Each Stock OS comes with its own firmware. What we observed when we were testing upgrading our devices to Pie was once we flashed stock Pie if we tried to revert to the previous version of the ROM - stock oreo or nougat the device went into a bootloop. There were changes made to the partitions which made it incompatible with our older OS versions. This we saw in almost all Xiaomi devices.So ideally you should move forward with the OS to avoid boot loops or weird device behavior. Though there were exceptions for e.g. in Fairphone we did not see such issues going back and forth on OS versions. Xiaomi also has anti rollback implemented on some models like whyred which will brick the device if rolled to a previous OS.
1 Like
Seems like something manufacturer-specific, then?
Currently 14 Android 9-Pie versions are listed: from December 2018 update to November 2019 security update. What PDA code (build version) did your 9-Pie firmware have?
I didn’t take note of that.
The s9 I saw is apparently 960f/ds, and comes with android 9. Could the latter one create some bootloop or any other problems when flashing e?
I’m not sure I understand you correctly. But if your SM-G960F comes with Android 9 firmware version 9/10/11/12-2019, then - yes, I assume that. But opinions are different like the experiences of the /e/ users, e. g. → here and → here.
The ephone support team (ephone_support@e.email), which is responsible for the premium refurbished smartphones with /e/ pre-loaded, should be able to provide us with binding information. They sell Samsung S7 / S7 Edge and S9 / S9+
A better situation can be expected from spring 2020: v1-pie /e/ branch & “LOS 17.0 for /e/ will be after we upgrade present set of devices and v1 which is scheduled for spring 2020”
1 Like
Hi @archie, thanks for taking the time to explain and for showing other users experience. To be honest, after reading them, I feel quite discouraged again to try to flash it on my own. Maybe its best for me to wait until the /e/asy installer is developed so non tech savvy people like me can flash without so many issues.
@graz, changing the operating system isn’t witchcraft. Nevertheless it requires careful work and it’s advisable to know what you are doing.
The current problem is that since the beginning of 2018, Samsung has been constantly increasing the security features of devices with Android 8.0.0 or higher with every update. According to Samsung, this of course only serves to protect the user, but of course also to make it more difficult for the user to change operating systems.
The fact that especially Samsung devices like the S7, which currently still work with /e/ OS e-0.7-n (nougat) and cannot cope with the updated bootloaders from Oreo 8.0.0, will change when the above mentioned upgrades are available. In a few weeks the issue will be off the table!
But until the release of e-pie, you have the possibility to use a stablies unofficial Lineage-16.0-for-microG “herolte” from Jan. 2020. LOS 16.0 has no problems with Oreo 8.0.0 bootloaders …
1 Like
Hi,
I’m new to /e/ and was looking forward to install /e/ on my new S9 however the post of graz made me hesitate to do so. The response from archie confused me a bit since graz was talking about an S9 while the response mentions an S7.
Now if I understand correctly the problem is that if your device runs a recent stock Android version it comes with a bootloader version that is incompatible with the latest /e/ version, or partition changes are made as Manoj states. Is this true for both the S7 and the S9?
My S9 has a firmware version from 2019-11 and I think this contains bootloader version 7. I assume that I’m not able to install /e/ or end up in a bootloop. Is that correct?
I do wonder though would Updates to the Dev and Stable branches fix things?
Thanks in advance for any clarification.
1 Like
Hi @0x7C0 updates to Dev and stable branches are still on the same OS which is Oreo. If you are coming from a higher OS version it may have issues on some devices. You would have to wait for an /e/ OS official or unofficial build of the same OS level as your current stock ROM.
2 Likes
@0x7C0, what applies to the Galaxy S7 SM-G930F (e-0.7-nougat) does not necessarily apply to the Galaxy S9 SM-G960F (e-0.8-oreo). But I am looking for clarification.
But as @Manoj speaks from his experience, it can be »If you are coming from a higher OS version it may have issues on some devices.« Last certainty is only given when the operating system change to /e/ OS ROM was successful.
This information → here the conclusion can be drawn that /e/ OS ROM e-0.7-oreo (S9 · SM-G960F) and StockROM Android 9-pie S9 (G960FXXS7CSJ3) are much better compatible than /e/ OS ROM e-0.7-nougat (S7 · SM-G930F) and StockROM Android 8-Oreo S7 (G930FXXS7ESL9).
These are the same requirements as for @ Fab2B. Accordingly, the chances are good that a successful OS change to /e/ OS e-0.7-o- dev (oreo) can be accomplished.
My exact baseband-version is G960FXXU7CSJ5 and I think I’m gonna give it a shot this weekend. Thanks for the effort!
Successfully installed /e/ so can confirm it works for baseband version: G960FXXU7CSJ5. 
1 Like
In the meantime I also changed two devices (S7 and S7 Edge) with different OS versions of StockROM Oreo 8.0.0 to /e/ OS e-0.7-nougat. Problems probably only occur from device to device. Compare again "it can be" … Now I have learned it myself, that it works but also doesn’t work.
Hi @0x7C0 Im glad to hear that you installed /e/ succesfully!
Did you use the installation guide in the wiki or some other way?
If I undesrtood correctly, you have an s9, G960F, bootloader version 7. What android version was installed before flashing?
Thanks
Hi @graz. I’ve mainly followed the instructions on the wiki. Except for the order of executing the ‘patch the device section’. That’s what brought me to this forum in the first place since I didn’t completely understand that based on previously flash experiences 
I’ve also had to sideload the vendors. There was only one strange thing and that was after sideloading the /e/ zip and wanted to restart the phone (latest step in the instruction) I got a warning that there was no OS installed. Restarted anyway and apparently there was an OS since /e/ started up. All in all in was quite a smooth experience.
The previous Android version was 9. Stock and up to date (to 2019-11).
1 Like
It’s the part from the instruction that doesn’t seem to be needed on every device so I first tried it without. But then indeed the installation did fail so I had to execute that as well. (Although I’m not really sure what it does exactly)
On some devices, installation can fail if vendors are not up-to-date. In this case, please:
Download those vendors
Install them
On the device, go into Advanced > ADB Sideload, then swipe to begin sideload
From the computer, please run adb sideload <vendors file>