si/firmware-emmc-gateway-dk.bin
$ dd if=firmware-emmc-gateway-dk.bin of=/dev/mmcblk0 bs=4096 skip=1 seek=1

Boot from eMMC (dip switch set to eMMC) to flash NOR:

$ curl -ku mono:<mac-address-with-colons> -O https://firmware.mono.si/firmware-qspi-gateway-dk.bin
$ flashcp -v firmware-qspi-gateway-dk.bin /dev/mtd0

Note for custom OS images

If you are building your own operating system images for the eMMC, make sure your partitions start at an offset of 32 MB or greater from the beginning of the device. The first 32 MB of the eMMC is reserved for the firmware (bootloader, U-Boot, and recovery Linux). Keeping your OS partitions beyond this boundary ensures you can always re-flash the firmware without overwriting your operating system data.