Porting Replicant to Android 11

Active development has moved towards AOSP 11.

The basic features working on Replicant 9 and 10 have been confirmed to work on Replicant 11, but not everything has been tested yet on either version. The source code and build instruction for both these previous versions have been kept to do regression tracking:


See RunningReplicant11 before installing Replicant 11 on your device to not break it.

Building Replicant 11

Source code

$ repo init -u -b replicant-11-dev
$ repo sync

Alternatively a shallow copy of the source tree can be fetched in order to save on disk space:

$ repo init -u -b replicant-11-dev --depth=1
$ repo sync -c

To unshallow a specific module:

$ cd path/to/module
$ git fetch --unshallow <remote>

While there are no official releases yet, there will be a 11-nlnet-eu-grant-825310-replicant-update tag that freezes the replicant-11 source code in order to enable anyone to review the work done as part of an NLnet grant.

If you want to checkout the source code at this tag, you will need to replace the -b replicant-11-dev in the commands above by -b refs/tags/<tagname>. For example:

$ repo init \
  --depth=1 \
  -u \
  -b refs/tags/11-nlnet-eu-grant-825310-replicant-update

Build dependencies

For Trisquel 8 and 9

sudo apt-get install bc bison build-essential bsdmainutils ccache curl flex g++-multilib gcc-multilib gettext git gnupg gperf imagemagick lib32ncurses5-dev lib32readline-dev lib32z1-dev liblz4-tool libncurses5-dev libsdl1.2-dev libssl-dev libwxgtk3.0-dev libxml2 libxml2-utils lzop python-mako python3-mako pngcrush rsync schedtool squashfs-tools xsltproc zip zlib1g-dev
sudo apt-get install gcc-5-arm-linux-gnueabi

You will also need to install repo as described in the bug #2199.

Fixing the build environment

Allow system binaries for building

By default, the Android 11 build system can only use the prebuilt binaries it ships.

While having binary toolchains is better for reproducible builds, and that the binaries are free software, this creates a number of issues:
  • We need to be able to rebuild the binaries, and so far no one did it yet.
  • Binaries are way harder to trust than source code and not everyone trust Google.

As GNU/Linux distribution's tools can be rebuilt and are easier to trust, we are using that for now.

Java heap space

The Java heap size is automatically set according to the available system memory. On machines with 8 GB or less RAM, it is set to a value which is too low, and will result in the following error during the build:

Exception in thread "main" java.lang.OutOfMemoryError: Java heap space

The heap size can be increased with an envirnoment variable:

$ export _JAVA_OPTIONS="-Xmx3g" 

Reduce parallel jobs to avoid killed processes

Increasing the Java heap space is not enough to get a successful build on machines with 8 GB or less RAM. It is also necessary to reduce the number of parallel jobs, to avoid processes from being killed due to lack of memory. This typically happens during the build of frameworks/base components.

For greater speed, you may let your build run with the defaults, wait for it to fail due to killed processes, and then relunch the build with:

$ make -j1

By default, Ninja, the underlaying build system for Android, used when you run make bacon, computes the number of parallel jobs according to the number of CPUs on your machine (typically #CPUs + 2 parallel jobs).

Launching the build

You can either launch builds with our wrapper script like that:

$ ./vendor/replicant/ i9305

It will try to use all the the CPU cores you have available by using one job per processor + one extra job.

You can also manually launch the build with the usual AOSP commands (so you could adjust the number of jobs with -j for instance):

$ source build/
$ lunch replicant_i9305-userdebug
$ make -j2

Install the images

From scratch

Due to the bug #2235 we can't use the same commands than before with Replicant 9 and 10. Instead we have to install it in a different way:
  • First we need to flash the images with heimdall flash --BOOT boot.img --RECOVERY recovery.img --SYSTEM system.img
  • Then we need to reboot to recovery during the boot by pressing the volume up, menu and power buttons
  • Then we need to select Wipe data/factory reset and then Factory data reset
  • And finally we can boot to Replicant 11 by selecting Reboot the system now

Update previous installation

adb remount
adb sync

Get adb

As the device IDs are the ones given by the Linux kernel, they are not in the adb udev rules, so for now it requires to run adb as root:

$ sudo adb shell
* daemon not running; starting now at tcp:5037
* daemon started successfully
i9305:/ #                                 
$ sudo adb kill-server
$ adb shell
* daemon not running; starting now at tcp:5037
* daemon started successfully
error: no devices/emulators found

So make sure to kill the adb-server and run it as root:
$ adb kill-server
$ sudo adb shell
* daemon not running; starting now at tcp:5037
* daemon started successfully
i9305:/ # 

Boot progress

You can also follow the boot progress with adb:

adb logcat
adb logcat -b main

Note that the device can go into suspend at any time, so adb might be interrupted. That looks like that:
First you get a shell

$ sudo adb shell
i9305:/ #

Then the connection is interrupted:

$ adb shell
i9305:/ # [randomdev@fullyfreelaptop ]$                                                                                                     

The effect with adb logcat is similar.

Getting the latest changes

  • The repositories are being constantly modified with git push --force as we are trying things out, and don't want to make the commits history look too dirty, so be sure to backup your local changes.
  • Sometimes the manifest repository is also modified with git push --force. In that case the following commands will loose all the work you did locally but will make the repository consistent with upstream repositories again:
    $ rm -rf .repo/manifests .repo/manifests.git .repo/manifest.xml
    $ repo init -u -b replicant-11-dev
    $ repo sync --force-sync
  • The following command might also be necessary to make the state consistent with upstream repositories again, when the manifest history wasn't rewritten, but it will also loose all the work you did locally:
    $ repo sync --force-sync

Known working distributions

Distribution Works Comments
Trisquel 8 Yes Tested with an lxc chroot:
* Worked fine before and it buildt images fine
* Doesn't work anymore in LXC in Parabola in due to cgroup API upgrades, it probably still works in chroots or as standalone installation
* Trisquel 8 is also not supported anymore by Trisquel
Trisquel 9 Yes Tested with an lxc chroot:
* Builds images fine
Trisquel 10 ? Upgraded from a Trisquel 9 lxc chroot:
* Seems to build image fine, build from scratch not tried yet.
Debian 10 Yes

Build VM

If you use Parabola, you may be interested in running Trisquel 9 in LXC.

To do that first debootstrap a Trisquel 9 rootfs.

Parabola's debootstrap does support Trisquel 9 and its manual has an example on how to do that for Trisquel 8:

$ man debootstrap
# debootstrap flidas flidas-root

So you just need to change from flidas to etiona:

$ man debootstrap
# debootstrap etiona etiona-root

Then you can use virt-manager to setup the LXC instance.

The advantages of this solution are that:
  • The LXC guest and host shares their resources (CPU, RAM) with almost no penalty
  • Trisquel 9 is not a rolling release distribution
The disadvantage of this solution are that:
  • you need to configure the Trisquel 9 LXC instance (vimrc, sshd_config, etc)
  • It's more complicated to setup
  • The Android build system may outputs a warning message about not being able to use namespaces which may become mandatory in newer Android versions

There is also some information in the Libreplanet wiki about the topic, like with the DistroExecutionEnvironments article.

It makes sense to move the information that are not Replicant specific there (or in another place) to make it easier to coordonate with with other distributions that may need specific FSDG distributions to be built, or software that needs to be deployed in specific distributions.

Known issues

Trisquel 8 and 9

With Trisquel 8 and 9 we have an issue with the repo tool.

It tends to update itself automatically, so you might end in a situation like that:

$ repo --force-sync
repo: error: Python 3 version is too old; Please use Python 3.6 or newer.

Both Trisquel 8 and Trisquel 9 don't have a recent enough python3 to run recent versions of repo.

There is a workaround described in the bug #2199.

Cleanups to be done

  • Make adb work as user by using the right USB IDs, and make userspace do the USB setup.
  • Make the kernel not use hardcoded CMDLINE_FORCE Not possible unless the bootloader is changed or Linux is very heavily patched.
  • Make the kernel not use hardcoded partitions if possible (though we use system as root)
  • Make a clean Gatekeeper HAL module implementation instead of using the same hack than goldfish
  • Look at init.rc documentation to see if init.rc can be overriden clearly with the override statement to see if it's possible to keep the serial console patch for -eng

Upstreaming status

  • The stock bootloader is incompatible with Linux, see BootloadersIncompatibleWithLinux for more information. So we maintain patches to enable the Galaxy SIII, and Galaxy Note II to boot with the stock bootloader. In the long run we need to look into using u-boot in the kernel partition as using u-boot instead of the stock bootloader currently require nonfree and non-redistributable software (BL1).
  • For the patches that are not merged yet, see the issues of the redmine upstreaming sub-project

Graphics status

Progress of the graphics related tasks is tracked at GraphicsReplicant11.

Modem status

libsamsung-ipc: libsamsung-ril:
  • Ported to Replicant 11: it does initialize the modem but Android doesn't find the SIM card yet.
  • Tested and validated under Replicant 6 (doesn't break telephony)
  • Code cleanup is needed

Right now the modem is started then stopped at boot, so to see it boot we need to start it with these commands:

$ sudo adb root
$ adb shell
$ adb start ril-daemon

Then we see the modem boot messages and also samsung-ipc messages arriving with the following command:

$ adb logcat -b radio

It's also possible to run ipc-modem under Android.

Modem status TODO

  • Continue to clean up the libsamsung-ipc and libsamsung-ril patches, test the patches in Replicant 6 when applicable, and merge them in the upstream repositories.
  • Convert the firmware loading driver to the upstream API and then adapt libsamsung-ipc for that. This should also benefit other devices like the Galaxy SIII 4G, and the Galaxy Note II 4G which probably don't need much more to get their modem supported by upstream Linux.
  • Cleanup and convert the rest of the drivers to look like the ones for the Nokia N900 and adapt the userspace in libsamsung-ipc, and merge libsamsung-ipc support for that once the kernel API is stable.
  • Add more tests. We should now have the infrastructure in libsamsung-ipc to use real samsung-ipc messages. In addition it might even be possible to use user mode Linux to do tests now that User mode Linux supports USB, though it requires coding something that sends URBs. User Mode Linux also has issues with i686 that need to be fixed (building on i686 fails, but building for i686 on x86_64 worked last time I tried).


First month of full time equivalent work:

Time estimation Task Comments
DONE boot a device under AOSP9 Only boots with graphics, not much more
7h DONE build it under a FSDG compliant distribution like Trisquel8 WIP for AOSP, It's difficult to do precise time estimations as it could work out of the box or require one full time month of work depending on how much issues are encountered
Builds under Trisquel8
21h DONE * port the changes from AOSP9 to LineageOS 16
* cleanup the code
* build the kernel from the Android build system
* make sure it builds with an FSDG compliant distribution
* document the build procedure

* Boots with adb.
* Has ultra slow graphics
14h find, remove and document proprietary software in LineageOS 16
21h find, remove and document privacy issues in LineageOS 16
7h Add support for the touch keys driver in the galaxy-s3 dts applied
7h upstream the AAT1290 flash led Linux dts for the galaxy-s3 boards Now in 5.3
7h rebrand LineageOS as Replicant
70h port and cleanup the the Galaxy SIII (i9300) modem Linux driver from 4.16 to 5.0 See the modem status for more details
Total: 147h (~1 month)
Second month of full time equivalent work:
* port libsamsung-ril and libsamsung-ipc to Android 9
* Make the modem driver and libsamsung-ipc work together
157h See the modem status for more details
Total 157h ~1 month
Third month of full time equivalent work:
Task Time estimation Comments
port the sensors libraries and other device specific libraries
Look which sensor libraries can be used
70h Already done by the unofficial LineageOS port of the Galaxy SIII (i9300), needs testing
add support for Audio with the upstream kernel driver 70h Might be way faster, depending on what Android 9 uses
See also this bugreport
add partial (no modem) support for the Galaxy SIII 4G (i9305) and factorize the code with i9300 14h * The source code on which the work was based changed from AOSP to an unofficial LineageOS port to a port of i9305 support for AOSP by Joonas to the official LineageOS so it's now supported by default
* The work to factorize the code between the i9300 and i9305 still need to be done
Total 154h ~1 month
Task Time estimation Comments
create a recovery 21h
add internal WiFi support and validate the functionality 6h
add external WiFi dongles support 20h External dongles support might be tricky
create new update the install and upgrade instructions 35h Our current install instructions don't scale as we have one copy for each device.
We also created generic instructions but they tend to be harder to follow1 than the device specific ones.
This will be made in a modular format (for instance in LaTeX) that enables to generate per device install instructions without requiring to have multiples copy of the same text.
The instructions will need to be able to be modified and compiled on an FSDG compliant distribution.
Mostly done:
* The installation instructions are now generic enough.
* Some long standing TODO were also done along the way like adding backup instructions for the EFS.
* The current instructions are still for Replicant 6.0 and will need to be updated for Replicant 9.0
Task Time estimation Comments
Estimate the amount of work to Reduce the attack surface ?
Estimate the amount of work to add in-system upgrades ?

1 The generic instructions were tested at Install parties in Paris

Devices support:

Easy, because it's similar enough to the Galaxy SIII (I9300)

Galaxy Note II (N7100)
Task Time estimation Comments
port the EA8061 LCD Linux driver 35h
port the S6EVR02 LCD Linux driver 35h
port the MAX77693 flash led Linux driver 7h
android: add support for the Note II (N7100) and factorize the code with Galaxy SIII (i9300) and Galaxy SIII 4G (i9305) 14h Should be similar to the Galaxy SIII
port the sensors libraries and other device specific libraries 70h It's difficult to evaluate how much time it could take
add support for Audio with the upstream kernel driver 14h Should be similar to the Galaxy SIII
Galaxy Note 8.0 (N5100) and 8.0 WiFi (N5110)
Task Time estimation Comments
Evaluate the time required to do the port 14h TODO

Needs more work and unknown upstream Linux status

Device Time estimation Comments
Galaxy S II (i9100) Linux: devboard dts upstream? unknown status
Galaxy Note (N7000) unknown Linux upstream status
Galaxy Nexus (I9250) OMAP4, no dts upstream
Galaxy Tab 2 7.0 (P3100), 7.0 WiFi (P3110), 10.1 (P5100), 10.1 WiFi (P5110)
GTA04 >= A4 TODO: a RIL needs to be written, userspace GPS support is missing, audio scenarios, etc


Replicant 6.0 changes

See Replican6Changes.

Other rebases

See the Samsung-ipc page.

Other attempts

  • It might be interesting to contact the people doing ports once we have something working well enough.
  • It is also interesting to look at other attempts to understand if a given device is powerful enough to run Android 9 and what configuration was used to achieve it.
Device(s) Repository status Comments
i9300 CustomROMs * February 8 2020 Pie release
i9300 Team InFusion * August 20 2019 Pie release Issues: * Uses a Samsung kernel
* Uses too many nonfree libraries
=> Probably nothing we could reuse from its code
n7100 ComicoTeam * January 4 2020 Pie release
i9100 rINanDO * March 20 2020 Pie release
* July 19 2020 Android 10 release

Links for other attempts

CustomROMs i9300 components

Repository Tree path Dependencies Function Comments
lineage-16.0 branch
hardware/samsung/macloader Loads the MAC Address of the WiFi network interface Might be useful
hardware/samsung/wifiloader Loads the wifi kernel module (like modprobe) and setup firmware filesystems permissions May be useful
hardware/samsung/audio seems to contains ril related stuff as well Look if the ril stuff is required, go for standard audio
hardware/samsung/lineagehw/hidl/livedisplay livedisplay is a feature similar to what redshift does on GNU/Linux Not sure if it works with mainline
hardware/samsung/exynos/multimedia/utils/ seem meant for audio/video decoding offload assembly obtimized color conversion and resize code check assembly code license, not sure if useful
all other directories in hardware/samsung/exynos/ nonfree firmwares, nonfree software?, smdk kernel? audio/video decoding offload Avoid using that
hardware/samsung/exynos3 nonfree firmwares?, nonfree software?, smdk kernel? some light libraries, display stuff (gralloc, etc), 2D acceleration (FIMG), camera (FIMC), 3D acceleration, etc Avoid using that for now

Known error messages that are safe to ignore

  • TestHarnessModeService: Failed to start Test Harness Mode; no implementation of PersistentDataBlockManagerInternal was bound
  • JniUtils: Could not load native library jni_latinimegoogle


Updated by dl lud 3 months ago ยท 34 revisions

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