HELP!!! How to fix "Can’t load Android System your data may be corrupt" error without losing your data ?

[aIecxs]

okay, maybe I gave bad advice. you can add your own block of code, but do not add lines in other blocks (for now). as you can clearly see line 17 - 33 is one code block

 

[optimusodd]

okay, maybe I gave bad advice. you can add your own block of code, but do not add lines in other blocks (for now). as you can clearly see line 17 - 33 is one code block

I re-edited it.Is it okay now ?
I hope 2 seperate blocks starting with the same code on early-init won't create any conflict.

 

[aIecxs]

yes, that's fine. the on condition can exist multiple times. we might change it to late-init later..

 

[optimusodd]

_________________________________

 

[optimusodd]

you could try to get dmesg as early as possible, but there is nothing mounted so no idea where to save log. lets try cache partition. you need to pack some files in boot ramdisk
https://topjohnwu.github.io/Magisk/guides.html#root-directory-overlay-system
myscript.sh

#!/system/bin/sh
/system/bin/dmesg -w >> /cache/recovery/dmesg.log

(magisk patched boot.img required for overlay.d

or
modify init.rc directly, place myscript somewhere else and hardcode path)

on early-init
    start myservice

service myservice /sbin/myscript.sh
    oneshot

edit: both is needed, any .rc file and any .sh file, which then execute dmesg (it's like logcat) I hope it's not too confusing.

Still getting same boot-loop

 

[aIecxs]

yes, of course you get same boot-loop. this modification is intended to write dmesg log to cache partition, not to fix boot-loop

 

[optimusodd]

next you can get a copy of cache.bin and loop mount (you have done it before). if you find

yes, of course you get same boot-loop. this modification is intended to write dmesg log to cache partition,

In case you bricked just restore backup boot.img and go for logs in cache partition. loop mount the partition image

mkdir ~/cache
sudo -H mount -t ext4 -o loop,ro,noexec,noload,noatime ./cache.img ~/cache
sudo -H thunar ~/cache

Restored boot.bin and ran the commands given above.
Here is the outcome.

 

[aIecxs]

failed to setup loop device - try to setup manually, then mount the loop device. it's purely linux error shoud not happen. for /dev/loop? insert the correct loop device displayed in the previous command.
(use prefix sudo for running commands with root privileges)

losetup -vf cache.img
losetup -a
mount -t ext4 -vo loop,ro,noexec,noload,noatime /dev/loop? ~/cache

 

[optimusodd]

failed to setup loop device - try to setup manually, then mount the loop device. it's purely linux error shoud not happen. for /dev/loop? insert the correct loop device displayed in the previous command.
(use prefix sudo for running commands with root privileges)

losetup -vf cache.img
losetup -a
mount -t ext4 -vo loop,ro,noexec,noload,noatime /dev/loop? ~/cache

"Setup manually ? Mount the loop device ? Insert the correct loop device? " I am sorry, didn't get even a single thing.I am a complete novice in the field of Linux and don't understand the terms being used.I love learning new stuff and I have learnt a lot in past few months.Though I adapt quickly ,at this point of time I am occupied with so many things and unable to give my time and focus to learn Linux stuff.It has already been 6 months and I desperately need to retireve my data.I am starting to lose hope.

Am I supposed to run given commands ? If yes.again "use prefix sudo for running commands with root privileges".How would we know which command to be run with sudo ?

Can you please give straight forward instructions to be followed, like, run this command or edit that file ? I am not asking for spoon feeding,I don't like it.I am just requesting for step by step instructions as that will save a lot of confusion and time.Your understanding and patience is greatly appreciated!! Thank you!

 

[aIecxs]

what's the output of losetup please?

cd ~/Desktop
sudo losetup -vf cache.bin
losetup -a

 

[optimusodd]

what's the output of losetup please?

cd ~/Desktop
sudo losetup -vf cache.bin
losetup -a

Here is the output.

 

[aIecxs]

do you have cache.bin on your desktop? after myscript.sh was executed from myservice (modified init.rc) you must dump cache partition off device again, as this is the target where the dmesg log is suppposed to saved from myscript.sh

~/Desktop is from your screenshot post #67, if the file is somewhere else cd into correct directory.

 

[optimusodd]

do you have cache.bin on your desktop?

There is no cache folder on Desktop.
There is a cache folder on Home and that folder is empty.

 

[aIecxs]

I don't know how your files are organized. have a look into /media/optimus/01D82E33678EEF20 maybe. it's your computer

 

[optimusodd]

after myscript.sh was executed from myservice (modified init.rc) you must dump cache partition off device again, as this is the target where the dmesg log is suppposed to saved from myscript.sh

Hello, I ran ./edl.py r cache cache.img and that dumped cache.img inside edl folder.
Then I moved cache.img to Desktopand ran following commands

mkdir ~/cache
sudo -H mount -t ext4 -o loop,ro,noexec,noload,noatime ./cache.img ~/cache
sudo -H thunar ~/cache

It displayed 5 folders in /home/optimus/cache/.

Is it done correctly ? What are we supposed to do now ? Thank you!

One thing I failed to understand that when I used 7 zip to open same cache.img on Windows,it displayed 7 folders.


One more thing,it's not letting me move recovery folder or create an archive.

 

[aIecxs]

yes done correctly. maybe enable View - Show Hidden Files will show all 7 directories.

creating dmesg.log was not successful, there is no such file. maybe insufficient permissions.

I don't have a device to test so this is just guesswork.. try again with more settings. (the goal is to execute myscript.sh successfully)

on early-init
    start myservice

service myservice /sbin/myscript.sh
    seclabel u:r:init:s0
    user root
    group root
    oneshot
    disabled

I am not quite sure its even possible to run anything under u:r:init:s0 secontext on your android version, so if you patch boot.img with Magisk you can use above code with u:r:magisk:s0 instead.

on early-init
    start myservice

service myservice /sbin/myscript.sh
    seclabel u:r:magisk:s0
    user root
    group root
    oneshot
    disabled

 

[optimusodd]

Are you really hopeful that we can make it and retrieve the data or am I on a wild goose chase ?

 

[aIecxs]

"any way to get logcat with bootloader locked and usb debugging disabled ?"

this is what it's about, right? the easy part, trying to get logs...

if you want forecast to data recovery, follow the white rabbit
https://forum.xda-developers.com/t/...sue-after-rom-downgrade.4168821/post-85195483

 

[optimusodd]

maybe enable View - Show Hidden Files will show all 7 directories.creating dmesg.log was not successful, there is no such file.

Recovery files I shared were extracted on Windows.How do you obtain these files on Linux where it doesn't let you move recovery folder or create an archive citing you don't have the right permissions ?

 

[aIecxs]

you have mounted cache.img read-only so you can read files but you cannot create files inside cache. you can copy recovery or create archive to other location