Saturday, December 12, 2015

Exporting the Firefox OS Offline Calendar (Firefox OS migration part 1)

Update 2016-03-21: Improved visual appearance and simplified steps 5 onwards - conversions can be done in the browser directly now without having to use Python.


This how-to will describe a way to export the calendar entries of your Firefox OS phone and convert the data into a standard iCalendar / ICS file that can be imported into almost any program / phone / online service.

Why is this even necessary? When Mozilla introduced the Firefox OS product line it started with big promises: Just create a HTML5 application, and it will run on every device including Firefox OS. Unfortunately Mozilla forgot a few essential things, for example to include an API to access calendar data. If you have been using the offline calendar (or your CalDAV server went offline) then the calendar ended as a data sink - you can put stuff in, but you won’t get it out any more with conventional means.

When migrating to another phone (or if you want to get a useful backup copy) you may still want to migrate your calendar data. This article will guide you through this (lengthy) process. A second article for the migration of SMS / MMS data is planned.


This how-to was created on Linux with a German ALCATEL ONE TOUCH FIRE, updated to the official Firefox OS version by the provider. Just saying in case something is working differently in your setup - the instructions should be quite generic and platform independent though ;-)

Step 1: Basic setup

First things first: Both your computer and your phone will have to be configured to allow them to communicate with each other. We will configure the phone, install the Android Debug Bridge extension in Firefox and try the first connection to the phone.

  1. On your phone go to SettingsDevice / Device informationMore InformationDeveloper settings / Developer and select Remote debugging.
  2. In Firefox press the Alt key and select ToolsWeb DeveloperWebIDE in the menu.
  3. In the Firefox WebIDE select Select RuntimeUSB DEVICES / Install ADB Helper.
  4. Install the ADB Helper Add-on.
  5. Choose Select Runtime again and click on your device in the USB DEVICES section.
  6. Accept the connection request on your phone.
  7. Back in the Firefox WebIDE select RuntimeRuntime Info.
  8. Check the value of ADB is root.
  9. If it’s no click on root device.
  10. Remember if it says yes or no now (you will need it for Step 3).

If any of these steps didn’t work go to Mozilla’s troubleshooting site - you will most probably find the solution to your problem there.

Step 2: Connecting to the device on the command line

Excellent - the connection to the phone is working; unfortunately Firefox’s WebIDE doesn’t support transferring files or booting a custom kernel, so we will have to use ADB on the command line.

  1. In Firefox enter about:support into the address line.
  2. Select Application Basics / Profile Directory / Open Directory.
  3. In your file manager navigate to
  4. You will find a directory named after your operating system here (e.g. linux, linux64, win32 or mac64).
  5. Open this directory in a console (Linux / Thunar: right-click on the directory and choose Open Terminal Here; Linux / Dolphin: right-click on the directory and choose ActionsOpen Terminal Here; Windows: How to Use “Open Command Window Here” in Windows 7 (inofficial instructions); Mac OS: Open terminal here in Mac OS finder (inofficial instructions)).
  6. Make sure your phone’s display is turned on and the screen is unlocked - otherwise your device won’t be listed in the next step.
  7. Type ./adb -l (on Linux and Mac) or adb -l (on Windows).
  8. You should see the (internal) name of your device now.

Step 3: Getting root access to your device

Check if your phone is locked by the vendor and (temporarily) boot an alternative kernel if it is.

  1. Remember step 1 when we checked if ADB is root said yes or no? If it was yes: everything is fine and you can directly go to step 4.
  2. Otherwise you will have to find a kernel allowing root access for your device. You should be able to find one on - just choose your device and download the appropriate file. Note: We don’t want to flash the whole device, so most of the documentation on the site isn’t necessary.
  3. You will probably have downloaded a ZIP file - in my case I’ve downloaded the “Version 1.4” image, as that version was closest to the one installed on my phone; I’ve also tried a 2.6 image successfully, so you will probably be fine with any version you can get (don’t blame me if anything goes wrong though :-)).
  4. Extract that ZIP file - it should contain a file called boot.img, which is the one we need.
  5. Restart your phone and keep the volume down button pressed. Keep it pressed for five seconds after seeing your device manufacturer’s logo.
  6. If the manufacturer’s logo stays there you have now successfully entered fastboot mode.
  7. On the command line type ./fastboot boot "<path containing the extracted files>/boot.img" (in my case the patch was /tmp/14_20150406/boot.img; leave out the ./ at the beginning of the line on Windows; on Linux you have to be root for this command to work).
  8. Your phone should continue booting as normal.
  9. When the boot has finished and you unlocked the screen try connecting to your phone via Firefox WebIDE again - you should get ADB is root: yes now.

Step 4: Getting the data from the phone

Now that everything is working we will transfer the calendar data from the phone and store it on your PC.

  1. For the sake of convenience we will do a backup of all your data (otherwise we would have to find out the exact file name for your device first); type ./adb pull /data/local/storage on the command line (again without the leading ./ on Windows).
  2. When the transfer is complete a directory called persistent will contain a backup of your data; if you have a very recent version of Firefox OS you may have gotten three directories called default, permanent and temporary instead - this will make a difference in step 5. In any case I’d recommend using your file manager to move those directories out of the Firefox profile now and keep them in a save place ;-)
  3. If you want you can reboot your phone now (and get the original kernel back) - we have all the data we need.

Step 5: Importing the data into Firefox

You just backed up several SQLite files.

In case you are interested some technical background: Firefox OS is using IndexedDB to store it’s data. IndexedDB itself is using an SQL database, however the data is not stored in plain text, but only as an internal serialized representation; this is also the reason why we can only use Firefox to decode the data again: Other browsers have different internal representations and wouldn’t be able to decode it. Fortunately the serializer is the same for desktop Firefox and Firefox OS…

The data will be imported into Firefox now. IndexedDB data is always connected to a specific URL, so we will have to create a fake one.

If your phone’s backup data resides in a directory called persistent proceed with step 5a, if you got default and permanent instead proceed with step 5b.

Step 5a: When you got a “persistent” directory

  1. You got the data in an old format. In the following steps a new profile will be created, as the databases have to be migrated to Firefox’s new internal format first.
  2. Close Firefox.
  3. Start Firefox’s ProfileManager by typing firefox --ProfileManager --new-instance on the command line.
  4. Click Create Profile….
  5. Click Next.
  6. Enter a profile name (e.g. Firefox OS import)
  7. Remember the directory that is shown in the middle of the dialogue and click Finish.
  8. Don’t start Firefox yet!
  9. Open the directory you just created in your file manager - it should be almost empty.
  10. In the profile directory create a new directory called storage.
  11. In the storage directory create another directory called persistent.
  12. Inside persistent create another directory called
  13. Inside that directory create a directory called idb.
  14. Now copy all the calendar data from your phone backup into this directory. You will need the sqlite and sqlite-journal files - on my device they were located in persistent/
  15. Now you can finally start Firefox - but make sure that Use the selected profile without asking at startup is not selected; Firefox will migrate the data to it’s new storage format, so don’t be surprised when the directories you just created don’t exists any more afterwards.

Step 5b: When you got a “default” directory

  1. Switch to your file manager: The default directory of your phone backup data should contain a directory ending with
  2. Copy this directory into the directory storage/default of your Firefox profile.
  3. Now rename the directory to

Step 5: Continued (both cases)

  1. In Firefox open the URL If you just created a new Firefox profile (Step 5a) use the new browser window to open the URL!
  2. Click on Export database and press the Export button to get a dump of all related databases.

If the page just says Done without any further output you probably didn’t create the directories correctly - remove the storage directory in the profile and try again…

Step 6: Convert the data into ICS format

Now the only remaining step is to convert the data into something usable by other programs - we will use iCalendar / ICS files for this purpose.

  1. The required data can be found in the section events.
  2. Just click the button Convert Calendar data to ICS file below that textfield.
  3. Now you can save the converted data using the Save button.

Congratulations, you have made it. You should have a new file called “events.ics”, a standard ICS file containing all your Offline Calendar entries, now - use it with any program you like.


This sounds complicated - isn’t there any easier way

I’m not aware of any - as said Firefox OS doesn’t provide any API for calendar access. Syncto aimed to provide calendar synchronization among others, but as far as I can see only Bookmarks and History synchronization are implemented. Backup and Restore Firefox OS data (and a few others) are essentially doing the same, but don’t provide a way to export the data (i.e. they are missing steps 5 & 6).

I don’t want to upload my data to you!

You won’t - the whole export / conversion process happens locally on your computer.

I don’t understand how to do xxx

Feel free to use the issues section on GitHub and ask away!


The following sites were particularly useful for finding out about Firefox OS’ way of operation:
Hacking FirefoxOS: Excellent information about flashing and building a custom kernel for your Firefox OS phone
Firefox OS Builds, imágenes Vanilla actualizadas para ZTE y Alcatel (Spanish): I found out about / here; links to Firefox OS builds for Alcatel and ZTE phones
Actualización de Firefox OS 1.0 y 1.1 a Firefox OS 1.3 , 1.4 Y 2.0 (Spanish): Another blog with links to Alcatel images
Instalado las roms de Firefox OS (Spanish): And another blog with a detailled flashing guide
iCalendar documentation
IndexedDB: Subdomain Quota Management: Mozilla bug documenting the movement of the IndexedDB directories
idbbrowser: Browse Firefox’s IndexedDB databases used to provide images for different phones, but unfortunately that site doesn’t exist any more.