LineageOS Changelog 19: Massive Improvements For A/B Devices, Lineage Recovery & More

The LineageOS team regularly takes out time and pens blog posts to make it easier for users to know about the new features and changes. Today, LineageOS published their 19th changelog. It has been nearly two months since the last changelog post, so there's a lot to cover.

LineageOS have been working on bringing support for dual partition A/B devices. The major challenge in the development of custom ROMs for such devices is the lack of a dedicated recovery partition (which is present in all phones that shipped with Marshmallow or an older Android version). These devices don't need a recovery partition because there are two copies of almost all partitions. Out of the two copies of each partition, only one is active at a time. When an OTA update has to be installed, it is applied to the inactive partition copies. To let the user use the updated operating system, the inactive partition copies have to be activated. This can't be done on the fly. So, after the update has been installed to the inactive copies, the user is prompted to perform a reboot, following which the inactive and active partitions are switched. The dual partitions help in the seamless installation of updates and if an OTA update fails to boot, the device can fallback to the partitions that were active in the previous boot.

The Updater app on LineageOS now supports addon.d compatible mods. There is a /system/addon.d folder in LineageOS which stores scripts which are run when the ROM is updated. Since the Updater app is now compatible with addon.d scripts, it will now be able to run them after the ROM is updated. This means that seamless installation of updates will now be possible on LineageOS.

Older addon.d scripts, deemed as addon.d-v1, are compatible with only single partition devices. For the seamless installation of updates on A/B devices, addon.d-v1 scripts may not work. Instead, addon.d-v2 scripts are required. According to the LineageOS team, the current addon.d script for Open Gapps is "too complicated" and will not be able to install the Gapps seamlessly. LineageOS's MindTheGapps are addon.d-v2 compatible, so you can use them instead. Magisk is v2 compatible too. This means if you have rooted LineageOS on your phone, the Magisk installation will be retained after an update.

For making sure that your mods are compatible with the seamless installation of updates, you have to follow the instructions below. These instructions are quite different from what you would be used to, but because dual-partition devices are the norm these days, the following instructions will become the new standard.

• Boot a custom recovery (either fastboot booting, or flashing and then booting will do)
• Wipe Data
• Flash LineageOS
• Reboot to Recovery (it is important you reboot to the installed recovery, which will be Lineage Recovery - more on this one later - unless you hand flashed another, which is not recommended for A/B devices)
• Install whatever addon.d-v2 compliant mods you’d like to (please note that OpenGApps is not addon.d-v2 capable yet)
• Reboot
• Enjoy!

If you attempt to install GApps/Mods to system in the same boot as LineageOS, thanks to slot logic, none of it will persist. You need to reboot to recovery between flashing the ROM and any mods, however, do not reboot to OS between ROM flash and other mods.

Worthwhile note, if at any point you wish to go back a build, you can always run “fastboot set_active other” and jump back to the last/other slot, which houses the last update you had.

Lineage Recovery

As mentioned before, A/B devices don't have a recovery partition. The recovery image for such devices is built into the boot image. When you flash a ROM on a dual partition device, the existing recovery is overwritten. The recovery that is built into the ROM is usually that of AOSP. To save the users from the effort of reflashing the custom recovery, LineageOS will be shipping their own recovery in their ROM.

Lineage Recovery is based on the AOSP recovery and has several features on top of it. The SELinux is set to as Enforcing, so the operations performed in the recovery would be secure. If the internal storage of your device is encrypted, you will not be able to access the internal storage. This means you will not be able to flash any other ROM or mods. You will have to make use of ADB to sideload packages and take backups.

Lineage Recovery will soon be available for single partition devices.

Major Changes

The following major changes have been made to LineageOS in the past two months:

Changelog

• Trust interface has been added. Check out our previous blog post to know more about it
• Added SMS limit warning to Trust: whenever a higher volume of SMS messages is sent, you will be asked to manually confirm that you want to send that message. This prevents malicious apps to send spam SMS draining your mobile credit
• More granular Trust warnings controls
• You can now optionally force legacy apps to use the full screen size on 18:9 devices. This can be configured per app as this might break some apps that are not properly written
• Optional black style: now you can make the dark UI style completely black
• Data toggle in quick settings on 15.1 has now gotten the data usage view back (restored functionality from 14.1)
• Introduced Lineage Recovery (for A/B devices only at the moment - more on this later)
• Updater has been improved, especially for A/B devices
• The su addon now supports A/B devices
• The addon.d backup / restore system now support A/B devices
• Signal icons and carrier text can be hidden for disabled SIMs
• July security patches have been merged (15.1)
• June security patches have been merged (both 14.1 and 15.1 devices)

Changes To Leadership

For the last nine years, the LineageOS team was led by ciwrl. However, "to spend more time offline", ciwrl has stepped away from the role of director and he will be replaced by haggertk as the ninth director.

Supported Devices

LineageOS now supports sixteen more devices for its Oreo-based release. One device (Galaxy S7/Edge) has been added to the Nougat-based 14.1 roster. Meanwhile, the HTC One A9 and Galaxy S4 Mini have been dropped.

The following devices are now supported by LineageOS:

• Asus Zenfone 2 Laser (720p) 
• Asus Zenfone 2 Laser/Selfie (1080p)
• Google Nexus 4  
• Google Nexus 5X  
• Google Nexus 6  
• Google Nexus 6P  
• Google Nexus Player  
• Google Pixel C  
• HTC One A9  
• LeEco Le Max 2  
• LeEco Le Pro 3  
• Lenovo P2 
• Motorola Moto Z  
• Motorola Moto Z2 Force 
• Nvidia Shield Android TV 
• OnePlus One 
• Oppo Find 7a and 7s
• Oppo R5 
• Oppo R7s
• Oppo R7 plus 
• OnePlus 2  
• OnePlus 3/3T  
• OnePlus 5  
• OnePlus 5T  
• Samsung Galaxy S5 
• Samsung Galaxy S5 Active 
• Samsung Galaxy S9 Exynos  
• Samsung Galaxy S9+ Exynos 
• Samsung Galaxy Tab S2 8.0 Wi-Fi (2016)  
• Samsung Galaxy Tab S2 9.7 Wi-Fi (2016)  
• Sony Xperia XA2 
• Wingtech Redmi 2 
• Xiaomi Mi 5  
• Xiaomi Mi 5s  
• Xiaomi Mi 5s Plus  
• Xiaomi Mi 6  
• Xiaomi Mi Mix 2  
• Xiaomi Mi Note 2  
• Xiaomi Redmi Note 4 Snapdragon 
• Xiaomi Mi A1 
• Xiaomi Mi Mix
• Xiaomi Redmi Note 5 Pro

Source: LineageOS

Krittin Kalra

Krittin Kalra is a 20 year old Android freak. Striving for passions, chasing down his dreams and living a life without regrets is his sole mantra. A bit moody, he also does custom ROM reviews for AndroGuider. Currently pursuing his B.Tech, he aspires to follow his heart.