[HOWTO] a Clear Guide to install "IMG-e-builds" when /e/ web installer fails

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in 3 copy / paste actions !

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because even well illustrated, the “web-installer” often don’t work,

and because the official documentation is imbuvable for some new users.

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here we take the Fairphone 6 as example,
but it is the same logical and quite the same process for all the devices that have :

  • only "IMG-e-xxxxxxxxxxx.zip" file on their download page,
  • no "recovery-e-xxxxxxxxxx.img" file on their download page,
  • no "recovery-IMG-e-xxxxxxxxxx.zip" file on their download page,
  • that contains an install script named like flash_FP6_factory.sh.

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(non exhautive device list)
Fairphone : FP3, FP4, FP5, FP6,
Gigaset : GS290,
Murena : one, two,
Nothing : tetris,
OnePlus : avicii,
Google : panther,
Shift : axolotl, otter,
Teracube : sapphire,
Volla : mimir,
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for other devices that have
"recovery-e-xxxxxxxxxx.img" or "recovery-IMG-e-xxxxxxxxxx.zip" file
on their download page, use this : [HOWTO] an Unified Install Guide Project for /e/

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Windows Guide :

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Expand

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according to Install /e/OS on a Fairphone The Fairphone (Gen. 6) - “FP6”

If you plan to relock the bootloader after the installlation

(not mandatoty, only available with Official version, why relocking ?)
Most important thing to take care about is the “android Security Patch Level” in the already installed Operating System on your device before you start the install process.

It must be OLDER than the “android Security Patch Level” included in the /e/OS build you want to install, otherwise you risk to change your device into Brick.

  • You will find this information about stock OS on the device :

settings --> about phone --> android version 15 --> android security update

  • you will find this information about /e/OS build on the install instructions page for you device if your device is supported by /e/

  • but also on the release article about the /e/OS version you want to install even if you device have no instructions page :
    the title of the article need to match both “/e/OS version” and “android level”,
    currently "e-3.2-a15"

Releases · e / os / :rocket: Releases · GitLab


more detailled explications here : (answered) Install /e/ on FP5 with newer Security Patches

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other things you must take care about

Your Stock OS Android version, must be the latest available relative to the /e/OS build you want to install → not higher !

Remove all Gogol accounts, screen lock or SIM lock from the device.

Use a USB-A to USB-C cable on a rear USB port (no hub even internal if possible)

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Unlocking the bootloader

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the “Unlocking the bootloader” step may differ, so to be safe, allways have a read on

Smartphone Selector” → “Official or Community install doc” for your device → “Command line” install page for your device !

in case of Fairphone devices, get the Unlock code from Fairphone before proceeding with the next steps

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on your device, enable USB debugging and allow OEM unlocking .

  • Reboot the device to bootloader mode with the command adb reboot bootloader,
    or with the device powered off - hold Volume Down + Power

On your PC, install Git-bash, and confirm all preselected options.

download the “platform-tools for windows”, and just extract the .ZIP, not more.

open the newly created “platform-tools” folder in your file manager, then

  • use the right clic of your mouse, and choose open Git Bash here.

you will get something like :

  • Ask for unlock by copy this command and paste it in the terminal :
.\fastboot flashing unlock
  • Approve with volume + then power

The device proceed with a factory reset, and automatically reboots

Reboot again into bootloader

  • Unlock critical by copy this command and paste it in the terminal :
.\fastboot flashing unlock_critical
  • Approve with volume + then power

The device proceeds with a factory reset, and automatically reboots

the Bootloader is now unlocked

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Installing /e/OS

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Again reboot the device into bootloader mode.

on your PC, take latest /e/OS official FP6 download and just extract it, not more.

From the newly created folder /IMG-e-3.2-a15-20251022539003-official-FP6,

  • right clic with your mouse, and choose open Git Bash here.

  • copy this command and paste it in the git-bash terminal :

chmod +x flash_FP6_factory.sh && ./flash_FP6_factory.sh

you will get something like :

you are done with installing /e/OS

now run :

fastboot reboot

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Finaly,

only if the android security update in the previously installed Stock OS was older
than the android security update included in the /e/ build you want to install
you will be abble to relock the bootloader according to instructions at the bottom of the device install page (only possible with Official version)

with the device in bootloader mode, check bootloader status by running :

fastboot oem device-info
fastboot flashing get_unlock_ability

if the return is 0
DON’T TRY TO RELOCK
risk is to brick your device (wait untill an /e/OS update)

if the return is 1
→ you can relock

fastboot flashing lock_critical
fastboot flashing lock

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What could go wrong

[Solved] Windows does not see my phone in Fastboot mode because needed drivers are not correctly installed

Tip :

if not properly "installed in your path” as explained in Installing adb and fastboot on Windows PC ,
simply add ./ at the beginning of all your adb or fastboot commands,
it will use the version included into the relative folder (the latest) instead of the one installed on your system (that can be outdated)

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Linux Guide :

.

Expand

.

according to Install /e/OS on a Fairphone The Fairphone (Gen. 6) - “FP6”

If you plan to relock the bootloader after the installlation

(not mandatoty, only available with Official version, why relocking ?)
Most important thing to take care about is the “android Security Patch Level” in the already installed Operating System on your device before you start the install process.

It must be OLDER than the “android Security Patch Level” included in the /e/OS build you want to install, otherwise you risk to change your device into Brick.

  • You will find this information about stock OS on the device :

settings --> about phone --> android version 15 --> android security update

  • you will find this information about /e/OS build on the install instructions page for you device if your device is supported by /e/

  • but also on the release article about the /e/OS version you want to install even if you device have no instructions page :
    the title of the article need to match both “/e/OS version” and “android level”,
    currently "e-3.2-a15"

Releases · e / os / :rocket: Releases · GitLab


more detailled explications here : (answered) Install /e/ on FP5 with newer Security Patches

.



.

other things you must take care about

Your Stock OS Android version, must be the latest available relative to the /e/OS build you want to install → not higher !

Remove all Gogol accounts, screen lock or SIM lock from the device.

Use a USB-A to USB-C cable on a rear USB port (no hub even internal if possible)

.




.

Unlocking the bootloader

.

the “Unlocking the bootloader” step may differ, so to be safe, allways have a read on

Smartphone Selector” → “Official or Community install doc” for your device → “Command line” install page for your device !

in case of Fairphone devices, get the Unlock code from Fairphone before proceeding with the next steps

.

on your device, enable USB debugging and allow OEM unlocking .

  • Reboot the device to bootloader mode with the command ./adb reboot bootloader,
    or with the device powered off - hold Volume Down + Power

On your PC, download the “platform-tools for Linux”, and just extract the .ZIP, not more.

open the newly created “platform-tools” folder in your file manager,

  • use the right clic of your mouse, and choose open in a terminal.

you will get something like :

  • Ask for unlock by copy this command and paste it in the terminal :
./fastboot flashing unlock
  • Approve with volume + then power

The device proceed with a factory reset, and automatically reboots

Reboot again into bootloader

  • Unlock critical by copy this command and paste it in the terminal :
./fastboot flashing unlock_critical
  • Approve with volume + then power

The device proceeds with a factory reset, and automatically reboots

the Bootloader is now unlocked

.




.

Installing /e/OS

.

Again reboot the device into bootloader mode.

on your PC, take latest /e/OS official FP6 download and just extract it, not more.

From the newly created folder /IMG-e-3.2-a15-20251022539003-official-FP6,

  • right clic with your mouse, and choose open in a terminal.
  • copy this command and paste it in the terminal :
chmod +x flash_FP6_factory.sh && ./flash_FP6_factory.sh

you will get something like :

you are done with installing /e/OS

now run :

fastboot reboot

.

.




.

Finaly,

only if the android security update in the previously installed Operating System was older
than the android security update included in the /e/OS build you want to install
you will be abble to relock the bootloader according to instructions at the bottom of the device install page (only possible with Official version)

check bootloader status by running :

./fastboot oem device-info
./fastboot flashing get_unlock_ability

if the return is 0
DON’T TRY TO RELOCK
risk is to brick your device (wait untill next /e/OS update)

if the return is 1
→ you can relock

fastboot flashing lock_critical
fastboot flashing lock

.

Tip :

if not properly "installed in your path” as explained in Installing adb and fastboot on Linux PC ,
simply add ./ at the beginning of all your adb or fastboot commands,
it will use the version included into the relative folder (the latest) instead of the one installed on your system (that can be outdated)

.




.

macOS Guide :

.

Expand

.

according to Install /e/OS on a Fairphone The Fairphone (Gen. 6) - “FP6”

If you plan to relock the bootloader after the installlation

(not mandatoty, only available with Official version, why relocking ?)
Most important thing to take care about is the “android Security Patch Level” in the already installed Operating System on your device before you start the install process.

It must be OLDER than the “android Security Patch Level” included in the /e/OS build you want to install, otherwise you risk to change your device into Brick.

  • You will find this information about stock OS on the device :

settings --> about phone --> android version 15 --> android security update

  • you will find this information about /e/OS build on the install instructions page for you device if your device is supported by /e/

  • but also on the release article about the /e/OS version you want to install even if you device have no instructions page :
    the title of the article need to match both “/e/OS version” and “android level”,
    currently "e-3.2-a15"

Releases · e / os / :rocket: Releases · GitLab


more detailled explications here : (answered) Install /e/ on FP5 with newer Security Patches

.



.

other things you must take care about

Your Stock OS Android version, must be the latest available relative to the /e/OS build you want to install → not higher !

Remove all Gogol accounts, screen lock or SIM lock from the device.

Use a USB-A to USB-C cable on a rear USB port (no hub even internal if possible)

.




.

Unlocking the bootloader

.

the “Unlocking the bootloader” step may differ on some devices, so to be safe, allways have a read on

Smartphone Selector” → “Official or Community install doc” for your device → “Command line” install page for your device !

in case of Fairphone devices, get the Unlock code from Fairphone before proceeding with the next steps

.

on your device, enable USB debugging and allow OEM unlocking .

  • Boot the device to bootloader mode with the command ./adb reboot bootloader,
    or with the device powered off - hold Volume Down + Power

on your macOS,
download the latest /e/OS build from Smartphone Selector,
then extract the.ZIP, and rename the newly created folder
“IMG-e-3.2-a15-2025xxxxxxxxxx-xxxxxxxxx-xxxxxxxx” into "IMG-e".

open the macos terminal from “Applications” → utilities → terminal.
you will see something like :

  • Ask for unlock the bootloader by copy this command and paste it in the terminal :
~/Downloads/IMG-e/bin-darwin/./fastboot flashing unlock
  • Approve with volume + then power

The device proceed with a factory reset, and automatically reboots

Reboot again into bootloader

  • Unlock critical partitions by copy this command and paste it in the terminal :
~/Downloads/IMG-e/bin-darwin/./fastboot flashing unlock_critical
  • Approve with volume + then powe r

The device proceeds with a factory reset, and automatically reboots

the Bootloader is now unlocked

.




.

Installing /e/OS

.

Again reboot the device into bootloader mode.

.

On your computer in the terminal,

  • copy this command and paste it in the terminal :
~/Downloads/IMG-e/chmod +x flash_FP6_factory.sh && ./flash_FP6_factory.sh

you will get something like :

you are done with installing /e/OS

now run :

~/Downloads/IMG-e/bin-darwin/./fastboot reboot

.

.




.

Finaly,

only if the android security update in the previously installed Operating System was older
than the android security update included in the /e/OS build you want to install
you will be abble to relock the bootloader according to instructions at the bottom of the device install page (only possible with Official version)

.

Again reboot the device into bootloader mode.

check bootloader status by running :

~/Downloads/IMG-e/bin-darwin/./fastboot oem device-info
~/Downloads/IMG-e/bin-darwin/./fastboot flashing get_unlock_ability

if the return is 0
DON’T TRY TO RELOCK
risk is to brick your device (wait untill next /e/OS update)

if the return is 1
→ you can relock

~/Downloads/IMG-e/bin-darwin/./fastboot flashing lock_critical
~/Downloads/IMG-e/bin-darwin/./fastboot flashing lock

.

Tip :

if not properly "installed in your path” as explained in Installing adb and fastboot on Linux PC ,
simply add ./ at the beginning of all your adb or fastboot commands,
it will use the version included into the relative folder (the latest) instead of the one installed on your system (that can be outdated)

.




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Feel free to ask if you still encountred issue.

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you may also be interrested by :
[HOWTO] Upgrade my /e/OS to major Android version without loosing /data

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3 Likes

Hi

The installation script won’t run for me. It claims I have critical partitions locked which might be true. I’m on LineageOS 23 and Fairphone 4 and already have an unlocked bootloader.

I booted to the bootloader (“adb reboot bootloader”) and ran the script. I tried “fastboot flashing unlock” and “fastboot flashing unlock_critical”.

Do I need to maybe revert back to the FairphoneOS and relock and then unlock the bootloader? Sounds risky…:thinking:

Please check the “android security update” of your LOS 23, it must be older than 2025.10.01

1 Like

Oh okay. I guess I’ll have to wait a while and try again. Thanks!