Developer Mode Enables All TTY Lines For Docker-Contained Debian

Instead of dual-booting the Chromebook, the developer mode is enough to allow Gentoo-based Linux to install socat.

Use ESC-Refresh(F2)-Power, then Ctrl-D to set up developer mode of the Chromebook, as so,

Then use Ctrl-Alt-F4 to enter the root account of Gentoo and install development tools with dev_install, as so,

Socat is verified as part of the development tool as the following screenshot.

When installing the Gentoo developer environment, use the highest direct root account login privilege, not the sudo temporary privilege. As the screenshots below show, an access problem occurs within a minute of using sudo privilege.

Either of the 2 options with the problematic sudo command results in no socat installation, and the message after you make a choice, humorously, hints that you will not enjoy the outcome, saying "enjoy it, or not."

TODO: Connect Chromebook Gentoo base Linux's /dev/ttyACM0 to a Crostini Linux docker container running Debian using socat on IP address 100.115.92.1, so that the BLHeli configurator can connect to the pass-through ESCs.

UDP Forwarding Needs Socat

UDP port forwarding with Chromebook's Gentoo base Linux kernel-space iptables does not work.

Instead, disregard the GUI Port Forwarding, and use the base root account to open the firewall port, as so,

sudo iptables -I INPUT -p udp --dport [target port] -j ACCEPT

, and then execute socat as so,

socat UDP4-RECVFROM:[listen port],fork UDP4-SENDTO:[target IP]:[target port]

. Example of forwarding RTP UDP video stream is here.

As of today, most Chromebooks can run the Intel EDKII program that loads Linux operating systems. The ed2 program is developed by MrChromebox.tech. And that website has the procedure and command line to install the edk2 program. The edk2 program is called an "alternative boot loader" in the Chromebook ecosystem.

After you have enabled developer mode, installed edk2, and rebooted the Chromebook, you will see the first program of the ChromeOS suite on the screen, similar to the following.

After you select to run the edk2 program, it searches for a non-ChromeOS disk partition with a rabbit splash picture. And until you actually install a non-ChromeOS Linux distribution, or insert a live Linux USB disk, which is also a Linux installation program, the edk2 program will fail and force a reboot.

If and when you are stuck with a "bricked" Chromebook after installing the ed2 program, simply power off and press ESC-Refresh(F2)-Power to rescue it via internet recovery.

ChromeOS will erase all user data and then repopulate data of your Google account into ChromeOS.

Then, all you need is running the CRAP partition resizing script in [Ctrl-Alt->F2] terminal with root account (no password after booting ChromeOS after enabling developer mode) to make room for a Linux distribution. To enter [Ctrl-Alt->F2] terminal, press simultaneously the Ctrl, Alt, and the refresh (F2) keys. The script is at https://tinyurl.com/crap-cb-01 . The script is developed by Chrultrabook.com . To run the script without saving it, do this,

# bash <(curl -L https://tinyurl.com/crap-cb-01)

To prepare the live Linux USB disk, you need the Crostini Linux container (virtual machine) Linux development environment set up in your Chromebook. This is achieved by searching for "developer" in the settings (gear icon) window, as so,

Xubuntu is the most recognized, smallest useful operating system. The Xubuntu disk image was downloaded from xubuntu.org and "burned" onto the disk via the Crostini ChromeOS container shell terminal. ChromeOS allows you to give full control of the /dev/sda device to the Crostini container when you open the USB settings (gear icon again) window and search for "USB." You need to eject the flash USB disk in ChromeOS for Crostini to take control (and "burn" the disk) of it.

The disk "burning" program in the Crostini terminal is called dd, developed by the GNU.org. The command line to "burn" the disk image was so,

# dd if=/mnt/chromeos/removable/XXXY-ZZZZ/xubuntu-24.04.3-minimal-amd64.iso of=/dev/sda

. It took about 25 minutes to burn the 2.6 GB image at a speed of 1.7 MB/s.

In the following example, I split ChromeOS's user home partition in half, giving Xubuntu 24.04.3 60 GB of space.

The picture here shows that only 1 flash USB drive is needed to host the Xubuntu live disk image throughout the entire project of enabling dual booting.

The installation process was completed using a cellular hotspot or a coffee shop's Wi-Fi to download 900 MB of hotfixes for advanced software, such as GPU drivers. The Xubuntu installation live operating system was loaded by the edk2 program. The regular Xubuntu installation program has a desktop shortcut to invoke. The Xubuntu installation took less than 10 minutes using Google Fi cellular hotspot, as shown by the timestamp.

The live Linux does not recognize the MicroSD card, whereas the installed Linux does in the following picture of the rebooted installation, displayed as a 64 GB Volume.