I created this post as aim to collaborate with the project and help those how are bought a Gigaset GS290 to test this great /e/ OS degoogle fork, and have been failed by using easy installer, but first I will let clearly that these steps are the steps I followed in order to set up the /e/ OS in my Gigaset.

Requirement-system:

  • GNU/Linux OS (in my case Fedora).**
  • ADB & Fastboot library latest.**
  • /e/OS build**
  • boot.img**
  • recovery.img**
  • Basic knowledge in terminal & command line.
  • Sudo

Requirement-smartphone:

  • Android 10 already running in Gigaset Gs290.**
  • USB wire.
  • Developer option enabled.
  • File transfer set as default USB behavior.
  • OEM unlocked.

Before to start please be sure you have the requirement named above!!

  1. Download SDK platform tool from the official site, in my case I downloaded the platform-tools_r31.0.1-linux.zip from the official documentation, they suggested to use the latest version. Unzip its content and into the unziped folder we are gonna to copy and paste the other files.

On this step we have our platform-tools folder.

$ unzip -d . platform-tools_r31.0.1-linux.zip*

  1. Download /e/os build from here it is the same link than the official site in my case I downloaded IMG-e-0.15-q-20210311105636-dev-GS290.zip

  2. Unzip the content, go into the folder unziped IMG-e-0.15-q-20210311105636-dev-GS290 copy the file system.img and paste it into platform-tools below commands:

$ wget https://images.ecloud.global/dev/GS290/IMG-e-0.15-q-20210311105636-dev-GS290.zip
$ unzip -d . IMG-e-0.15-q-20210311105636-dev-GS290.zip
$ mv system.img platform-tools
  1. download recovery.img and boot.img and paste them into platform-tools folder.

I assumed we’re issue the commands into platform-tools

$ wget https://images.ecloud.global/dev/GS290/recovery-e-0.14-q-2021012698290-dev-GS290.img
$ wget https://images.ecloud.global/dev/GS290/boot.img
  1. I assumed you have these requirements already done:
  • Developer option enabled.**
  • File transfer set as default USB behavior.**
  • OEM unlocked.**

If you do not know how to do it, please before to start follow these official instructions(https://doc.e.foundation/pages/enable-usb-debugging)

So connected the smartphone in your pc, and follow step by step the following commands:

sudo ./fastboot reboot
sudo ./fastboot flashing unlock
sudo ./fastboot flash --disable-verity --disable-verification boot boot_g.img
sudo ./fastboot flash recovery recovery_g.img
sudo ./fastboot flash system system_g.img
sudo ./fastboot -w
sudo ./fastboot reboot

On this step your phone is should be restarted and booting in /e/ OS system! congrat !

Further info from official documentation and from the community page here is a really good post

Hope it can be useful.