Replicant » Upstreaming patches

h1. Android distributions

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h2. Reviews

h3. Anbox

*Manifest*: https://github.com/anbox/platform_manifests/blob/anbox/default.xml

*Android base*: 7.1.1_r13

*Based on*: AOSP

Goals:

 * Run Android (applications) in containers on top of GNU/Linux

Extra repositories (overridden or added):

| path                       | URL                                                           | Comments |

| art                        | https://github.com/anbox/platform_art                         |          |

| bionic                     | https://github.com/anbox/platform_bionic                      |          |

| frameworks/av              | https://github.com/anbox/platform_frameworks_av               |          |

| frameworks/base            | https://github.com/anbox/platform_frameworks_base             |          |

| frameworks/native          | https://github.com/anbox/platform_frameworks_native           |          |

| frameworks/opt/net/wifi    | https://github.com/anbox/platform_frameworks_opt_net_wifi     |          |

| hardware/libhardware       | https://github.com/anbox/platform_hardware_libhardware        |          |

| hardware/libhardware_legacy| https://github.com/anbox/platform_hardware_libhardware_legacy |          |

| system/core                | https://github.com/anbox/platform_system_core                 |          |

| system/netd                | https://github.com/anbox/platform_system_netd                 |          |

| system/vold                | https://github.com/anbox/platform_system_vold                 |          |

| vendor/anbox               | https://github.com/anbox/anbox                                |          |

h3. Android x86

At the time of writing, the most recent images are RC images for Android 9, but there are branches for Android 10.

As they use (mostly?) upstream kernels, they sometimes have interesting code.

*Source code*: https://git.osdn.net/view?a=project_list;pf=android-x86

*Manifest*: git://git.osdn.net/gitroot/android-x86/manifest.git

Branches[1]: 

| Branch | Android version |

| q-x86 | 10.0 |

| pie-x86 | 9.0 |

| oreo-x86 | 8.1 |

| nougat-x86 | 7.1 |

| marshmallow-x86 | 6.0 |

| lollipop-x86 | 5.1 |

| kitkat-x86 | 4.4 |

| jb-x86 | 4.3 |

| ics-x86 | 4.0 |

| honeycomb-x86 | 3.2 |

| gingerbread-x86 | 2.3 |

| froyo-x86 | 2.2 |

| eclair-x86 | 2.1 |

| donut-x86 | 1.6 |

| cupcake-x86 | 1.5 |

fn1. https://www.android-x86.org/source.html

h3. AOSP

AOSP doesn't support many devices, but it seem to support some devboards. 

The advantage is that in general devboards are well supported by upstream kernels.

Supported devboards[1]?:

| Devboard | Freedom issues | Comments |

| Beagleboard-X15 | No free GPU driver | Well supported by GNU/Linux, free bootloader |

| Cuttlefish emulator | ? | ? |

| Other | ? | ? |

The official documentation also "mentions some devboards":https://source.android.com/setup/build/devices .

fn1. Some of the devboards in this page are probably supported: https://wiki.linaro.org/AOSP#AOSP_Dev_Board_Reference_Information

h3. AOSP Mainline

*website*: https://github.com/aospm

*manifest*: https://github.com/aospm/android_local_manifests/blob/main/aospm.xml

Repositories:

| Path                  | URL                                                    | Comments             |

| device/generic/sdm845 | https://github.com/aospm/android_device_generic_sdm845 | Use prebuilt kernels |

| external/tinyhal      | https://github.com/aospm/tinyhal                       | Generic HAL[1]       |

| external/vibrator-ff  | https://github.com/aospm/external_vibrator-ff          | Generic HAL[1]       |

fn1. https://aosp-developers-community.github.io/#generic-hal-efforts

h3. CustomROMs

CustomROMs seem to be a space for unofficial port of LineageOS. The idea is probably to develop the port until they manage to meet LineageOS's "device-support-requirements.md":https://github.com/LineageOS/charter/blob/master/device-support-requirements.md . When the requirements are met, they are probably included in LineageOS directly.

Interesting ports:

* The Galaxy SIII (GT-I9300) is being ported to more recent LineageOS versions. There is "a thread on the collaboration with Replicant":https://github.com/CustomROMs/android_local_manifests_i9300/issues/1 in github. The person/people doing the port seem to alternate between an upstream kernel and a older kernel based on the vendor code depending on the amount of work required to finish the port and/or the difficulties encountered. As we are also using a kernel based on upstream Linux we collaborate on that part by reusing each other work when applicable.

h3. DivestOS Mobile

This distribution is based on LineageOS. While they seem to reuse nonfree software to make the hardware work, they spent some time cleaning up LineageOS code itself.

For instance it contains patches to remove privacy issues and nonfree software included in CyanogenMod or LineageOS.

As we need to do that too in Replicant as long as we use LineageOS as base, it would be interesting to collaborate more with DivestOS on that part.

Web site:

*https*: https://divestos.org/

*Onion*: http://6sdlxbqgcxdbkvysoir2qvqqs5ro3fxgyl3phvuphcdyklv7rg57jhid.onion

h3. Fairphone

As October 2020, they are porting the Fairphone 2 to Android 9. However to do that, they are using 3.4 kernel and not any upstream kernels.

In addition, they don't seem very interested in free software bootloaders, and the Fairphone 1 and 2 use Qualcomm System On a Chip.

However they are probably interested in free software libraries to make the port to newer Android versions easier.

h3. GLODroid

*Based on*: AOSP

*Manifest*: https://github.com/GloDroid/glodroid_manifest/blob/master/glodroid.xml

h4. device/glodroid repository

*url*: https://github.com/glodroid/glodroid_device.git

Content:

| Path                                         | description                             | Comments                                                |

| common/                                      | * low memory configuration

                                                 * selinux policies

                                                 * Other (TODO)                          |                                                         |

| hals/power/                                  | power management (DVFS, CPU boost, etc) |                                                         |

| hals/usb-aidl/                               |/2. USB gadget HAL                       |/2. It seems to use the same API than our scripts.

                                                                                              It also look very generic (for instance it uses

                                                                                              the Google/Android VID/PID).                         |

| hals/usb-gadget/                             |

| platform/kernel/kernel.mk                    | Kernel build system                     | Can it be moved?                                        |

| platform/uboot/uboot.mk                      | u-boot build system                     | Can it be moved?                                        |

| pinephone/lights/                            | LEDS HAL                                | Is there a generic LED HAL ?                            |

| pinephone/reference-ril/                     |/2. AT ril based on the reference RIL    |/2. We could use it for now, until we manage to use QMI  |

| pinephone/rild/                              |

| pinephone/vibrator/                          | Vibrator HAL                            | AOSP Mainline has a separate vibrator                   |

h4. Forked repositories

| Path                              | URL                                                    | Comments |

| external/libcamera                | https://github.com/glodroid/glodroid_forks.git         |          |

| external/boost                    | https://github.com/glodroid/glodroid_forks.git         |          |

| external/libyaml                  | https://github.com/glodroid/glodroid_forks.git         |          |

| external/libyuv_chromium          | https://github.com/glodroid/glodroid_forks.git         |          |

| external/iio-sensors-hal          | https://github.com/glodroid/glodroid_forks.git         |          |

| external/minigbm                  | https://github.com/glodroid/glodroid_forks.git         |          |

| external/drm_hwcomposer           | https://github.com/glodroid/glodroid_forks.git         |          |

| external/mesa3d                   | https://github.com/glodroid/glodroid_forks.git         |          |

| external/u-boot                   | https://github.com/glodroid/glodroid_forks.git         |          |

| external/tinyhal                  | https://github.com/glodroid/glodroid_forks.git         |          |

| kernel/glodroid-megous            | https://github.com/glodroid/glodroid_forks.git         |          |

| kernel/glodroid-megous-edge       | https://github.com/glodroid/glodroid_forks.git         |          |

| kernel/glodroid-broadcom          | https://github.com/glodroid/glodroid_forks.git         |          |

| kernel/glodroid-stable            | https://github.com/glodroid/glodroid_forks.git         |          |

| kernel/glodroid-modules/rtl8189es | https://github.com/glodroid/glodroid_forks.git         |          |

| kernel/glodroid-modules/rtl8189fs | https://github.com/glodroid/glodroid_forks.git         |          |

h4. Toolchains repositories

| Path                                                         | URL                                                  | Comments |

| prebuilts/gcc/linux-x86/arm/gcc-linaro-arm-linux-gnueabihf   | https://github.com/glodroid/linaro_gcc_prebuilts.git |          |

| prebuilts/gcc/linux-x86/aarch64/gcc-linaro-aarch64-linux-gnu | https://github.com/glodroid/linaro_gcc_prebuilts.git |          |

| prebuilts/gcc/linux-x86/arm/gcc-linaro-arm-eabi"             | https://github.com/glodroid/linaro_gcc_prebuilts.git |          |

| prebuilts/gcc/linux-x86/or1k/gcc-linux-or1k"                 | https://github.com/glodroid/linaro_gcc_prebuilts.git |          |

h4.  bootloader related repositories

| Path                                         | URL                                                        | Comments |

| external/crust-firmware/arm-trusted-firmware | https://github.com/crust-firmware/arm-trusted-firmware.git |          |

| external/crust-firmware/crust                | https://github.com/crust-firmware/crust.git                |          |

h4. Other repositories

It also contains various repositories for nonfree firmwares and nonfree bootloader components (BL1, etc), and a repository with just APKs (this might be an issue for license compliance).

h3. LineageOS

See "device-support-requirements.md":https://github.com/LineageOS/charter/blob/master/device-support-requirements.md for more information on LineageOS expectations.

Replicant has "a script":https://git.replicant.us/replicant/vendor_replicant-scripts/tree/research that is able to parse the "LineageOS wiki data":https://github.com/LineageOS/lineage_wiki . That can be useful to find information on devices supported by LineageOS.

The "devices supported by LineageOS 16":https://wiki.lineageos.org/devices/ have either:

* A Qualcomm SOC with an integrated modem inside (MSM*) for many devices

* A Qualcomm SOC without a modem inside (APQ*) for many devices

* A HiSilicon Kirin 970 SOCs for devices like:

** The "Huawei Honor View 10":https://wiki.lineageos.org/devices/berkeley

** The "Huawei P20 Pro":https://wiki.lineageos.org/devices/charlotte

* A Samsung Exynos 7580 SOC for the following device

** "Galaxy S5 Neo":https://wiki.lineageos.org/devices/s5neolte (Smartphone): It has shared memory between the modem and the SOC

It may be because they rely on nonfree software to support devices, which has not been ported to Android 9, or may be because they need more time to add devices with other SOCs like exynos.

h3. Waydroid

Waydroid consist in some host tool that can containerize an Android distribution, and some changes on top of LineageOS.

Some repositories would only be useful if we decide to integrate Waydroid in Replicant to have some FSDG compliant way to run Android applications on top of GNU/Linux:

* The audio library does something like that: @snd_pcm_open(&out->pcm, "pulse", SND_PCM_STREAM_PLAYBACK, 0);@ [1], so if I understood right, it uses Pulseaudio's alsa compatbility layer.

* For the graphics, some repositories like mesa, minigbm are replaced by Waydroid's own repositories. It also integrates boringdroid APK as-is instead of building it from source. Boringdroid brings moving windows to Android instead of the default full-screen windows.

There is some interest in Guix about having something like that as a "patch serie":https://issues.guix.gnu.org/51737#22 was sent for adding the Waydroid host part in Guix.

What would be more interesting for Replicant as-is that in android_hardware_waydroid[2], there is libraries that work with upstream kernels like the vibrator library. We also have our own vibrator library but it would probably be a good idea to share the maintenance somehow.

fn1. https://github.com/waydroid/android_hardware_waydroid/blob/lineage-18.1/audio/audio_hw.c

fn2. https://github.com/waydroid/android_hardware_waydroid

h3. Building a collaboration with other Android distributions

Given that:

* Replicant doesn't want to support devices that have more freedom issues than the ones currently supported.

* Many other Android distributions probably don't have the same goals with the freedom of the devices they support.

* Replicant 9 is based on upstream Linux and will have to maintain its userspace libraries.

* Some users may still want to support devices that have more freedom issues than the ones supported by Replicant.

It could be a good idea to share the maintenance of the code used to make Replicant 9 with other distributions.

h2. Comparison

h1. Comparison of distributions

h2. AOSP and LineageOS

| Feature | AOSP | LineageOS |

| Code quality | Better than LineageOS | |

| Documentation | Better than LineageOS | |

| root | Not sure if supported or not | Supported |

| Minor release versioning | supported with Git tags | Not supported.

For instance frameworks/native has no LineageOS tags (only cm-1x tags) and has no other branch for lineage OS 16.0 than the lineage-16.0 branch, as the other branches name are for other things. This was confirmed after running 'git fetch github' in frameworks/native to fetch the other branches that are not fetched by repo by default.

Despite that, some code was even merged in after the lineage-16.0 release:

<pre>

commit 22abc3cf4077644463a2dc1c59a5a74e9518ea16

Merge: 9e96d54 8a6b6c3

Date:   Sat Jul 13 18:57:45 2019 +0200

    Merge remote-tracking branch 'aosp/pie-gsi' into lineage-16.0-pie-gsi

</pre> |

| GUI features for developers

* Advanced reboot | ? | Supported |

| Integrated kernel builds | Unsupported | Supported |