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Downgrading Galaxy S8 (Exynos) - Bootloader version question

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xAxB

Member
Mar 9, 2017
30
7
I have my reasons for wanting a device that runs Android 7, but can that subsequently be upgraded to Android 8 (and above), and I am thinking that a second hand Galaxy S8 might do the job.

However, since I am looking at second hand phones, there is no guarantee that it would actually be on Android 7 (unless the online shop is willing to check for me), and I am just wondering if, in the instance where the phone comes with Android 8 or above, would I be able to flash it back to Android 7, or would it be dependent on bootloader version. And if it is bootloader version dependant, which version would allow me to downgrade back to Android 7?

Thanks.
 

spawnlives

Senior Member
Jan 27, 2018
1,070
403
Samsung Galaxy S8
Samsung Galaxy S9
I have my reasons for wanting a device that runs Android 7, but can that subsequently be upgraded to Android 8 (and above), and I am thinking that a second hand Galaxy S8 might do the job.

However, since I am looking at second hand phones, there is no guarantee that it would actually be on Android 7 (unless the online shop is willing to check for me), and I am just wondering if, in the instance where the phone comes with Android 8 or above, would I be able to flash it back to Android 7, or would it be dependent on bootloader version. And if it is bootloader version dependant, which version would allow me to downgrade back to Android 7?

Thanks.
On the S8 android version 7 has a binary ( bootloader ) version 1. Early version of Oreo has a binary ( bootloader ) 1 as well ie: beta and next few upgrades. I can't remember exactly when the version 2 binary ( bootloader ) was introduced, might have been 3 or 4 version of Oreo before being stable.
If looking for a 2nd phone that can by downgraded to android 7 you will need bl version 1. Anything with bl version 2 and higher can not be downgraded to android version 7.
You can check in settings - about phone - software information - Baseband version. Binary ( bootloader ) number will be the 5th number/letter from the right, you can also check build number as well.
 
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xAxB

Member
Mar 9, 2017
30
7
On the S8 android version 7 has a binary ( bootloader ) version 1. Early version of Oreo has a binary ( bootloader ) 1 as well ie: beta and next few upgrades. I can't remember exactly when the version 2 binary ( bootloader ) was introduced, might have been 3 or 4 version of Oreo before being stable.
If looking for a 2nd phone that can by downgraded to android 7 you will need bl version 1. Anything with bl version 2 and higher can not be downgraded to android version 7.
You can check in settings - about phone - software information - Baseband version. Binary ( bootloader ) number will be the 5th number/letter from the right, you can also check build number as well.

Thanks a lot. Do you know if custom ROMs, for instance Lineage also update the baseband as you go up versions?

The second hand shop I was looking at update everything they sell with the latest available update and I suspect that is common practice. So I am thinking that the best option for me would be to sacrifice the e-fuse on my Samsung S7 with Android 7.0, and start playing with various Android versions / ROMs. However, I may want to go back to Android 7.0 on that phone eventually, so it is important that I don't accidentally mess that up.
 

spawnlives

Senior Member
Jan 27, 2018
1,070
403
Samsung Galaxy S8
Samsung Galaxy S9
Thanks a lot. Do you know if custom ROMs, for instance Lineage also update the baseband as you go up versions?

The second hand shop I was looking at update everything they sell with the latest available update and I suspect that is common practice. So I am thinking that the best option for me would be to sacrifice the e-fuse on my Samsung S7 with Android 7.0, and start playing with various Android versions / ROMs. However, I may want to go back to Android 7.0 on that phone eventually, so it is important that I don't accidentally mess that up.
I normally use stock rom's as some of my apps don't work well with custom roms. Usually the only time that i've installed a custom roms is if someone else is having trouble with the installation process then i revert back to stock.

The Baseband ( in about phone ) will always show the current version of the OS whether it's stock or custom that you are on ( including updates ).

As far as i know custom roms do not increase you bootloader version number. So you should be able to revert back to the current stock rom that your on. You can always check bootloader version in Download ( odin ) Mode.

If you have any questions you should ask in the custom roms section for more information.
 

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    I have my reasons for wanting a device that runs Android 7, but can that subsequently be upgraded to Android 8 (and above), and I am thinking that a second hand Galaxy S8 might do the job.

    However, since I am looking at second hand phones, there is no guarantee that it would actually be on Android 7 (unless the online shop is willing to check for me), and I am just wondering if, in the instance where the phone comes with Android 8 or above, would I be able to flash it back to Android 7, or would it be dependent on bootloader version. And if it is bootloader version dependant, which version would allow me to downgrade back to Android 7?

    Thanks.
    On the S8 android version 7 has a binary ( bootloader ) version 1. Early version of Oreo has a binary ( bootloader ) 1 as well ie: beta and next few upgrades. I can't remember exactly when the version 2 binary ( bootloader ) was introduced, might have been 3 or 4 version of Oreo before being stable.
    If looking for a 2nd phone that can by downgraded to android 7 you will need bl version 1. Anything with bl version 2 and higher can not be downgraded to android version 7.
    You can check in settings - about phone - software information - Baseband version. Binary ( bootloader ) number will be the 5th number/letter from the right, you can also check build number as well.