Database Develop

Flashing Issues/Permission Issues

A few days ago I got my Atrix HD and immediately rooted and subsequently unlocked the bootloader. Later I successfully flashed EcHoFiiVe's paranoidAndroid port... I didn't really like it because of the aspect ratio (too tiny) so I tried to flash back to a stock ROM. I lost and later accidentally deleted the backup I had made of the stock ROM that came on the device so that is now out of the question but for some reason, no matter what I do, I can't make changes to /system from the recovery or from the bootloader using fastboot commands. I've tried inputing
Code:
fastboot erase system -w
and it told me that I didn't have sufficient permissions and that the command failed. Therein lies my problem. Fortunately, I have a runnable backup (PA) I just really wish to try something different and the device is adamantly against the idea. According to the bootloader the device is unlocked with status code 3. Any help will be greatly appreciated!

read this
http://forum.xda-developers.com/showthread.php?t=2226527

frog1982 said:
read this
http://forum.xda-developers.com/showthread.php?t=2226527
Click to expand...
Click to collapse
I've read through that and I can now see a line that I missed that said that it was a common issue for that particular command to not work but I still don't know what to do about my inability to flash a different ROM. I have tried to mount /system before flashing and I've tried wiping /system using the recovery before flashing, all without avail. Do you have any advice on how to wipe the system partition?

you do not have to wipe it just fastboot flash Mex retail to overwrite it and you will be starting over.

frog1982 said:
you do not have to wipe it just fastboot flash Mex retail to overwrite it and you will be starting over.
Click to expand...
Click to collapse
to be clear, are you saying I can just do this:
Extract the zip
Open a terminal to the extracted zips directory
Reboot into fastboot
Type the following commands in this order
Code:
fastboot flash boot boot.img
fastboot flash devtree device_tree.bin
fastboot flash system system.img
fastboot -w
fastboot reboot

sparkplugDev said:
to be clear, are you saying I can just do this:
Extract the zip
Open a terminal to the extracted zips directory
Reboot into fastboot
Type the following commands in this order
Code:
fastboot flash boot boot.img
fastboot flash devtree device_tree.bin
fastboot flash system system.img
fastboot -w
fastboot reboot
Click to expand...
Click to collapse
yes but make sure you also have the snap-fastboot files in the folder you are working in or in your path

[No More Errors] [Fastboot Rom Flashing] [Direct Method]

Hi all,
Yesterday i flashed miui LP on my Redmi 2 Prime. In the evening i tried to flash the miui KK with fastboot rom. But ended up with unspecified error . I tried many things but no luck. Then i followed direct method and that worked. Following is the procedure.
Note:
1. This will erase all your data and internal storage so better you backup them first.
2. I'm not responsible if anything goes wrong with your device.
Requirement:
1. Minimal ADB and Fastboot
2. Fastboot rom
3. Mi Pc Suite (for drivers, you can skip if already installed drivers)
Preparing:
1. Install Mi Pc Suite.
2. Install Minimal ADB and Fastboot.
3. Extract fastboot rom anywhere.
4. Copy all the files from images folder to the directory where Minimal ADB And fastboot is installed.
for example C:\Program Files (x86)\Minimal ADB and Fastboot
Procedure:
1. Connect your phone to pc in fastboot mode,
your Pc will install some drivers automatically.
2. Go to Minimal ADB and Fastboot directory .
3. Hold shift and right click.
4. Click open command window here.
5. Enter fastboot devices command.
If you see your device name in list of devices attached in command window then your good to go.
6. Now enter the following commands given below one by one in sequence.
fastboot flash partition gpt_both0.bin
fastboot flash tz tz.mbn
fastboot flash sbl1 sbl1.mbn
fastboot flash rpm rpm.mbn
fastboot flash aboot emmc_appsboot.mbn
fastboot flash hyp hyp.mbn
fastboot flash tzbak tz.mbn
fastboot flash sbl1bak sbl1.mbn
fastboot flash rpmbak rpm.mbn
fastboot flash abootbak emmc_appsboot.mbn
fastboot flash hypbak hyp.mbn
fastboot erase boot
fastboot flash modem NON-HLOS.bin
fastboot flash system system.img
fastboot flash cache cache.img
fastboot flash userdata userdata.img
fastboot flash recovery recovery.img
fastboot flash boot boot.img
fastboot flash persist persist.img
fastboot flash sec sec.dat
fastboot flash splash splash.img
fastboot reboot
Or
Simply put Flash All.bat (Attached Bellow) in Minimal ADB and Fastboot directory and double click on it (No need to enter those commands). Your Devices will reboot automatically when flashing done.
congrats
Hit thanks

It fails at the first step. Can't flash the partition table, it always says "FAILED (remote: failed to write partition)"
I've tried several different ROM packs, even tried one for a different Redmi 2 version, and still can't do it.

did you place all the files in minimal adb and fastboot folder?
gabika1941 said:
It fails at the first step. Can't flash the partition table, it always says "FAILED (remote: failed to write partition)"
I've tried several different ROM packs, even tried one for a different Redmi 2 version, and still can't do it.
Click to expand...
Click to collapse
did you place all the files in minimal adb and fastboot folder? And what you mean by using several different rom package? This method is only for fastboot rom made for redmi 2 only. Make sure your phone is detected by PC in fastboot mode with command fastboot devices.
I have tested this method three times without any errors. You are surely doing something wrong.

screenshot
gabika1941 said:
It fails at the first step. Can't flash the partition table, it always says "FAILED (remote: failed to write partition)"
I've tried several different ROM packs, even tried one for a different Redmi 2 version, and still can't do it.
Click to expand...
Click to collapse
Can you attach a screenshot of your minimal adb and fastboot folder here. Also attach screenshot of your cmd window when you face error.

rkmadotra said:
Can you attach a screenshot of your minimal adb and fastboot folder here. Also attach screenshot of your cmd window when you face error.
Click to expand...
Click to collapse
i have a similar problem :
C:\Xiaomi\wt86047_pro_images_6.3.25_20160307.0000.16_5.1_cn_ee14351bfb\images>fastboot.exe flash partition gpt_backup0.bin
target reported max download size of 268435456 bytes
sending 'partition' (16 KB)...
OKAY [ 0.005s]
writing 'partition'...
FAILED (remote: failed to write partition)
finished. total time: 0.018s
C:\Xiaomi\wt86047_pro_images_6.3.25_20160307.0000.16_5.1_cn_ee14351bfb\images>
Click to expand...
Click to collapse
I have a 2014813 , was using a moded 2014811 rom on it. Kept crashing wanted to reflash , and installed TWRP on it , that said can't mount partitions and now i can't flash neider the 811 or the 813 roms to it . Just keeps saying error writing to partition . I can attach a screenshot of the Miflash tool if it helps. And above is the Command prompt error.

Pushing just 5 img files didn't worked for me and was stuck on MI logo, but pushing all files was reviving my phone!
Thank you very much for this method!

sir, my Redmi 2 is bricked
when I am trying to flash this the error messages is coming like
cannot load " gpt_both0.bin".
like these and so on. when I am using flash all.bat same messages is coming and then after erasing boot the phone reboots with black screen .
sir please help me
your help will be highly appriciated.
[email protected]

My phone stucks on Mi logo what will do

yeah!!!!!!!!!!!! after trying many other methods like recovery through adb ,command prompt,mi flash tool,mi pc suit...... i downloaded atleast 4-5 roms to just confirm that whether flash tool has some problem or the ROMs..........but if something worked after constantly trying many things in past three days it is this method.......seriously...
FYI this is the way i used it and u should probably use the same way
-> download MI flash tool (google it)
->install(in C
->download any compatible ROM for ur phone
->open :- C:\Program Files\Xiaomi\MiPhone\Google\Android
->paste all the contents of image folder from the ROM into this android folder
->then download this Flash All.bat from here and extract it...
->put your phone in fastboot mode ->connect it via usb
->then double click your Flash all.bat file-> give it some time->once finished ur device will start automatically
->after 10 mins or so disconnect ur phone from pc ... give it 4-5 mins , ur phone will be out of bootloop and u will be awarded with a new MIUI

Yes! It worked for me as well.
Thanks for your steps.
(FYI this is the way i used it and u should probably use the same way
-> download MI flash tool (google it)
->install(in C
->download any compatible ROM for ur phone
->open :- C:\Program Files\Xiaomi\MiPhone\Google\Android
->paste all the contents of image folder from the ROM into this android folder
->then download this Flash All.bat from here and extract it...
->put your phone in fastboot mode ->connect it via usb
->then double click your Flash all.bat file-> give it some time->once finished ur device will start automatically
->after 10 mins or so disconnect ur phone from pc ... give it 4-5 mins , ur phone will be out of bootloop and u will be awarded with a new MIUI )
and it worked good.
My Mi Account was locked and could not connect to internet at all.
I had tried using Flash tools, PC suite - Flash methods and nothing worked. I had spend more time to fix my mobile in all these ways.
But this method is awesome. Only took around 15 minutes to completely flash my mobile.
After flashing the mobile, I am able to connect to internet and I have also created a new Mi-Account and linked my G-Mail account to it.
Am super happy now.
Thanks a lot.
However I would wish to add another details to the above setps:
The Flashall.BAT too needs to be extracted and copied into the same folder where the contents from ROM's Image folder were copied.

awesome bro thankyou very much.it's working absolutely well:good::good:

Tried a similar method and got my redmi2 prime hard bricked. Can someone tell me the test points in the device 2014818?

Thanx This works for me. successfull to flash my redme 2
Simply put Flash All.bat (Attached Bellow) in Minimal ADB and Fastboot directory and double click on it (No need to enter those commands). Your Devices will reboot automatically when flashing done.
congrats
Hit thanks[/QUOTE]

Will this work for Redmi note 3 Snapdragon??

Hello
I am stick in bootloop with my Redmi 3 (after trying Flashify).
Tried the above method with high hopes, as I have been trying everything else also with no luck.
I have downloaded a ROM for my device of course.
It all seems to go well until I launch the Flash_All.bat
Then the DOS commands are executed in 5 to 10 secs, and my devices reboot, but in a bootloop again
I got a breif view at the DOS commands, and it basically, at several lines says somthing, like: "failed to write, device is locked"
see attached sreen shot
does this mean my problem has no solution and I can simply throw away my device?
Thanks

rkmadotra said:
Hi all,
Yesterday i flashed miui LP on my Redmi 2 Prime. In the evening i tried to flash the miui KK with fastboot rom. But ended up with unspecified error . I tried many things but no luck. Then i followed direct method and that worked. Following is the procedure...
Click to expand...
Click to collapse
You solved my problem :good:

Thank you buddy..... This method works

Fastbooting method did not bring back my stock model number that is hm2014818. It changed to 2014817 when i flashed miui 8 64bit rom for redmi 2. Now i am not able to go back to my original model number even by fastboot method. Any help please??

will the flash all.bat support on other mi device's??

stuck at erasing user data
flashing stuck at flashing userdata

[GUIDE] Unlock bootloader on 8.1

As you know, on 8.1 we still have ununlockable bootloader. But it's quite simple to fix, just flash 'old' bootloader
It's unofficial method
1) Go to fastboot bode (keep + button on reboot/boot your phone)
2) Use service firmware or download this https://vk.com/doc275347426_479517439 , open command promp (start.bat)
3) VERY IMPORTANT
you should know your platfotm. As I know, 2 GB (my phone) have 8917 processor, 3gb/32 have 8937. You can get your platform with this
Code:
fastboot getvar platform
4) I have 8917, so I type
Code:
fastboot flash aboot 8917_emmc_appsboot.mbn
fastboot flash abootbak 8917_emmc_appsboot.mbn
On 8937 type
Code:
fastboot flash aboot 8937_emmc_appsboot.mbn
fastboot flash abootbak 8937_emmc_appsboot.mbn
5) Reboot your phone, you should get 'device state unlocked' , if not, do like U did this on old bootloader from fastboot
6)Flash twrp as usual. In archive I already include this, you can flash it with
Code:
fastboot flash recovery twrp.img
And install magisk/SSu
Attention: if you wanna get full access for /data partition from twrp, you should flash patch with prevent autoencrypt. I did not do this, system access is enought for me.
But before you root your device, U have to erase data partition, coz root patch boot partition too, patched boot can not load stocky encrypted data. After data format you can flash magisk. When you boot phone, it will encrypt data partition and you get installed Magisk and ecrypted data
Original system/boot images, restore them with twrp https://mega.nz/#!ziJxCCqA!C0lG5hUcOGwl2ER0Mp342lfx5_DOIzalAi7RExR6nro

My phone is 8937 and device state remains locked after stage 5. And "if not, do like U did this on old bootloader from fastboot" means we should use some other adb codes? Such as?
Woohooo, the display has been turned upside down. How do I fix this?
---------- Post added at 03:24 PM ---------- Previous post was at 03:17 PM ----------
What the ??? Stock recovery is upside down, but fastboot is the right way. Is this supposed to happen?
---------- Post added at 03:45 PM ---------- Previous post was at 03:24 PM ----------
Hmmm, I think I'll pass on this method. I appreciate the effort, but too much weirdness happening with my phone.

igerup said:
My phone is 8937 and device state remains locked after stage 5. And "if not, do like U did this on old bootloader from fastboot" means we should use some other adb codes? Such as?
Woohooo, the display has been turned upside down. How do I fix this?
---------- Post added at 03:24 PM ---------- Previous post was at 03:17 PM ----------
What the ??? Stock recovery is upside down, but fastboot is the right way. Is this supposed to happen?
Click to expand...
Click to collapse
worked thanks

Display rotates only few seconds when it boot

Dreamject said:
Display rotates only few seconds when it boot
Click to expand...
Click to collapse
It doesn't bother me at all ? it worked perfectly, thanks for your work

Dreamject said:
As you know, on 8.1 we still have ununlockable bootloader. But it's quite simple to fix, just flash 'old' bootloader
It's unofficial method
1) Go to fastboot bode (keep + button on reboot/boot your phone)
2) Use service firmware or download this https://vk.com/doc275347426_479517439 , open command promp (start.bat)
3) VERY IMPORTANT
you should know your platfotm. As I know, 2 GB (my phone) have 8917 processor, 3gb/32 have 8937. You can get your platform with this
Code:
fastboot getvar platform
4) I have 8917, so I type
Code:
fastboot flash aboot 8917_emmc_appsboot.mbn
fastboot flash abootbak 8917_emmc_appsboot.mbn
On 8937 type
Code:
fastboot flash aboot 8937_emmc_appsboot.mbn
fastboot flash abootbak 8937_emmc_appsboot.mbn
5) Reboot your phone, you should get 'device state unlocked' , if not, do like U did this on old bootloader from fastboot
6)Flash twrp as usual. In archive I already include this, you can flash it with
Code:
fastboot flash recovery twrp.img
And install magisk/SSu
Attention: if you wanna get full access for /data partition from twrp, you should flash patch with prevent autoencrypt. I did not do this, system access is enought for me.
But before you root your device, U have to erase data partition, coz root patch boot partition too, patched boot can not load stocky encrypted data. After data format you can flash magisk. When you boot phone, it will encrypt data partition and you get installed Magisk and ecrypted data
Original system/boot images, restore them with twrp https://mega.nz/#!ziJxCCqA!C0lG5hUcOGwl2ER0Mp342lfx5_DOIzalAi7RExR6nro
Click to expand...
Click to collapse
dont work for me, than i do this:
1. do what you told
2. use unlock bootloader from asus website
3. repeat what you told
4. walaaa... my device unlocked, than i flash twrp and magisk
5. done, i have rooted device
:laugh::laugh::laugh:
thank you guys...

no no no ..... not work for me, and upside down the title!!!!!
I have no choice but to fix it with: xxx youtube................. /watch?v=s592QY56VjM
than restore back to oreo 8.1..........

tfstk said:
no no no ..... not work for me, and upside down the title!!!!!
I have no choice but to fix it with: xxx youtube................. /watch?v=s592QY56VjM
than restore back to oreo 8.1..........
Click to expand...
Click to collapse
if you screen rotated on thethe boot, it means you have old bl. You just needneed toto flashflash twrp, or unlock bl with fastboot

Dreamject said:
As you know, on 8.1 we still have ununlockable bootloader. But it's quite simple to fix, just flash 'old' bootloader
It's unofficial method
1) Go to fastboot bode (keep + button on reboot/boot your phone)
2) Use service firmware or download this https://vk.com/doc275347426_479517439 , open command promp (start.bat)
3) VERY IMPORTANT
you should know your platfotm. As I know, 2 GB (my phone) have 8917 processor, 3gb/32 have 8937. You can get your platform with this
Code:
fastboot getvar platform
4) I have 8917, so I type
Code:
fastboot flash aboot 8917_emmc_appsboot.mbn
fastboot flash abootbak 8917_emmc_appsboot.mbn
On 8937 type
Code:
fastboot flash aboot 8937_emmc_appsboot.mbn
fastboot flash abootbak 8937_emmc_appsboot.mbn
5) Reboot your phone, you should get 'device state unlocked' , if not, do like U did this on old bootloader from fastboot
6)Flash twrp as usual. In archive I already include this, you can flash it with
Code:
fastboot flash recovery twrp.img
And install magisk/SSu
Attention: if you wanna get full access for /data partition from twrp, you should flash patch with prevent autoencrypt. I did not do this, system access is enought for me.
But before you root your device, U have to erase data partition, coz root patch boot partition too, patched boot can not load stocky encrypted data. After data format you can flash magisk. When you boot phone, it will encrypt data partition and you get installed Magisk and ecrypted data
Original system/boot images, restore them with twrp https://mega.nz/#!ziJxCCqA!C0lG5hUcOGwl2ER0Mp342lfx5_DOIzalAi7RExR6nro
Click to expand...
Click to collapse
I've problem that if I mounted System partition in Any App,it will freeze my Systemui and can't do anything
Since 7.1.1 to 8.1 still have these problem

tony8077616 said:
I've problem that if I mounted System partition in Any App,it will freeze my Systemui and can't do anything
Since 7.1.1 to 8.1 still have these problem
Click to expand...
Click to collapse
DonT know.... Try magiskmagisk, system less stuff, change launcher, disable bloatware

Dreamject said:
As you know, on 8.1 we still have ununlockable bootloader. But it's quite simple to fix, just flash 'old' bootloader
It's unofficial method
1) Go to fastboot bode (keep + button on reboot/boot your phone)
2) Use service firmware or download this https://vk.com/doc275347426_479517439 , open command promp (start.bat)
3) VERY IMPORTANT
you should know your platfotm. As I know, 2 GB (my phone) have 8917 processor, 3gb/32 have 8937. You can get your platform with this
Code:
fastboot getvar platform
4) I have 8917, so I type
Code:
fastboot flash aboot 8917_emmc_appsboot.mbn
fastboot flash abootbak 8917_emmc_appsboot.mbn
On 8937 type
Code:
fastboot flash aboot 8937_emmc_appsboot.mbn
fastboot flash abootbak 8937_emmc_appsboot.mbn
5) Reboot your phone, you should get 'device state unlocked' , if not, do like U did this on old bootloader from fastboot
6)Flash twrp as usual. In archive I already include this, you can flash it with
Code:
fastboot flash recovery twrp.img
And install magisk/SSu
Attention: if you wanna get full access for /data partition from twrp, you should flash patch with prevent autoencrypt. I did not do this, system access is enought for me.
But before you root your device, U have to erase data partition, coz root patch boot partition too, patched boot can not load stocky encrypted data. After data format you can flash magisk. When you boot phone, it will encrypt data partition and you get installed Magisk and ecrypted data
Original system/boot images, restore them with twrp https://mega.nz/#!ziJxCCqA!C0lG5hUcOGwl2ER0Mp342lfx5_DOIzalAi7RExR6nro
Click to expand...
Click to collapse
Hi, thank to you I have unlocked my phone in 8.1.
But when I tried to downgrade to nougat, home and fingerprint botton won't work. I had tried relocking bootloader and lock again using nougat method, but still home button won't work.
Do you have any idea to fix home button so I can use nougat firmware in this device?

komtek said:
Hi, thank to you I have unlocked my phone in 8.1.
But when I tried to downgrade to nougat, home and fingerprint botton won't work. I had tried relocking bootloader and lock again using nougat method, but still home button won't work.
Do you have any idea to fix home button so I can use nougat firmware in this device?
Click to expand...
Click to collapse
You should flash service nougat

Dreamject said:
You should flash service nougat
Click to expand...
Click to collapse
I'm sorry, can you tell me what service nougat is? Did you mean play service, or other service?

komtek said:
I'm sorry, can you tell me what service nougat is? Did you mean play service, or other service?
Click to expand...
Click to collapse
you can find service fw at least on 4pda. Service fw contained more data than usual fw

Dreamject said:
you can find service fw at least on 4pda. Service fw contained more data than usual fw
Click to expand...
Click to collapse
Thanks to @Dreamject I have managed broken fingerprint sensor when I tried to downgrade to 7.1
Here is quick guide to fix broken fp sensor in 7.1:
(Prerequisites: adb driver installed on computer)
1. Download service firmware nougat v.232-AFT https://yadi.sk/d/IzR3ITht2IlHxw (source 4pda)
2. Extract firmware to root C://
3. Open flashall_AFT.bat
4. Go to fastboot mode and connect the phone to computer. (NOTE: YOU MUST ON 8.1 FIRMWARE UNLESS FP SENSOR WON'T FIXED)
5. Wait ~10 minutes until finished.

Mother Russia)

By the way, be careful, coz it contains as o remember service Oreo too.
If file name 14.2016 it's nougat, if 15.2016 it's Oreo

link is gone, pls fix the link

Bootloader ReLocked Problem same as WW-15.2016.1812.505,So contiue used these step

Dreamject said:
As you know, on 8.1 we still have ununlockable bootloader. But it's quite simple to fix, just flash 'old' bootloader
It's unofficial method
1) Go to fastboot bode (keep + button on reboot/boot your phone)
2) Use service firmware or download this https://vk.com/doc275347426_479517439 , open command promp (start.bat)
3) VERY IMPORTANT
you should know your platfotm. As I know, 2 GB (my phone) have 8917 processor, 3gb/32 have 8937. You can get your platform with this
Code:
fastboot getvar platform
4) I have 8917, so I type
Code:
fastboot flash aboot 8917_emmc_appsboot.mbn
fastboot flash abootbak 8917_emmc_appsboot.mbn
On 8937 type
Code:
fastboot flash aboot 8937_emmc_appsboot.mbn
fastboot flash abootbak 8937_emmc_appsboot.mbn
5) Reboot your phone, you should get 'device state unlocked' , if not, do like U did this on old bootloader from fastboot
6)Flash twrp as usual. In archive I already include this, you can flash it with
Code:
fastboot flash recovery twrp.img
And install magisk/SSu
Attention: if you wanna get full access for /data partition from twrp, you should flash patch with prevent autoencrypt. I did not do this, system access is enought for me.
But before you root your device, U have to erase data partition, coz root patch boot partition too, patched boot can not load stocky encrypted data. After data format you can flash magisk. When you boot phone, it will encrypt data partition and you get installed Magisk and ecrypted data
Original system/boot images, restore them with twrp https://mega.nz/#!ziJxCCqA!C0lG5hUcOGwl2ER0Mp342lfx5_DOIzalAi7RExR6nro
Click to expand...
Click to collapse
I've make a flashable which can used with ZF4 Max update ROM(script and binary based on WW-15.2016.1812.505,file is from OP post)
-Just flash it after stock ROM update

[GUIDE][HOW TO] Flashing with care & Surviving soft bricks with fastboot [CMD] [TIPS]

[GUIDE][HOW TO] Flashing with care & Surviving soft bricks with fastboot [CMD] [TIPS]
Hello guys, some of us are new to the A/B partitions. Flashing on wrong partition may end up in soft bricks. This is not a rooting guide, here I'm explaining how to handle flashing A/B partitions properly and survive soft bricks using fastboot . Always backup your data before flashing anything.
Those who still don't know about the A/B partitions, please take a look at this thread https://forum.xda-developers.com/oneplus-6/how-to/guide-noobs-guide-to-b-partitions-op6-t3816123
Prerequisites:
OnePlus 6T with unlocked or locked bootloader
A computer for running fastboot commands
You :laugh:
Rebooting
Rebooting your device via adb and fastboot
Code:
adb reboot //normal reboot
adb reboot recovery //reboot to recovery
adb reboot bootloader //reboot to fastboot (bootloader)
Code:
fastboot reboot //normal reboot
fastboot reboot bootloader //reboot to fastboot (bootloader)
Unlocking the Bootloader
Bootloader can be unlocked via fastboot
Code:
fastboot oem unlock
WARNING THIS WILL WIPE YOUR DATA
Working with A/B Partitions
There are two boot partitions on this device, named boot_a and boot_b respectively, they are not the “traditional” boot partitions. Both of these partitions contain a kernel and ramdisk like you are probably used to. The difference is that there is no recovery partition and the boot partition is new recovery partition. The A/B partitioning scheme can be quite confusing to users. There are actually two copies of many of the partitions. There is only one data (userdata) partition.
Slots
The concept of ‘slots’ comes into play to determine whether you are booting ‘slot A’ or ‘slot B’. We can determine which slot is ‘active’ or marked for booting via adb and fastboot:
Code:
adb shell getprop ro.boot.slot_suffix
Code:
fastboot getvar current-slot
Switching Slots
We can switch between slots via fastboot:
Code:
fastboot set_active other //switch to inactive slot
Code:
fastboot set_active (a or b) //switch to specified slot
Flashing/Booting
We can flash/boot (temporary flash) recovery/kernel via fastboot. To boot (what we call temporary flash) a kernel/recovery there is no need to switch/select any slot. Keep in mind that when we run the flash command instead of boot, it will wipe the specified partiton (you may lose your root & custom kernel)
Code:
fastboot boot boot.img or twrp_recovery.img
To flash permanently, first switch/select any slot you want or it will automatically flashed to the active slot. This may cause boot loop, always proceed with caution.
Code:
fastboot flash boot boot.img or twrp_recovery.img
Code:
fastboot flash recovery twrp_recovery.img
If your testing something, always use the inactive slot. Eg: if you want to test a custom rom, first back up your data then switch to the inactive slot and flash the custom rom, this will save your time (no need restore full backup only data).
Surviving Soft Bricks
Some possible simple solution we can try rather than using MSMTool or flashing the full rom.
When causing boot loops, try these:
Flash Magisk via recovery
Switch to the other slot via fastboot
Wipe data partiton via fastboot -w
When causing Bootloader crash, try these:
Turn off the phone by holding the power button (release after power off)
Hold both volume buttons
Now press power button
Phone will boot to fastboot
Now switch the other slot via fastboot
To be continued....

Just in case

This is my first A/B device so forgive my ignorance, I was wondering if its possible to flash two different roms on to different slots...like oxygen on one partition and lineage on other?
Also why twrp has two buttons 'slot a' and 'slot b' in reboot section?
The phone doesn't have recovery partition, so what happens on typing 'Fastboot flash recovery' command?

Thanks again for this tutorials. That's really helpful in understanding of the new Android features.
What'd be your advice on instructions to get stock kernel back? I couldn't find an appropriate command on how to do it

patelparth120595 said:
This is my first A/B device so forgive my ignorance, I was wondering if its possible to flash two different roms on to different slots...like oxygen on one partition and lineage on other?
Also why twrp has two buttons 'slot a' and 'slot b' in reboot section?
The phone doesn't have recovery partition, so what happens on typing 'Fastboot flash recovery' command?
Click to expand...
Click to collapse
You can install any rom on both slot, there is no problem. There is only one userdata partiton. The two buttons are for switching between slots, if you press slot a button, the recovery will mark slot a as bootable or active partition. On next boot or reboot rom from slot a will boot, this same thing is applied for slot b too. There is no dedicated partition for recovery , files for recovery are stored in system_root.

geminium said:
Thanks again for this tutorials. That's really helpful in understanding of the new Android features.
What'd be your advice on instructions to get stock kernel back? I couldn't find an appropriate command on how to do it
Click to expand...
Click to collapse
Get stock boot.img file and flash using fastboot
Code:
fastboot flash boot boot.img

AnoopKumar said:
You can install any rom on both slot, there is no problem. There is only one userdata partiton. The two buttons are for switching between slots, if you press slot a button, the recovery will mark slot a as bootable or active partition. On next boot or reboot rom from slot a will boot, this same thing is applied for slot b too. There is no dedicated partition for recovery , files for recovery are stored in system_root.
Click to expand...
Click to collapse
Thanks for the reply. Cleared all my doubts.

So could we have two ROMs and switch back and forth between on one device in this case?

geminium said:
So could we have two ROMs and switch back and forth between on one device in this case?
Click to expand...
Click to collapse
Because of one userdata partition, there will be some issues. If wipe data when switching roms, no issues then.

Man i could use some help patched the file moved it to harddrive tried fastboot flash boot boot.img (the patched one) and all i get is
C:\Users\seang\OneDrive\Desktop\Moto G Stylus 2021>fastboot flash boot boot.img
error: cannot open 'boot.img' Could you please make a guide with some pics or at least a step by step cause nothing i have tried has gotten root yet. Thanks!

Thanks to the OP.

[Q] How to backup Nubia Red Magic 3's boot, system and etc from phone?

Hello,
I purchased my Nubia Red Magic 3 CN ROM today. Before doing root, I'd like to backup boot, system from the phone unit itself using
Code:
adb pull
During on fastboot, connected on PC, I tried the command
Code:
adb shell ls /dev/block/bootdevice/by-name/*
but it says
Code:
error: no devices/emulators found
I just tried the command thinking it will work on most android phones.
what
Code:
adb shell ls
should I use?

I would just unpack the CN Rom boot, recovery, and system.img all there. Global ROM you have to for we have no Twrp or other custom recovery, for which one has to patch boot.img with Magisk then flash over in fastboot to root.

SuperDroidMe said:
I would just unpack the CN Rom boot, recovery, and system.img all there. Global ROM you have to for we have no Twrp or other custom recovery, for which one has to patch boot.img with Magisk then flash over in fastboot to root.
Click to expand...
Click to collapse
True I read that also somewhere. But for system, you need to unpack the system.new.dat.br
Found some helpful threads here on xda on how to unpack it.
The first one is brotli by trzpro
https://forum.xda-developers.com/android/help/tut-how-to-convert-dat-br-to-dat-t3723926
after unpacking it, you need to convert it to img
https://forum.xda-developers.com/an.../how-to-conver-lollipop-dat-files-to-t2978952
replying here for easy future reference