Develop Bugs

[Q] Wiping Cache from Recovery? *PLEASE HELP*

Upon booting up via Vol. Down + Power, there are four options (fastboot, recovery, wipe cache, and simunlock). What happens when you wipe cache?
I just installed a new ROM (well updated), couldnt get it to boot as I was stuck on the custom boot screen, but after wipe cache it loads up?
Does this effect the functionality at all? Please help. Thanks

I believe this is a factory wipe, but is a dumbed down version, that does not wipe /sd-ext partitions etc. Just removes /data programs and user info, but won't touch any /system applications.
It is used to reset the phone without actually booting up the OS

Any particular reason why my ROM wouldnt boot up normally but requires a cache wipe in order to boot?

trenwei said:
Any particular reason why my ROM wouldnt boot up normally but requires a cache wipe in order to boot?
Click to expand...
Click to collapse
Soms roms will require you to wipe dalvik cache in order for the new rom to boot (conflicts can be caused), and wiping this cache would do it, however you can just wipe dalvik cache from recovery not this hboot menu.
For future reference when changing roms, especially when changing to someone elses rom (and especially especially when its a different base) you should be doing a full wipe
A full wipe is:
-Data (factory reset)
-Dalvik Cache
-Ext partition (although sometimes you can get away with skipping this one)
You should be able to wipe those three from both Amon-RA and Clockwork Mod recoveries.

NOTE: I am sleep deprived, so this will proberly not make alot of sense
I'm not that technical with the Android system (have worked with linux abit though)
Deleting the cache would remove any saved data from the system. These saved items may contain anything from images to which default program is loaded, to which widgets are loaded on the homscreen.
This is why after a new install the phone takes a little longer booting up, creating all the new files. If you need me to go into cache, use Google.
Another theory would be:
After an upgrade, some files and apps think that the system has changed owners, so their permissions change from read/write to read/only etc.
With this, some system files will become inaccessible, will be unable to be edited and so forth.
A way around this would be to "fix" the permissions of the data, changing the owner of the files allowing read/write permissions
Rom Manager has a nice little feature that allows you to fix permissions, and has come very helpful for me, with my switching to and from OD/Pinky, and restoring LauncherPro, which likes to FC at every restore -.-.

[Q] Question regarding flashing rom

I tried searching didnt get specific answer I am needing. I have been flashing roms for about 1 year. Its possible I have been messing it up, although my phone has always worked correctly (CM of different flavors). I usually use the following:
hboot/recovery
wipe dav/factory reset/wipe battery stats
install rom
now I am trying very hard not to make things more difficult for another user. I am trying to flash a sense rom Stock Plus v2.1.
In the install instructions it states:
Full Wipe and Flash Instructions:
Make a Nandroid Backup of your current rom
Reboot into ClockworkMod
Choose "wipe data/factory reset"
Go into "mounts and storage" menu and choose "format /boot" and confirm
Choose "format /system" and confirm
Go back to main menu and choose "install zip from sdcard"
Browse your sdcard for the rom zip and flash!
**Note: I know there are a million methods that folks say to follow for a full wipe, including: wiping dalvik, wiping cache, etc. Let me explain why that's unnecessary. The "wipe data/factory reset" option erases your /data, /cache and /data/data partitions, so doing the "wipe cache" option would be redundant. Dalvik-cache is just a folder that resides on the /data partition (Already cleared, remember, so redundant again). The ONLY 2 partitions, that effect the wipe, and were not already cleared are /boot and /system. I've changed roms quite a bit and this method is fast and works everytime.
I read the note but am confused. I have not heard of the things in red above. Could someone explain what I have been doing wrong, or why that would need to be done for rom to function properly? Thanks

Aerysana said:
I tried searching didnt get specific answer I am needing. I have been flashing roms for about 1 year. Its possible I have been messing it up, although my phone has always worked correctly (CM of different flavors). I usually use the following:
hboot/recovery
wipe dav/factory reset/wipe battery stats
install rom
now I am trying very hard not to make things more difficult for another user. I am trying to flash a sense rom Stock Plus v2.1.
In the install instructions it states:
Full Wipe and Flash Instructions:
Make a Nandroid Backup of your current rom
Reboot into ClockworkMod
Choose "wipe data/factory reset"
Go into "mounts and storage" menu and choose "format /boot" and confirm
Choose "format /system" and confirm
Go back to main menu and choose "install zip from sdcard"
Browse your sdcard for the rom zip and flash!
**Note: I know there are a million methods that folks say to follow for a full wipe, including: wiping dalvik, wiping cache, etc. Let me explain why that's unnecessary. The "wipe data/factory reset" option erases your /data, /cache and /data/data partitions, so doing the "wipe cache" option would be redundant. Dalvik-cache is just a folder that resides on the /data partition (Already cleared, remember, so redundant again). The ONLY 2 partitions, that effect the wipe, and were not already cleared are /boot and /system. I've changed roms quite a bit and this method is fast and works everytime.
I read the note but am confused. I have not heard of the things in red above. Could someone explain what I have been doing wrong, or why that would need to be done for rom to function properly? Thanks
Click to expand...
Click to collapse
Assuming you are talking about formatting system and boot? If so, cm is different than sense roms, and this data needs to be wiped. The fact that you have been using cm for so long, explains why you haven't had issues with your wipe method. The data has just been overwriting itself, which doesn't work when going from aosp to sense, or vice versa.
Sent from my ADR6300 using xda premium

actually I have 2 different phones. both are htc inc orig, 2 different users. my personal phone has cm. I do not format boot or system and never have. however, when reading about flashing stock plus v2.1 on the other dinc that is freshly rooted with nothing ever having been flashed, it said to do what was highlighted in red (format boot and system). I had never heard of that.
okay, so format boot and system are needed if you are going from asop to sense (did not know that guess I got lucky). So is it still necessary to format boot and system before flashing on a dinc that was just rooted last night and nothing has been done other than rooting? stock is sense, the rom i would like to flash to the newly rooted phone is sense, so it is or is not needed?
I guess it comes down to what is exactly being wiped/formatted in the following:
data wipe/factory reset
format boot
format system
Yeah I guess thats what im trying to ask. Maybe if I understand what those areas are, then I can better understand why they would need to be wiped/formatted.
Oh and thank you for your reply, I do appreciate the help, and maybe im a bit slow in my thinking today. So please bear with me.

The boot and system files/data take on different characteristics and can be stored differently, depending on the base of the Rom. Base being froyo, gingerbread, Dinc2, Evo, aosp, etc. Things are stored in different places, which means new roms need these areas cleared before flashing in order to work properly.
Edit: Most of these roms have been ported from other devices. If flash instructions are provided, it is best to follow them for best results.
Sent from my ADR6300 using xda premium

okay i think i understand. will do it. thanks for taking the time to help. sometimes it takes me a few to get it sorted out.

Clean Flash Custom Rom

I know I saw this process in a recent thread but I've misplaced it. If anyone can point me to it, I would be grateful.
I want to clean flash CM 13 on my OP3.
From what I remember, I'm supposed to store the CM 13 zip file and gapps file in the SD Card folder. Is that truly correct? The OP3 doesn't have an SD Card though I did find a folder.
If I do a factory reset and wipe everything, won't that folder also get wiped? Then how would I install the ROM from the phone?
Sorry, I know this is a straightforward process for many of you, and dirty flashing is easy. But I think a clean flash is better and I'd rather not guess and end up with a bricked phone I have to fuss with.
Again, I know this exact process is in a thread somewhere but I can't find it.

the phone storage is /sdcard/
u can use something like ES File Explorer and create a folder called CM13 or whatever u want
u do have ur bootloader unlocked and twrp installed, correct?
yes u will just the get cm zip file and put it in a folder (ex. /sdcard/CM13/)
i put the gapps in the same folder
create a nandroid backup
wipe/advance wipe - wipe caches/data/system !!!!Do NOT WIPE - INTERNAL STORAGE OR OTG!!!
then flash cm zip and gapps

Hi, thank you. Yes, bootloader unlocked, twrp installed and I've done it in the past on a different phone but couldn't sort out clean flashing from dirty flashing. I've done it correctly in the past, and it's also gone very wrong for me. I think I mistakenly wiped internal storage once and that was a disaster.
Somewhere I've also read about a factory reset through trwp.
I don't need to do that, or wiping caches/data/system is the same thing?
.

digger16309 said:
Hi, thank you. Yes, bootloader unlocked, twrp installed and I've done it in the past on a different phone but couldn't sort out clean flashing from dirty flashing. I've done it correctly in the past, and it's also gone very wrong for me. I think I mistakenly wiped internal storage once and that was a disaster.
Somewhere I've also read about a factory reset through trwp.
I don't need to do that, or wiping caches/data/system is the same thing?
.
Click to expand...
Click to collapse
If you wipe internal storage, you will lose the zips for your ROM and GAPPS. You can connect your device and have it recognized on your PC from within TWRP if you do accidentally wipe your internal storage.
Factory reset doesn't wipe the system partition as that would remove your OS. Most Roms will wipe your system partition before it installs itself so generally you don't have to wipe the system partition manually, but it's good practice.
Clean flash = wipe dalvik, cache, data; then install ROM (which will wipe system before it installs, or manually wipe system before the ROM install for good measure).
Dirty flash = flash ROM, then wipe dalvik and cache. The only time you should do this if the ROM you're looking to flash says it can be done (ie. CM nightlies).

How do I erase everything on galaxy s3 i747

Hi,
I have i747 that has a clockworkmod recovery. How do I erase as much as possible of everything so that my phone is as clean as possible before I install a new ROM on galaxy s3?
I tried to factory reset phone, did all the 'delete/erase' options within clockworkmod recovery (except advanced section) and yet I see some residual folders from the previous installation. is there a way to completely erase wipe out everything without bricking the phone?
Thanks!

user-747 said:
Hi,
I have i747 that has a clockworkmod recovery. How do I erase as much as possible of everything so that my phone is as clean as possible before I install a new ROM on galaxy s3?
I tried to factory reset phone, did all the 'delete/erase' options within clockworkmod recovery (except advanced section) and yet I see some residual folders from the previous installation. is there a way to completely erase wipe out everything without bricking the phone?
Thanks!
Click to expand...
Click to collapse
You should really flash TWRP recovery before proceeding. CWM hasn't been maintained or updated in a long time. It is likely to give you problems flashing anything new.
To completely blank a phone in TWRP I use Wipe -> Advanced Wipe -> Dalvik, Cache, System, Data. Followed by Wipe -> Format Data then type "yes" to confirm; always a good idea if you're switching between Touchwiz and AOSP in particular. That will leave you with totally blank internal storage. You'll have to flash a ROM from an external SD, or load a ROM zip over USB while booted in recovery because internal storage will be wiped clean.
It might be a good idea to look into what bootloader and modem you're running too. If you're still using CWM, you might be on pretty old firmware that isn't going to work right with newer roms. Just don't start flashing bootloaders/modems willy-nilly. Samsung made this phone kind of easy to hard brick on the newer firmwares. There's a right way to update it, if you find you have to.

jason2678 said:
You should really flash TWRP recovery before proceeding. CWM hasn't been maintained or updated in a long time. It is likely to give you problems flashing anything new.
To completely blank a phone in TWRP I use Wipe -> Advanced Wipe -> Dalvik, Cache, System, Data. Followed by Wipe -> Format Data then type "yes" to confirm; always a good idea if you're switching between Touchwiz and AOSP in particular. That will leave you with totally blank internal storage. You'll have to flash a ROM from an external SD, or load a ROM zip over USB while booted in recovery because internal storage will be wiped clean.
It might be a good idea to look into what bootloader and modem you're running too. If you're still using CWM, you might be on pretty old firmware that isn't going to work right with newer roms. Just don't start flashing bootloaders/modems willy-nilly. Samsung made this phone kind of easy to hard brick on the newer firmwares. There's a right way to update it, if you find you have to.
Click to expand...
Click to collapse
Thanks so much for providing such a detailed answer!! You make many very good points!!
Just to reflect on those...
1) Yes, CWM recovery has not been updated for about 2-3 years. I have 6.0.4.7 version. Where do I check how stale it really is? I tried googling for CWM recovery and saw tons of links with everyone talking about CWM but ZERO sites with actual CWM .zip or .img file
2) I did 'adb bugreport' and was able to find information on my bootloader and a modem:
Bootloader: I747UCUEMJB
Radio: I747UCUEMJB
I am not too sure for what I would need to use this information for though
3) when completely blanking the phone (doing all those wipe/erase actions you mentioned), would that erase the recovery as well or is recovery is kept on a some other partition that never gets touched
4) When installing TWRP over CWM, would TWRP override CWM or install side to side along with CWM?
Thanks!

The will need to run an updated bootloader and modem before installing the latest custom roms.

user-747 said:
2) I did 'adb bugreport' and was able to find information on my bootloader and a modem:
Bootloader: I747UCUEMJB
Radio: I747UCUEMJB
I am not too sure for what I would need to use this information for though
3) when completely blanking the phone (doing all those wipe/erase actions you mentioned), would that erase the recovery as well or is recovery is kept on a some other partition that never gets touched
4) When installing TWRP over CWM, would TWRP override CWM or install side to side along with CWM?
Thanks!
Click to expand...
Click to collapse
3 - Those wipes will just blank /system, /data and other partitions that would affect a rom. More critical areas like bootloader, modem, and recovery will remain untouched and intact.
4 - TWRP will overwrite CWM in the /recovery partition. They can't coexist.
2 - If you're comfortable with Odin, this thread might be the easiest and safest way to get updated. The Odin tar will get you up to NE4 firmware that should work with all the newest roms. Before modding, you could check for updates a few times in that stock rom. There should be two, one from NE4 to NJ1, and one NJ1 to NJ2. NJ2 is the newest and almost certainly last update for the i747.
If you don't like using Odin, there are recovery flashable zips to update the firmware for i747 too. You just have to be very careful how you go about it or you can brick the phone.

audit13 said:
The will need to run an updated bootloader and modem before installing the latest custom roms.
Click to expand...
Click to collapse
I was able to install the most recent octos just a few days ago with my stale configuration: old bootloader and old cwm recovery. My phone i747 currently has nougat.
When you speak of 'latest roms' what exactly do you have in mind?

jason2678 said:
3 - Those wipes will just blank /system, /data and other partitions that would affect a rom. More critical areas like bootloader, modem, and recovery will remain untouched and intact.
4 - TWRP will overwrite CWM in the /recovery partition. They can't coexist.
2 - If you're comfortable with Odin, this thread might be the easiest and safest way to get updated. The Odin tar will get you up to NE4 firmware that should work with all the newest roms. Before modding, you could check for updates a few times in that stock rom. There should be two, one from NE4 to NJ1, and one NJ1 to NJ2. NJ2 is the newest and almost certainly last update for the i747.
If you don't like using Odin, there are recovery flashable zips to update the firmware for i747 too. You just have to be very careful how you go about it or you can brick the phone.
Click to expand...
Click to collapse
I am actually quite familiar with Odin. I used to root i747 with it. Then I wanted to update to the latest official rom and ironically soft-bricked the phone to the point where it was dead...nothing worked at all. If I remember correctly I wrote i9305 Rom to i747 phone. Then I found out that during boot the phone internally still scans through sd card and was able to take advantage of that to install recovery and consequently cyanogenmod os. I remember tons of Adb done. Since then the phone regained all functionality and now works very smooth with freshly installed octos. However, I see I am missing some hard drive space ie unusually large usage by octos. This makes me wonder if the 'bad original partition + bootloader +modem' are still in there but not invoked for some reason and the explanation behind my what appears to be successful installs is working os, etc are written to a separate partition which is now invoked. Is this hypothesis legit or not real? Is it at all possible that my cwm somehow is installed on a partition that is delete-able or that cannot be a possibility and all recovery goes into write-protected space?
And while we are in this topic, what are the obvious advantages of a newer boot loader if I can still install whatever custom roms?

user-747 said:
I was able to install the most recent octos just a few days ago with my stale configuration: old bootloader and old cwm recovery. My phone i747 currently has nougat.
When you speak of 'latest roms' what exactly do you have in mind?
Click to expand...
Click to collapse
Sometimes, a phone will not display the correct imei with the latest custom ROM unless the phone is running the most recent bootloader and modem for the particular phone.

audit13 said:
Sometimes, a phone will not display the correct imei with the latest custom ROM unless the phone is running the most recent bootloader and modem for the particular phone.
Click to expand...
Click to collapse
Thanks! Good to know.

I think this phone only has a 12 GB data partition. About 1.5 GB is reserved for /system, another 1 GB for /cache, and there are a host of other partitions. That's some of your used space. The rest could be cruft from old installs left over in userdata that a standard wipe of /data didn't get unless you format internal storage.
If what you have is working for you, then I wouldn't touch bootloader and modem.

jason2678 said:
You should really flash TWRP recovery before proceeding. CWM hasn't been maintained or updated in a long time. It is likely to give you problems flashing anything new.
To completely blank a phone in TWRP I use Wipe -> Advanced Wipe -> Dalvik, Cache, System, Data. Followed by Wipe -> Format Data then type "yes" to confirm; always a good idea if you're switching between Touchwiz and AOSP in particular. That will leave you with totally blank internal storage. You'll have to flash a ROM from an external SD, or load a ROM zip over USB while booted in recovery because internal storage will be wiped clean.
It might be a good idea to look into what bootloader and modem you're running too. If you're still using CWM, you might be on pretty old firmware that isn't going to work right with newer roms. Just don't start flashing bootloaders/modems willy-nilly. Samsung made this phone kind of easy to hard brick on the newer firmwares. There's a right way to update it, if you find you have to.
Click to expand...
Click to collapse
jason2678 said:
I think this phone only has a 12 GB data partition. About 1.5 GB is reserved for /system, another 1 GB for /cache, and there are a host of other partitions. That's some of your used space. The rest could be cruft from old installs left over in userdata that a standard wipe of /data didn't get unless you format internal storage.
If what you have is working for you, then I wouldn't touch bootloader and modem.
Click to expand...
Click to collapse
Thanks for the insight!
I went ahead and updated by recovery to TWRP via Odin just a few minutes ago...
I see Under Advanced Wipe another option for Wipe -> Advanced Wipe -> Internal Storage. Should I also wipe out internal storage? What is it for anyway? Whats the difference between 'internal storage' and 'system'?

user-747 said:
Thanks for the insight!
I went ahead and updated by recovery to TWRP via Odin just a few minutes ago...
I see Under Advanced Wipe another option for Wipe -> Advanced Wipe -> Internal Storage. Should I also wipe out internal storage? What is it for anyway? Whats the difference between 'internal storage' and 'system'?
Click to expand...
Click to collapse
Honestly I'm not 100% sure what the Internal Storage wipe does under Advanced Wipe, and I don't feel like making then restoring a backup right now just to test it . I never use it. If I had to guess, I bet it wipes /data and possibly a few other partitions without preserving user files in /data/media/0, see below, but don't know that. It certainly won't blank the whole internal storage; some areas like recovery, modem, and aboot are far too important and won't be touched.
Here's what I can tell you. Doing Wipe -> Advanced Wipe -> system, data, cache, dalvik is typically good enough for flashing a new rom (switching from Touchwiz to AOSP can require some additional care), some would even say overkill the way rom installers are scripted today, but old habits die hard. However, Advanced Wipe -> Data will wipe /data without wiping /data/media. Since android got multi-user support, files reported to be in /sdcard are actually stored in /data/media/0 for the primary user, so that means that downloads, pictures, user app files and things like that can be left behind by just wiping data since /data/media is left untouched. It is useful if you don't want to shuffle your files off then back on the device to flash something new or if you're using a device without an external SD and have a rom zip stored on device in /sdcard, but it leaves stuff behind if you're looking for a clean start.
To completely blank /data pick Wipe -> Format Data and TWRP will format /data and leave nothing behind, not even /data/media like the normal Advanced Wipe -> Data preserves. Just make sure you're prepared for the phone storage to be blank. You'll have to flash from external SD or push files from a computer over usb. TWRP does automatically start up mtp and adb shortly after booting if you need to push files over usb.
/system is a partition of special reserved space just for the rom and system apps and not user files. It is usually mounted read only when booted up normally to keep us from messing anything important up. I hope this helps and doesn't just muddy the waters more.

jason2678 said:
Honestly I'm not 100% sure what the Internal Storage wipe does under Advanced Wipe, and I don't feel like making then restoring a backup right now just to test it . I never use it. If I had to guess, I bet it wipes /data and possibly a few other partitions without preserving user files in /data/media/0, see below, but don't know that. It certainly won't blank the whole internal storage; some areas like recovery, modem, and aboot are far too important and won't be touched.
Here's what I can tell you. Doing Wipe -> Advanced Wipe -> system, data, cache, dalvik is typically good enough for flashing a new rom (switching from Touchwiz to AOSP can require some additional care), some would even say overkill the way rom installers are scripted today, but old habits die hard. However, Advanced Wipe -> Data will wipe /data without wiping /data/media. Since android got multi-user support, files reported to be in /sdcard are actually stored in /data/media/0 for the primary user, so that means that downloads, pictures, user app files and things like that can be left behind by just wiping data since /data/media is left untouched. It is useful if you don't want to shuffle your files off then back on the device to flash something new or if you're using a device without an external SD and have a rom zip stored on device in /sdcard, but it leaves stuff behind if you're looking for a clean start.
To completely blank /data pick Wipe -> Format Data and TWRP will format /data and leave nothing behind, not even /data/media like the normal Advanced Wipe -> Data preserves. Just make sure you're prepared for the phone storage to be blank. You'll have to flash from external SD or push files from a computer over usb. TWRP does automatically start up mtp and adb shortly after booting if you need to push files over usb.
/system is a partition of special reserved space just for the rom and system apps and not user files. It is usually mounted read only when booted up normally to keep us from messing anything important up. I hope this helps and doesn't just muddy the waters more.
Click to expand...
Click to collapse
Thanks!
I will try to do wipe and reinstall Rom tonight and will update this thread. While we are in this topic, when flashing twrp via Odin in phone's download mode, I noticed that it says: Qualcomm secureboot: enabled. Does this mean my bootloader is locked?

user-747 said:
Thanks!
I will try to do wipe and reinstall Rom tonight and will update this thread. While we are in this topic, when flashing twrp via Odin in phone's download mode, I noticed that it says: Qualcomm secureboot: enabled. Does this mean my bootloader is locked?
Click to expand...
Click to collapse
No, the i747 never had a locked bootloader. You couldn't boot unsigned stuff like CWM, TWRP, or octos if it did.

jason2678 said:
No, the i747 never had a locked bootloader. You couldn't boot unsigned stuff like CWM, TWRP, or octos if it did.
Click to expand...
Click to collapse
Thanks!

user-747 said:
Thanks!
I will try to do wipe and reinstall Rom tonight and will update this thread. While we are in this topic, when flashing twrp via Odin in phone's download mode, I noticed that it says: Qualcomm secureboot: enabled. Does this mean my bootloader is locked?
Click to expand...
Click to collapse
I went ahead and did all the wipes and formats you recommend and all worked like a charm. OctOs installed like a charm, my disk space is regained, gapps are working, IMEI is good. so far I cannt find anyting that does not work. Thank you @jason2678 for your valuable feedback on my questions!!

[SOLVED] How to completely wipe literally EVERYTHING

I looked through many threads, posts, websites, and tutorials, but none of them say how to literally wipe my device completely (it could be that it's not possible), what I want to do is completely remove literally everything so that it's like a brand new hard drive without even any files in it.
'Factory Reset' doesn't remove everything because android still boots after a factory reset and android wouldn't be able to boot if there were no files on the device. TWRP doesn't remove everything either because how is twrp running, and I can still see the androids root directories in twrps file manager (TWRP does tell me that there's no OS installed, but then why is there still a functioning file system with actual files in them).
I want to completely wipe everything so that any future roms I download will have no way to be affected by any old kernels/roms/apps that I have installed in the past. I want to clean install android on top of a literally empty phone hard drive. If this isn't possible then what's the closest to that that I can get? Cuz I tried various roms and I had bugs that persisted between multiple roms even though other people said that they didn't have these issues.
In case you're wondering: I'm currently running LineageOS 15.1, oreo 8.1

Your best bet it to wipe using stock image. Reinstall TWRP and wipe system, cache and data before installing new ROM

I agree with the advice given by Vanschtezla.
Also, if you would completely wipe all data on the phone's storage then that would also wipe the partition table. The storage area is divided into partitions which are mounted to for example /system /data and /cache when your phone boots.
Also there is no real need to "wipe everything" as you say as that could brick your phone. If you just boot TWRP and wipe using "Factory reset" and additionally: System then everything should be clean enough to install a new ROM. Depending on the ROM it will wipe the System partition anyway.
Kernels reside in the system partition so when you wipe System, any Kernel is gone
Pre installed (system) Apps sit in the System partition so wipe System and they are gone
User Apps sit in the data partition so wipe data (that is included in the Factory reset) and they're gone
All in all I think you're expecting issues that simply do not exist. Especially if you just follow the instructions of the (custom) ROM you want to install.

THANK YOU!
peterpv said:
I agree with the advice given by Vanschtezla.
Kernels reside in the system partition so when you wipe System, any Kernel is gone
Pre installed (system) Apps sit in the System partition so wipe System and they are gone
User Apps sit in the data partition so wipe data (that is included in the Factory reset) and they're gone
Click to expand...
Click to collapse
This is exactly what I was looking for! Why don't any "How to wipe your phone" guides say these things (even the ones that get more technical don't mention what exactly gets deleted for each wipe option, which is why from your perspective it was probably very weird to read my question).