Install Linux on your F50 or U30 Air

Back up what cannot be replaced

Recommended. This copies your unit's own data (prodnv, the modem calibration and IMEI partitions, the bootloader chain) to your computer and checks every copy against the device.

tools/backup-device.sh          # macOS / Linux, device in rooted Android

Installing never touches these partitions, but if they are ever lost, no firmware download can bring them back and the modem stays broken. Keep the folder somewhere safe and out of any repository: it contains your IMEI. The script runs on macOS and Linux.

Check your device

This only reads; it writes nothing.

./install.sh --check          # macOS / Linux
.\install.ps1 -Check          # Windows (PowerShell)
install.cmd -Check            # Windows (cmd)

It prints the storage size, where Android's partitions end and how much free space follows them. The last line starting with result: is what matters:

No free space at all: the 32 GB variant

If the check finds no room, you have the 32 GB variant, where Android's userdata fills the whole disk. You have two ways:

If the numbers look like neither case, stop and open an issue with what --check printed: they identify the variant.

About the SD card (F50 only)

• A card of at least 700 MiB. It is formatted as ext4 with the label mu300sd. A card that already holds another Linux (ext4) filesystem is never formatted.
• Insert it while the device is off. A card inserted while Linux runs can only be read after the next restart.
• A mu300sd card always starts first. Without the card the device starts the internal installation if there is one. With none, it waits a few seconds for a card, then returns to Android after about five minutes.
• All three kernels read the card. The U30 Air has no slot.
• The device starts any card labelled mu300sd, so whoever has the device can also start their own system from a card.

Install

./install.sh                  # macOS / Linux
.\install.ps1                 # Windows (PowerShell)
install.cmd                   # Windows (cmd)

First it asks for the language, brings your copy of the project up to date with GitHub (and restarts itself if there was anything new), and checks the device again. Then come the questions below. After them it:

1. downloads the ready-made images of the newest release and checks their checksums,
2. copies the Wi-Fi and modem files from your own device (the downloads contain no proprietary files),
3. shows exactly what it is about to write and waits for you to type INSTALL,
4. copies the systems to the device, writes the Linux boot image and arms the Linux slot,
5. adds a small Magisk module to Android, so you can start Linux from Android later without a computer,
6. restarts the device into Linux.

Log in

Wait about a minute after the restart. The device appears on your computer as a new network adapter over USB. Then, in a terminal (on Windows, PowerShell has ssh built in):

ssh ubuntu@192.168.77.1        # Ubuntu on the F50
ssh root@192.168.77.1          # OpenWrt on the F50
ssh ubuntu@192.168.78.1        # Ubuntu on the U30 Air

Use the password you chose during the install. The first time, ssh asks whether you trust the device's key: answer yes.

The two addresses differ so that an F50 and a U30 Air can be plugged into one computer at the same time.

The Wi-Fi network the device broadcasts is its hotspot: unless you chose otherwise, it has the name and password copied from Android.

When the network does not come up at all, there is also a serial console over the same cable, which works even without networking:

screen /dev/cu.usbmodem* 115200   # macOS