[DEV][EXYNOS][Discussion] Kernel 80% bug and other samsung "features" - Samsung Galaxy S8 & S8+ Cross Device Development

Hey,
I've been thinking about starting development of a kernel on S8+, but I've heard that there are issues such as charge not going above 80% and some other stuff I don't even remember anymore but I did read about it.
Can somebody point me to patch to allow over 80% charge with tripped knox or is this issue non existent with latest source?
What other things would I need to do to have a kernel working just like stock minus knox features?
How would I go about "deknoxing" kernel?
How can I trick kernel to say that knox isn't tripped?
Sorry if that's not the right section but I couldn't really find a better place to ask this while getting a good amount of replies. If this isn't the right section, mods, please move it. First samsung device I've ever owned so I'm stepping into new grounds for me aswell.

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olokos said:
Hey,
I've been thinking about starting development of a kernel on S8+, but I've heard that there are issues such as charge not going above 80% and some other stuff I don't even remember anymore but I did read about it
Can somebody point me to patch to allow over 80% charge with tripped knox or is this issue non existent with latest source?
What other things would I need to do to have a kernel working just like stock minus knox features?
How would I go about "deknoxing" kernel?
How can I trick kernel to say that knox isn't tripped?
Sorry if that's not the right section but I couldn't really find a better place to ask this while getting a good amount of replies. If this isn't the right section, mods, please move it. First samsung device I've ever owned so I'm stepping into new grounds for me aswell.
Click to expand...
Click to collapse
I'm not 100% convinced it's in the kernel. Meerly swapping the abl.elf combo with the stock one your device refused to boot but will charge to 100%. This happens when I have the combo boot.img and the stock abl, so.
In everything for SD can be stock firmware except abl, devcfg, recovery, and boot. This is how I package my firmware for both my samfail installs and my just better firmware standalone.
Basicallay, unless you have Samsung private key, you won't be making kernels that solve that problem for the people in which it matters.
Oh, and answering the patch question: nothing in their released kernel source has anything on this. And whatever abl is it's closed source and looks encrypted, so we haven't gotten far that direction either

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olokos said:
Hey,
I've been thinking about starting development of a kernel on S8+, but I've heard that there are issues such as charge not going above 80% and some other stuff I don't even remember anymore but I did read about it.
Can somebody point me to patch to allow over 80% charge with tripped knox or is this issue non existent with latest source?
What other things would I need to do to have a kernel working just like stock minus knox features?
How would I go about "deknoxing" kernel?
How can I trick kernel to say that knox isn't tripped?
Sorry if that's not the right section but I couldn't really find a better place to ask this while getting a good amount of replies. If this isn't the right section, mods, please move it. First samsung device I've ever owned so I'm stepping into new grounds for me aswell.
Click to expand...
Click to collapse
It all depends on what s8+ model you have to better answer your question. The snapdragon version in USA has locked bootloaders so we can't use custom kernels. The kernel we are forced to use is a factory kernel that has selinux set to permissive on boot. this allows security to be relaxed enough for root to work. On exynos version, they have unlocked bootloaders. they can flash custom kernels and recovery.

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I'm talking about exynos version. Is 80% battery bug related only to snapdragon devices?
I know that I can't get knox back, that's due to efuse popping the moment we trip knox, I was just talking about faking it in download mode etc.

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Yeah, 80% is rooted US Snapdragon S8/S8+ right now. Maybe part abl.elf, part boot.img responsible; abl may start it and hands the baton to sbin healthd binary, which then utilizes the inbuilt scaling of the kernel battery driver.
---------- Post added at 04:14 PM ---------- Previous post was at 03:42 PM ----------
The funny thing is I would never have purchased an S8+ if US carrier ones were Exynos, because Exynos doesn't perform as well in truly custom rooms due to Samsung not releasing Exynos source code--or so I've heard. Kind of ironic, I guess: purchase something that would perform better in truly custom ROMs for that very reason, but soon discover is completely unable to be utilized with any truly custom ROM!

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olokos said:
I'm talking about exynos version. Is 80% battery bug related only to snapdragon devices?
I know that I can't get knox back, that's due to efuse popping the moment we trip knox, I was just talking about faking it in download mode etc.
Click to expand...
Click to collapse
knox stats can somewhat be hidden in rom, but download can't be fooled. it checks by sending voltage to efuse with it knows what it should be.

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MrSteelX said:
knox stats can somewhat be hidden in rom, but download can't be fooled. it checks by sending voltage to efuse with it knows what it should be.
Click to expand...
Click to collapse
What do you mean? What does misrepresenting 0x1 in download mode help with?
You can absolutely fool download mode, and as it turns out it's not very smart tLll.
Samfail will forever proof of that

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partcyborg said:
What do you mean? What does misrepresenting 0x1 in download mode help with?
You can absolutely fool download mode, and as it turns out it's not very smart tLll.
Samfail will forever proof of that
Click to expand...
Click to collapse
It helps with nothing apart for the looks. I've also heard that in some services they just check it like that and based on this they tell you if you still have warranty or not, so why not?
Question is how to fake it or where's the code regarding this located.

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jhofseth said:
Yeah, 80% is rooted US Snapdragon S8/S8+ right now. Maybe part abl.elf, part boot.img responsible; abl may start it and hands the baton to sbin healthd binary, which then utilizes the inbuilt scaling of the kernel battery driver.
---------- Post added at 04:14 PM ---------- Previous post was at 03:42 PM ----------
The funny thing is I would never have purchased an S8+ if US carrier ones were Exynos, because Exynos doesn't perform as well in truly custom rooms due to Samsung not releasing Exynos source code--or so I've heard. Kind of ironic, I guess: purchase something that would perform better in truly custom ROMs for that very reason, but soon discover is completely unable to be utilized with any truly custom ROM!
Click to expand...
Click to collapse
Exynos variants are the ones with unlocked bootloader and sources, there we have now AOSP ROM under alpha development and custom ROMs
Sent from my SM-N950F using Tapatalk

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jhofseth said:
Yeah, 80% is rooted US Snapdragon S8/S8+ right now. Maybe part abl.elf, part boot.img responsible; abl may start it and hands the baton to sbin healthd binary, which then utilizes the inbuilt scaling of the kernel battery driver.
---------- Post added at 04:14 PM ---------- Previous post was at 03:42 PM ----------
The funny thing is I would never have purchased an S8+ if US carrier ones were Exynos, because Exynos doesn't perform as well in truly custom rooms due to Samsung not releasing Exynos source code--or so I've heard. Kind of ironic, I guess: purchase something that would perform better in truly custom ROMs for that very reason, but soon discover is completely unable to be utilized with any truly custom ROM!
Click to expand...
Click to collapse
Well you heard incorrectly. Android/touchwiz are based off the Linux kernel. Linux kernel is licensed under the gpl, gpl (GNU public license) makes providing the source code for any project making use of gpl'd software mandatory.
Technically they don't have to give the source away for free, but given gpl anyone who purchased it could then offer it for free legally. Samsung's hands are tied when it comes to this. Companies have been taken to court by the fsf/eff and lost in the past.
Sure they could hire a team of lawyers and fight it for years, bit at the cost of losing whatever credibility they have left with the Android community.
Also what "sources" do you speak of? Kernel source? That's been out for ages. "Drivers"? Part of the Linux kernel, see above.
Do mean some kind of touchwiz ui toolkit? Most custom roms dont do tw anyway and aosp is wide open, so I'm not sure why that would matter a lot

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From what I've heard defconfig changes are enough to do "deknoxing".
What about faking knox status? How would I go about faking it in kernel itself?

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maybe outdated link
partcyborg said:
Well you heard incorrectly. Android/touchwiz are based off the Linux kernel. Linux kernel is licensed under the gpl, gpl (GNU public license) makes providing the source code for any project making use of gpl'd software mandatory.
Technically they don't have to give the source away for free, but given gpl anyone who purchased it could then offer it for free legally. Samsung's hands are tied when it comes to this. Companies have been taken to court by the fsf/eff and lost in the past.
Sure they could hire a team of lawyers and fight it for years, bit at the cost of losing whatever credibility they have left with the Android community.
Also what "sources" do you speak of? Kernel source? That's been out for ages. "Drivers"? Part of the Linux kernel, see above.
Do mean some kind of touchwiz ui toolkit? Most custom roms dont do tw anyway and aosp is wide open, so I'm not sure why that would matter a lot
Click to expand...
Click to collapse
https://www.xda-developers.com/samsung-exynos-and-aosp-explained-a-story-of-betrayal/
This is probably outdated now. In the past Samsung has done stuff like say they could choose GPL or BSD and choose BSD.

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jhofseth said:
https://www.xda-developers.com/samsung-exynos-and-aosp-explained-a-story-of-betrayal/
This is probably outdated now. In the past Samsung has done stuff like say they could choose GPL or BSD and choose BSD.
Click to expand...
Click to collapse
Yea that really sucks that they pull that ****. Unfortunately the eff/fff are the only organizations that have the resources necessary to successfully prosecute a gpl violation case. It's been done before but it's costly and time consuming so I think it's typically a method of last resort so when these companies drag their feet they get away with it as they publish something eventually and it's hard to conclusively prove its not complete unless something glaringly obvious is missing. Ususally at least what gets put out is usually enough to at least build a pure oss implementation.
Fun fact: the SN-G950U kernel source as published by Samsung doesn't even compile as is :laugh: there are silly syntax/include errors in a few places. There is also a zip file inside that looks to be another copy of at least part of the kernel source with VZW in its name but the actual zipfile is corrupted lol. It's too bad that there aren't requirements on how it gets released, just that the code is somehow available.

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Q: Can somebody point me to patch to allow over 80% charge with tripped knox or is this issue non existent with latest source?
A: This is only on Snapdragon variants. Due locked BL you cant even use a custom kernel.
Q: What other things would I need to do to have a kernel working just like stock minus knox features?
A: I dont understand this question. What would there be broken? You need a different libsecurestorage lib to fix WiFi/Hotspot + disable securestorage from default.prop & You need modded camera firmware files by geiti94 or jesec.
Other than that toolchains could break VoLTE (according to some other kernel devs), so stick to Google's 4.9 tc. You have enough kernels out there for the E8995 to see yourself what needs fixing (i.e. camera etc.).
Q: How would I go about "deknoxing" kernel?
A: Disable it from defconfig; tima, knox, rkp etc.
Q: How can I trick kernel to say that knox isn't tripped?
A: Use resetprop in ramdisk with an init script that will fake the knox status into 0x0. Or just code it inside the cmdline of the kernel and dont worry about resetprop ever again.

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Noxxxious said:
Q: Can somebody point me to patch to allow over 80% charge with tripped knox or is this issue non existent with latest source?
A: This is only on Snapdragon variants. Due locked BL you cant even use a custom kernel.
Q: What other things would I need to do to have a kernel working just like stock minus knox features?
A: I dont understand this question. What would there be broken? You need a different libsecurestorage lib to fix WiFi/Hotspot + disable securestorage from default.prop & You need modded camera firmware files by geiti94 or jesec.
Other than that toolchains could break VoLTE (according to some other kernel devs), so stick to Google's 4.9 tc. You have enough kernels out there for the E8995 to see yourself what needs fixing (i.e. camera etc.).
Q: How would I go about "deknoxing" kernel?
A: Disable it from defconfig; tima, knox, rkp etc.
Q: How can I trick kernel to say that knox isn't tripped?
A: Use resetprop in ramdisk with an init script that will fake the knox status into 0x0. Or just code it inside the cmdline of the kernel and dont worry about resetprop ever again.
Click to expand...
Click to collapse
The above isnt quite true. The combination factory image results in max 80% charge for all devices including exynos. The difference is because the exynos isn't bootloader locked the permissive selinux and dm-verity off for system aren't necessary for root like they are for snapdragon.
For example, a root that does not trip Knox like SamFail will require using the combo rom which will be 80% max charge.
So 80% max or 0x1, you pick
Re: knox
I'm not sure what the above poster is referring to, but getting rid of knox with the combo kernel is as simple as changing a few build.prop lines and removing some system apps. Sure there are still files on the machine that have the word knox in them, but knox the security tool is completely gone, it does not even appear in your about phone section. Absolutely no other software or other functionality is affected. This is how every sampwnd and samfail root user has their device configured.

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partcyborg said:
The above isnt quite true. The combination factory image results in max 80% charge for all devices including exynos. The difference is because the exynos isn't bootloader locked the permissive selinux and dm-verity off for system aren't necessary for root like they are for snapdragon.
For example, a root that does not trip Knox like SamFail will require using the combo rom which will be 80% max charge.
So 80% max or 0x1, you pick
Re: knox
I'm not sure what the above poster is referring to, but getting rid of knox with the combo kernel is as simple as changing a few build.prop lines and removing some system apps. Sure there are still files on the machine that have the word knox in them, but knox the security tool is completely gone, it does not even appear in your about phone section. Absolutely no other software or other functionality is affected. This is how every sampwnd and samfail root user has their device configured.
Click to expand...
Click to collapse
There is no choice in 80% max or 0x1 because OP wants to create a custom kernel, therefore no factory binary boot.img will be used that limits your cap.
Also the question states how to deknox the kernel and not the rom.

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Noxxxious said:
There is no choice in 80% max or 0x1 because OP wants to create a custom kernel, therefore no factory binary boot.img will be used that limits your cap.
Also the question states how to deknox the kernel and not the rom.
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Click to collapse
Lol then there is no option at all for snapdragon, as custom kernels are not possible.

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partcyborg said:
Lol then there is no option at all for snapdragon, as custom kernels are not possible.
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Click to collapse
Yep, title of the thread states Exynos so I dunno where all the snapdragon talk came from
Anyway I hope that the OP knows enough now to start his journey. Goodluck!

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Noxxxious said:
Yep, title of the thread states Exynos so I dunno where all the snapdragon talk came from
Anyway I hope that the OP knows enough now to start his journey. Goodluck!
Click to expand...
Click to collapse
Lol what journey? As stated here these "features" don't exist

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@partcyborg it's a nice way of saying that I can now start development as all my questions were answered by @Noxxxious
Cheers mate!