Porting Replicant to Android 9¶

• Table of contents
• Porting Replicant to Android 9
  • LineageOS 16
    • Repositories and changes for LineageOS 16
    • Building LineageOS 16 version
      • Source code
      • For Trisquel 8
      • Launching the build
      • Getting lastest changes
      • Install the images
      • Get adb
      • Booting
    • cleanups to be done
    • Using SwiftShader instead of Mesa3D llvmpipe for software rendering
  • AOSP 9
    • Status with AOSP 9
    • Repositories and changes
    • Building AOSP version
      • Source code
      • For Trisquel 8
      • Building it
      • Trisquel 8 LXC
  • Upstreaming status
  • Modem status
    • Modem status TODO
  • TODO
    • Devices support:
      • Easy, because it's similar enough to the Galaxy SIII (I9300)
      • Needs more work and unknown upstream Linux status
  • Documentation
    • Replicant 6.0 changes
    • Other rebases
  • Other attempts
    • Links for other attempts
    • CustomROMs i9300 components
  • Links

LineageOS 16¶

Repositories and changes for LineageOS 16¶

• https://git.replicant.us/GNUtoo/kernel_replicant_linux.git
• git://git.putti.eu/aosp/external_mesa3d.git
• https://git.replicant.us/GNUtoo/android_build.git
• https://git.replicant.us/GNUtoo/device_i9305.git
• https://git.replicant.us/GNUtoo/manifest.git
• https://git.replicant.us/GNUtoo/vendor_replicant.git

Building LineageOS 16 version¶

Source code¶

$ repo init -u https://git.replicant.us/replicant-9/manifest.git -b replicant-9
$ repo sync

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

$ repo init -u https://git.replicant.us/replicant-9/manifest.git -b replicant-9 --depth=1
$ repo sync -c

To `unshallow` a specific module:

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

For Trisquel 8¶

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 pngcrush rsync schedtool squashfs-tools xsltproc zip zlib1g-dev
sudo apt-get install gcc-5-arm-linux-gnueabi

Launching the build¶

Follow the i9300 manifest instructions:

$ subject='/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com'
$ mkdir .android-certs
$ for x in releasekey platform shared media testkey; do \
  ./development/tools/make_key .android-certs/$x "$subject"; \
  done
$ parallel_tasks=$(echo "$(grep 'processor' /proc/cpuinfo | wc -l ) + 1" | bc)
$ source build/envsetup.sh
$ lunch lineage_i9305-eng
$ make -j${parallel_tasks} bacon

The images can then be flashed with heimdall. They are then in:

  out/target/product/i9305/obj/PACKAGING/target_files_intermediates/lineage_i9305-target_files-eng.replicant/IMAGES/

Getting lastest 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/ # This enables me to force push and rebase the manifest repository as well
  $ repo init -u https://git.replicant.us/replicant-9/manifest.git -b replicant-9
  $ 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
  

Install the images¶

$ sudo heimdall flash --BOOT out/target/product/i9305/obj/PACKAGING/target_files_intermediates/lineage_i9305-target_files-eng.replicant/IMAGES/boot.img --USERDATA out/target/product/i9305/obj/PACKAGING/target_files_intermediates/lineage_i9305-target_files-eng.replicant/IMAGES/userdata.img --SYSTEM out/target/product/i9305/obj/PACKAGING/target_files_intermediates/lineage_i9305-target_files-eng.replicant/IMAGES/system.img 

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

$ adb kill-server
$ sudo adb shell
* daemon not running; starting now at tcp:5037
* daemon started successfully
i9305:/ # 

Booting¶

At some point during boot, the device goes into suspend, so you will need to press some buttons like the power or volume button to make the boot continue until the graphical interface.

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.

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

Using SwiftShader instead of Mesa3D llvmpipe for software rendering¶

To use SwifShader you need a kernel that supports UDIV/SDIV emulation, you can checkout the branch GNUtoo/udiv-emulation for kernel/replicant/linux. After doing that that run the following commands to use SwiftShader:

$ adb remount
$ adb shell
i9305:/ # rm vendor/lib/egl/libGLES_mesa.so # or move it somewhere safe meanwhile you test SwiftShader
i9305:/ # nano system/build.prop # set ro.hardware.hwcomposer=ranchu and ro.hardware.gralloc=default
$ adb reboot

AOSP 9¶

Status with AOSP 9¶

• The Galaxy SIII 4G (i9305) boots (with graphics hacks) under AOSP9, without having to import nonfree libraries:
  • The device boots until the lock screen
  • The graphics work but are really slow as they have not been optimized
  • Sometime the display content is corrupted
  • The touchscreen works
• The kernel used is based on Linux 5.0-rc6 and has ~150 Android specific patches on top and some patches for the Galaxy SIII 4G (i9305) on top

Repositories and changes¶

• git://git.putti.eu/aosp/manifest_i9305.git
• git://git.putti.eu/aosp/kernel_i9305.git
• git://git.putti.eu/aosp/device_i9305.git
• git://git.putti.eu/aosp/external_mesa3d.git
• git://git.putti.eu/aosp/build_make.git
• git://git.putti.eu/aosp/core.git

Building AOSP version¶

Source code¶

First get the source code:

$ repo init -u git://git.putti.eu/aosp/manifest_i9305.git -b android-9.0.0

For Trisquel 8¶

sudo apt-get install git-core gnupg flex bison gperf build-essential zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev x11proto-core-dev libx11-dev lib32z-dev libgl1-mesa-dev libxml2-utils xsltproc unzip bc python-mako gcc-5-arm-linux-gnueabi

Building it¶

Once this is done, see the device/putti/i9305/README.md for the build instructions.

Trisquel 8 LXC¶

If you use Parabola, you may be interested in running Trisquel 8 in LXC.

To do that first debootstrap a Trisquel 8 rootfs.

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

$ man debootstrap
[...]
# debootstrap flidas flidas-root http://archive.trisquel.info/trisquel

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

• The LXC guest and host shares their resources (CPU, RAM) with almost no penalty
• Trisquel 8 is not a rolling release distribution

• you need to configure again the Trisquel 8 LXC instance (vimrc, sshd_config, etc)
• It's more complicated to setup
• The Android build system output a warning message about not being able to use namespaces which may become mandatory in newer Android versions

Upstreaming status¶

• Unbreak 5.2 booting: This is really tricky as to work with the stock bootloader we'd have to disable the caches and the MMU. We need to look if upstream u-boot would accept something like that. Else we'd need to maintain a stub it.
• add flash support to galaxy-s3 boards Made it in 5.3
• Battery charging:
  • mfd: max77693: Add defines for charger current control : No response
    safe.
  • power_supply: max77693: Listen for cable events and enable charging : No response
  • DangerousBatteryChargerExperiments: Add a way to safely disable battery charging via sysfs.
• ARM: dts: add touchkey nodes for midas Merged upstream

Modem status¶

• Fully tested under GNU/Linux only
• Can initialize completely the modem and receive messages (see the #1954 bug report for the logs)
• Needs more cleanup but there is now a better abstraction

• Ported to Replicant 9 using a wrapper for the API >=12 in libsamsung-ril source code that needs to be removed
• Tested under Replicant 9 without up to date libsamsung-ipc (no modem init)
• Tested and validated under Replicant 6 (doesn't break telephony)

Modem status TODO¶

• Implement the missing part to shut down the modem, close the interfaces and such, in order to need to reboot after each test.
• 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.
• Test the code under Replicant 9 when the graphics status will enable to have decent enough speed to do some testing through human interaction.

TODO¶

First month of full time equivalent work:

¹ The generic instructions were tested at Install parties in Paris

Devices support:¶

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

Needs more work and unknown upstream Linux status¶

Documentation¶

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.

Links for other attempts¶

• https://www.xda-developers.com/android-pie-android-9-port-custom-roms/

CustomROMs i9300 components¶

Links¶

• Android build requirements - hardware and software
• Why LineageOS Developers are building Android Go-optimized custom ROMs
• Android Go recommended default values for propreties for optimization
• Team InFusion i9300 optimized system.prop
• Hack to fix high CPU usage caused by logd
• Use low-end video codecs
• Optimize ActivityManager cached apps
• Use 1Gb Dalvik config