[Samsung Galaxy S8 Questions and Answers] Tachi91:
I've had this Samsung phone for maybe a month and a half. So please take this with a grain a salt. Information that was scattered around and I had to go searching for when I bought this phone. Here is my brain dump...

There isn't an AOSP or Vanilla Android ROM, they're all touchwiz based. Most of the ROMs give you an option during installation of certain apps you can remove. I dabbed around making a very clean and minimal ROM, but turns out if you remove too much the setup wizard falls apart and the phone basically freezes before even selecting your language. So I resorted to installing someone elses ROM and after setting it up, using ROM toolkit to remove random system apps and hoping it doesn't crash after a reboot. haha

This is my first Samsung phone (exynos S8) so getting around to using ODIN and the different files you need to flash was a headache. The general rules to follow are.

1. Enable Developer Options and turn on OEM Unlock. Then never again change that option. If you are not running 100% stock the bootloader will prevent the phone from turning on correctly and kick you into Download mode basically forcing you to flash a stock ROM. So once you turn on OEM Unlock, just leave it turned on. I was messing around in Dev Options and without knowing turned it off. Next time I restarted my phone I was forced to flash stock rom again. Custom ROMS tend to remove that option entirely so someone doesn't mistakenly turn it OFF.

2. KNOX is Samsungs security in stock ROMs. The moment any kind of custom recovery or anything is installed. KNOX will be tripped and stop the phone from completing boot up. It'll basically tell you that theres something that wasn't signed by Samsung and to reset the phone. An endless cycle unless you, 1. Install a Custom ROM or 2. Flash a stock ROM to undo whatever you did.

3. Keep your firmware (modem bootloader etc) as recommended by the ROM Dev. AQF7 is the last known stable and developed for firmware.

Right now there a new update AQG5 that has an updated Bootloader that will softbrick your phone. People have tried installing the entire Stock ROM and ran into issues. It worked for some, but avoid it for now. If you do find the need to play with it. For the time being flashing just the modem (CP file) and keeping or using the previous AQF7 Bootloader (BL file) should keep your phone usable.

4. The S8 and S8+ are very much identical except the obvious size difference. Cross Development allows Devs to create a single ROM for both devices. With only the Kernel being the difference. Which is some cases both are in the ROM zip and automatically selected for you. So if they state its compatible with both. If not just focus on S8+ only ROMS.

5. ODIN is a program that's used to flash files. Either to flash custom recovery or stock files. Samsungs SmartSwitch program is like Windows Phone Recovery Tool. It'll detect the phone you have connected and download the latest stock ROM it can find and flash it. ODIN is a stripped down program that we use to flash individual files. Its only really used to either flash a stock ROM or custom recovery. In some cases bootloaders and modem updates, but id avoid those for now.

6. ROM/Firmware structure. Samsung stock ROMs and Firmware zips are available all over the place. Basically its a .zip file with more tar files in it.

Lets say you download a stock ROM.

The name is normally Model|Region|Version.zip so for me I have G950FXXU1AQF7 that tells you. G950F is the Euro S8 Exynos, XXU1 is basically just New Zealand and some carrier, AQF7 is the firmware version. The file name might have multiple regions. Theres more into what means what. I personally just focus on the Model and the Firmware. I can delete carrier apps or flash my carriers CSC later on. From what I've seen version numbers increase with the next letter in the alphabet and a number. So obviously an update with AQF7 is newer then one named AQD6 etc.

If you where to extract a stock firmware/ROM zip to use in ODIN etc. It normally gets broken down to these tar files. If stock files are renamed ODIN will not accept them. It happen to me

BL** - Contains the Bootloader, partition layout etc.

AP** - Actual ROM. Kernel, System, cache, userdata (for some), recovery

CP** - Modem files.

CSC** - Preloaded carrier apps, settings. This comes in two files. If you flash HOME_CSC your data is kept if you decide to do an update. CSC file without HOME will format the data partition.

These files are flashed in their prepacked files. You wont flash individual system, kernel files etc with odin.

7. TWRP the go to recovery for Android. You'll use ODIN to flash it. On twrps website just find the S8+ (dream2lte) and download the .tar file. Using ODIN it will be flashed as an AP file.

8. Once you have TWRP installed it will trip KNOX if using a stock ROM. The button combination to get you into recovery from a fully turned off phone is,

PWR + Vol Up + Bixby

Vol Down is Download Mode, also used as the button combo to force the phone to restart. If you restart it this way, quickly move your finger and hit Vol Up and if done right will go into recovery.

9. CSC is carrier bloatware, but in the forums its what gives you VoLTE & WifiCalling. As long as your carrier supports it and in an area/wifi network that will allow it. Some ROMs have it included, if not you can find a forum thread which offers a flashable zip that will give you all the carriers around the globe. If selected correctly should give you those features for your carrier on your phone.

___________

The jist of all that is. Enable OEM unlock > use ODIN to flash TWRP > Boot into TWRP and flash a custom ROM. You'll use TWRP to flash ROMS, Mods, Custom Kernels. ODIN/SmartSwitch would be used to revert to 100% stock. If you ever some how turn off OEM unlock while using a custom ROM. FAP will be turned on and block you from using your phone until you flash a stock ROM and turn on OEM unlock again.

I'm personally using Renovate ICE on my S8 and have removed ALOT of system apps. Windows Phone has a special place in my heart, but Microsoft is just terrible about it now. I had a 950XL for a bit, but always had HTC phones when it came to Android. For me HTC was so much easier to work with when it came to ROMs. Now I'm rocking an S8 so had to learn fast.

Always do your research before flashing anything. Make sure multiple sources say the same thing or risk flashing something that might break your phone. If any other user finds something I mention to be wrong, PLEASE correct me. I will learn and so will others.

What I missed from HTC forums was the sticky threads. The go to threads that broken everything down and explained it. All the HTC phones I had while using XDA had these sticky threads in each devices forums. I was and still am reading threads from other Galaxy phones just to get a better understanding of how it all works since they aren't in this devices forum.

Not to talk bad about long time Samsung users, but yall need to get organized haha. Once I'm confident with Samsungs inner programming workings I'll try to make an actual knowledge thread with links and where credit is do. But dam it's like sink or swim around some galaxy phones.