Though Samsung will not update Galaxy S5 to Android 8.0 Oreo officially, users can still enjoy latest and sweetest Android 8.0 Oreo via custom ROMs like LineageOS 15. An unofficial version of LineageOS 15 is now available for Galaxy S5 (code-named klte), which you can install via TWRP custom recovery and experience the new features. Interested users check out the guide below.
Recently Google released Android 8.0 Oreo update for Pixel and Nexus devices and also made available Android Oreo Source code. Developers are now busy building ROM based on Oreo and many devices, including the Galaxy S5 have already got Android 8.0 Oreo build via unofficial LineageOS 15 (official LineageOS 15 is not yet released).
An XDA member afaneh92 has released an initial build of LineageOS 15 ROM for Samsung Galaxy S5, which you can install via TWRP recovery. However, the ROM is not ready for daily use as many things (Home button, Camera, Bluetooth and more) are not working as expected.
Experienced users can try out the ROM right now. However, before flashing the ROM, please backup your data and your EFS folder.
Installation Instruction for Unofficial LineageOS 15 on Galaxy S5
Disclaimer: Follow the instruction at your own risk. We will not be liable if any damage occurs to your device and/or its components. It is recommended for technically talented users only.
1. Flash latest custom recovery (TWRP) via Odin (if you have not already).
3. Boot Galaxy S5 into TWRP recovery by pressing Home + Power + Volume up button at the same time.
4. In recovery, select ‘Wipe’ and then wipe data, cache partition and format system.
5. Now, select ‘Install’ and then select the ROM zip file and flash it.
6. If you want Google apps, download Gapps zip file [here] and flash it via TWRP and then reboot your device.
Note: It should take less than 10 minutes until it boots. Any question? Leave it in the comment section below (Source – XDA)