Merge branch '159-improve-FP3-installation' into 'master'

## Installing /e/OS from the bootloader

{% include alerts/tip.html content="Some of the commands have a -S after them. Please note it is a hyphen '-' followed by a capital 'S' and the value 522239K "%}

{% include alerts/tip.html content="For Windows users, we advise to use Git Bash. For more info about Downloads and Installation see https://git-scm.com/about"%}

1. Unzip the archive

    unzip fileyoudownloaded

    ```

   > Replace `fileyoudownloaded` with the name of the archive file you downloaded . You can unzip the files into the folder where you copied the fastboot files.

   > Replace `fileyoudownloaded` with the name of the archive file you downloaded.

   > Alternately you can create a folder and unzip the archive there.

   >  In the second case the below commands will need the path to the folder where you unzipped the archive.

1. Install /e/OS using the following commands (from fastboot mode)

    ```

    fastboot -w

    fastboot flash system_a system.img -S 522239K

    fastboot flash boot_a boot.img

    fastboot flash vendor_a vendor.img -S 522239K

    fastboot flash dtbo_a dtbo.img

    fastboot flash vbmeta_a vbmeta.img

    fastboot flash system_b system.img -S 522239K

    fastboot flash boot_b boot.img

    fastboot flash vendor_b vendor.img -S 522239K

    fastboot flash dtbo_b dtbo.img

    fastboot flash vbmeta_b vbmeta.img

    fastboot flashing lock

    ```

    - The last command will ask you to confirm on the device to lock the bootloader.

1. Confirm that extracted directory contains following content:

    - `bin-linux-x86 directory` - which contains linux tools including fastboot and adb

    - `bin-msys directory` - which contains Windows tools including fastboot and adb

    - `img files` - The `img` files that are to be flashed onto the device.

    - `flash_FP3_factory.sh` - The installer script.

    - Select **LOCK THE BOOTLOADER** with `Volume +` and valid with `Power`.

1. Boot into bootloader/fastboot mode.

    - Power OFF the device and press `Volume Down + Power` buttons simultaneously.

    - On previous version of `fastboot`, the last command is `fastboot oem lock`

1. Enjoy! The device will now reboot automatically on /e/OS.

1. Run the installer script on terminal(Linux) or on Git Bash UI(Windows).

### Getting a `fastboot` error ?

1. Make sure you are in the current directory which contains the `flash_FP3_factory.sh` file.

-  On some versions of `fastboot` you may get an error while running the `Fastboot flash boot boot.img` command

    Linux

    - Right click -> Open terminal here

    Windows

    - Right click -> Git Bash here

- The below error may show up on the console

    - Execute the following command:

    ```

    fastboot error: couldn’t parse partition size ‘0x’

    chmod +x flash_FP3_factory.sh && ./flash_FP3_factory.sh

    ```

- A workaround for this error is as under. Run this command on the console:

    - The script will flash all required files and will wait for input at the last step.

    ```

    fastboot getvar current-slot

    ```

- This would show the current active slot. For e.g. if it shows `a` , run the below command

    - The last command will ask you to confirm on the device to lock the bootloader.

    ```

    fastboot --set-active=b

    fastboot flash boot_b boot.img

    ```

{% include alerts/tip.html content= "If you find an issue with this installation document or if you want to suggest improvements, Please create a dedicated thread on our  [community forum](https://community.e.foundation/) "%}

    - Select **LOCK THE BOOTLOADER** with `Volume +` and validate with `Power` button.

1. Enjoy! The device will now reboot automatically on /e/OS.

{% include alerts/tip.html content= "If you find an issue with this installation document or if you want to suggest improvements, Please share your suggestion in [this document](https://community.e.foundation/t/fairphone-fp3-fp3-documentation-suggestions/20955) "%}

{% include alerts/success.html content= "Congratulations !! Your phone should now be booting into /e/OS !! "%}