[HOW-TO] Upgrade or Downgrade to any stock JB Firmware

[pjc21]

After almost a full day of flashing I now have a 100% successful method of flashing any stock JB Firmware
With this method I have been able to successfully flash any stock JB Firmware from 10.4.2.9 all the way through to 10.6.1.27.5 without issue.
unfortunately you can not go back to ICS bootloader or firmware (there is a signature mismatch issue here).

Try this at your own risk, I will not be responsible for a bricked device.

Recommend doing NVFlash first so your tablet is Unbrickable
NVFlash for ICS bootloader
NVFlash for JB bootloader

Warning:
If you flash an incorrect recovery to a 4.2 bootloader there is about a 90% chance that fastboot flash commands will now just freeze the tablet - When you attempt to flash via fastboot everything will seem to go ok on the command prompt but you will not see the blue progress bar on the tablet when flashing & the reboot command will not reboot the tablet after the flash command & nothing will have flashed to the tablet.

If this is the case try this solution.

Please read below for how to check your bootloader version and confirm your flashing the correct recovery.


Requirements:

• Must be unlocked (Method 1 seems to work fine for locked devices but must be unlocked for Method 2 to flash custom recovery).
• Must have working fastboot
• Working adb in recovery (optional). I use adb in this method for rebooting but this can be done manually with vol- & power.

Always make a backup first.

Files Needed:
Download the stock JB firmware you wish to flash from either the Asus website or from the Index thread here, be sure to download the correct SKU version you wish to use On your tablet you can check what SKU your using by going to settings>about tablet, scroll down to build number and you can see SKU version..

If using method 2 download the TWRP recovery you require, Here is a link to the TWRP thread. When you download a version of TWRP it will have a name like "openrecovery-twrp-2.5.0.0-tf300t-4.2.blob" - You can rename to something shorter for flashing if you like, I rename like so "twrp-2.5.0.0-4.2.blob".

What recovery to flash for bootloader version: example for TF300T model:

Check & confirm what bootloader your on - boot to bootloader menu (vol- & power) and look at the text in top left, your bootloader version number is there.

JB 4.1 firmwares

• If current bootloader = 10.4.2.9 - JB 4.1 - recovery to flash = TWRP "openrecovery-twrp-2.5.0.0-tf300t-JB.blob" or CWM
• If current bootloader = 10.4.2.13 - JB 4.1 - recovery to flash = TWRP "openrecovery-twrp-2.5.0.0-tf300t-JB.blob" or CWM
• If current bootloader = 10.4.2.17 - JB 4.1 - recovery to flash = TWRP "openrecovery-twrp-2.5.0.0-tf300t-JB.blob" or CWM
• If current bootloader = 10.4.2.18 - JB 4.1 - recovery to flash = TWRP "openrecovery-twrp-2.5.0.0-tf300t-JB.blob" or CWM
• If current bootloader = 10.4.2.20 - JB 4.1 - recovery to flash = TWRP "openrecovery-twrp-2.5.0.0-tf300t-JB.blob" or CWM

JB 4.2 Firmwares

• If current bootloader = 10.6.1.8 - JB 4.2 - recovery to flash = ONLY TWRP "openrecovery-twrp-2.4.4.0-tf300t-4.2.blob" - flashing a non-4.2 version of TWRP or any version of CWM will brick device. Also flashing 2.5.0.0-tf300t-4.2 on the 10.6.1.8 bootloader results in a split-screen issue.
  
• If current bootloader = 10.6.1.15.3 - JB 4.2 - recovery to flash = ONLY TWRP "openrecovery-twrp-2.5.0.0-tf300t-4.2.blob" - flashing a non-4.2 version of TWRP or any version of CWM will brick device.
  
• If current bootloader = 10.6.1.27.1 - JB 4.2 - recovery to flash = ONLY TWRP "openrecovery-twrp-2.5.0.0-tf300t-4.2.blob" - flashing a non-4.2 version of TWRP or any version of CWM will brick device.
  
• If current bootloader = 10.6.1.27.5 - JB 4.2 - recovery to flash = ONLY TWRP "openrecovery-twrp-2.5.0.0-tf300t-4.2.blob" - flashing a non-4.2 version of TWRP or any version of CWM will brick device.

My Notes about TWRP 2.4.4.0-4.2:
TWRP 2.4.4.0-4.2 will not mount my sandisk 64gb micro SDXC UHS-1 class 10 card, but previous versions of TWRP have no issue. I believe this is a UHS-1 issue. TWRP 2.5.0.0-4.2 has fixed this bug and and can now mount 64gb micro SDXC UHS-1 class 10 card again.


Method 1

1. Unzip the firmware zip you downloaded, there will be another zip file inside.
   
   Example:
   Lets say you choose WW 10.4.2.20 firmware. (same method apply's for any firmware version and SKU you choose - US, WW, JP, TW, CN)
   [*]Unzip "WW_epaduser_10_4_2_20_UpdateLauncher.zip"and you will find another zip inside "WW_epad-user-10.4.2.20.zip".
   [*]Now unzip the WW_epad-user-10.4.2.20.zip and you will find a "blob" file.
   [*]Now copy the blob file to your android-sdk\platform-tools folder.
   
   Now to the flashing:
   
2. With your device loaded in android go to settings, developer options and make sure they are on & usb debugging is on.
   [*]Plug device into PC with usb cable & boot to fastboot.
   
   Using adb commands
   
   Open command prompt (run as admin) & cd to you android-sdk\platform-tools folder.
   Check your PC can see your device
   

   adb devices

   You should get a list with you device s/n, if not then adb is not setup.
   Next
   

   adb reboot-bootloader

   or
   
   Manually boot to fastboot
   
   Hold vol- & power button to boot to bootloader then connect to PC.
   
   Fastboot will start automatically when connected to PC on the 4.2 bootloaders. On 4.1 bootloaders you will need to select the usb icon using vol- to highlight the usb icon and vol+ to select.
   
   Note:
   In bootloader NEVER select the Wipe Data icon or you will brick.
   
   
3. Once in fastboot open command prompt & cd to you android-sdk\platform-tools folder and type command
   

   fastboot devices

   and again here you should get a list with you device s/n, if not then fastboot is not setup.
   
   [*]If OK we can now flash the system blob we put in the platform-tools folder
   
   

   fastboot -i 0x0b05 flash staging blob

   This will take about 10 minutes to send & write system, you will see a progress bar on device when system is writing.
   
   [*]When complete
   
   

   fastboot reboot

This method should work fine but have found that sometimes the device will get stuck at the boot animation, if this happens method 2 works fine every time.

Method 2

1. Unzip the firmware zip you downloaded, there will be another zip file inside.
   
   Example:
   Lets say you choose WW 10.4.2.20 firmware. (same method applys for any firmware version and SKU you choose - US, WW, JP, TW, CN)
   [*]Unzip "WW_epaduser_10_4_2_20_UpdateLauncher.zip"and you will find another zip inside "WW_epad-user-10.4.2.20.zip".
   
   [*]Place a copy of the WW_epad-user-10.4.2.20.zip on your microSD card.
   [*]Now on PC unzip the WW_epad-user-10.4.2.20.zip and you will find a "blob" file.
   [*]Now copy the blob file to your android-sdk\platform-tools folder.
   
   [*]Now copy the "twrp-version.blob" file you downloaded to your android-sdk\platform-tools folder.
   --Make sure you have the correct twrp version for the firmware your flashing.
   
   Now to the flashing:
   
2. With your device loaded in android go to settings, developer options and make sure they are on & usb debugging is on.
   [*]Plug device into PC with usb cable & boot to fastboot.
   
   Using adb commands
   
   Open command prompt (run as admin) & cd to you android-sdk\platform-tools folder.
   Check your PC can see your device
   

   adb devices

   You should get a list with you device s/n, if not then adb is not setup.
   Next
   

   adb reboot-bootloader

   Manually boot to fastboot
   
   Hold vol- & power button to boot to bootloader then connect to PC
   
   Fastboot will start automatically when connected to PC on the 4.2 bootloaders. On 4.1 bootloaders you will need to select the usb icon using vol- to highlight usb icon and vol+ to select.
   
   Note:
   In bootloader NEVER select the Wipe Data icon or you will brick.
   
   
3. Once in fastboot open command prompt & cd to you android-sdk\platform-tools folder and type command.
   

   fastboot devices

   and again here you should get a list with you device s/n, if not then fastboot is not setup.
   
   [*]If OK we can now flash the system blob we put in the platform-tools folder.
   
   

   fastboot -i 0x0b05 flash staging blob

   This will take about 10 minutes to send & write system, you will see a progress bar on device when system is writing.
   
   [*]Once this has completed type in the command prompt.
   

   fastboot reboot-bootloader

   You can now check that your bootloader has upgraded/downgraded, look at the text in the top left of the bootloader screen and make sure it's changed to the firmware version you just flashed.
   
   [*]Now again depending on the bootloader version go to fastboot.
   
   Next
   [*]In the below command I am using "openrecovery-twrp-2.5.0.0-tf300t-JB.blob" for JB firmware 10.4.2.20, and shortened the name "twrp-JB.blob" so just change command according to TWRP version needed.
   

   fastboot -i 0x0b05 flash recovery twrp-JB.blob

   [*]Once this has completed type in the command prompt.
   

   fastboot reboot-bootloader

   [*]Now this time in bootloader select the "RCK" icon to enter twrp recovery.
   [*]In twrp recovery select "Wipe".
   [*]Here I do a complete wipe (cache, Dalvik cache, Factory Reset, System, Internal Storage & Format Data) I don't believe Internal Storage & Data Format are necessary but I like a full clean flash.
   
   [*]Once you have done full wipe type in command prompt.
   

   adb reboot-bootloader

   or manually reboot to bootloader, hold vol- and power button.
   
   [*]Now again in bootloader select the "RCK" icon to enter twrp recovery.
   [*]In twrp recovery disconnect your device usb cable from PC.
   
   [*]Select "Install" & select the firmware zip you copied to your external sd card and slide to flash/install.
   
   [*]Once completed reboot, you will get message at top of recovery saying there is no OS installed are you sure you want to reboot - slide to confirm yes, another message will popup asking if you want root permissions installed - I select NO "Do not install" you can probably select yes here if you want twrp to root.
   
   The device will reboot, you'll see a progress bar as the signature is being matched, it will reboot again when done.
   Now device will boot with the stock JB bootloader & firmware you have chosen.
   
   Done.
   

You can now flash twrp, then flash any custom rom for that firmware.


As I have said I have done this with all stock WW JB firmware available and can confirm that the bootloader does change and system will boot and run without any issues. But try at own risk.

Firmware I have done this with: Only tried with WW SKU

• 10.6.1.27.5
• 10.6.1.27.1
• 10.6.1.15.3
• 10.6.1.8
• 10.4.2.20
• 10.4.2.18
• 10.4.2.17
• 10.4.2.13
• 10.4.2.9

More Info:
Downgrading from CROMi-X back to CROMi-3.4.6

Upgrading from ICS to JB

If you this information is helpful please hit the thanks button.

 

[wetbiker7]

Nice work and thanks for sharing it PJC21. Looks like you've got quite a bit of time invested in this info. :thumbup:

Sent from my LG-LG855 using Xparent SkyBlue Tapatalk 2

 

[jimpmc]

Thank you for the detailed information. Couldn't one just flash the stock .zip file from TWRP, reboot, reinstall TWRP recovery from fastboot and then wipe in TWRP as you would do when upgrading? I have done that between JB releases before, but I guess the bootloader didn't change.

 

[pjc21]

Thank you for the detailed information. Couldn't one just flash the stock .zip file from TWRP, reboot, reinstall TWRP recovery from fastboot and then wipe in TWRP as you would do when upgrading? I have done that between JB releases before, but I guess the bootloader didn't change.

Yeah quite possibly, I didn't even think to try it that way :laugh:

However if just flashing the system blob via fastboot then rebooting, my devices will get to the boot animation screen and just sit there.

I do prefer being on the correct bootloader before flashing the firmware though and this way allows for that.

 

[tobdaryl]

Maybe consider making this two parts.
1. with twrp recovery installed
2. with stock recovery installed
Good info and needed!

Note: I should have added with twrp, fastboot, or adb to flash I always loose root and data. With stock if I am using the same version or anything numerically higher I keep root and data but going to a lower numeric I loose root and data.
I hope this is understandable.

 

[Q-Logic]

I can confirm that this method 101 % works. :good:
I have migrated from custom ROM 4.2.1 to factory 4.2.1.
After final reboot I lost root, but rooting afterwards gave me rooted factory 4.2.1. No problems at all.
Thanks for this.

 

[Keshukas]

I can confirm that this method 101 % works. :good:
I have migrated from custom ROM 4.2.1 to factory 4.2.1.
After final reboot I lost root, but rooting afterwards gave me rooted factory 4.2.1. No problems at all.
Thanks for this.

+1 works

Sent from my GT-I9100 using xda app-developers app

 

[funnel71]

OK, I have a question. I see this works with full ROMs from Asus, good. What about TWRP backups?

So, before I upgraded to 4.2.1, I took a TWRP backup of 4.1.1 latest v20 build. If I restored that backup via TWRP, would it work? Would the bootloader revert to the older one (with the USB icon)? My backup did include the boot partition, but I didn't know if this would brick the device.

Sent from my ASUS Transformer Pad TF300T using Tapatalk 2

 

[MrsColumbo]

Just to make sure ...

Have you actually downgraded from 4.2.1 to 4.1.1?

I'm on 4.2.1 (10.6.1.8; Energy Rom) at the moment and eager to browse all those nice custom roms that are based on 10.4.x.x. like cm 10.1 & co.

Since the 4.2 upgrade rearranged the file system i'm afraid of messing it up when reverting to pre-multiuser-versions ...

Also i'd love to have this nvflash brickproof thingie ...

You think I could give this a go?

 

[Q-Logic]

Have you actually downgraded from 4.2.1 to 4.1.1?

I'm on 4.2.1 (10.6.1.8; Energy Rom) at the moment and eager to browse all those nice custom roms that are based on 10.4.x.x. like cm 10.1 & co.

Since the 4.2 upgrade rearranged the file system i'm afraid of messing it up when reverting to pre-multiuser-versions ...

Also i'd love to have this nvflash brickproof thingie ...

You think I could give this a go?

To be honest - I'm not sure, I didn't downgrade, let pjc21 say did he. I would be afraid to do mess with file system just like you.
But I would be interested to try this if his downgrading method works.

 

[pjc21]

OK, I have a question. I see this works with full ROMs from Asus, good. What about TWRP backups?

So, before I upgraded to 4.2.1, I took a TWRP backup of 4.1.1 latest v20 build. If I restored that backup via TWRP, would it work? Would the bootloader revert to the older one (with the USB icon)? My backup did include the boot partition, but I didn't know if this would brick the device.

Sent from my ASUS Transformer Pad TF300T using Tapatalk 2

I'm not sure here, but would think no as the new update has a different file system arrangement. I myself would not try this as I really have no idea what would happen.

 

[pjc21]

Have you actually downgraded from 4.2.1 to 4.1.1?

I'm on 4.2.1 (10.6.1.8; Energy Rom) at the moment and eager to browse all those nice custom roms that are based on 10.4.x.x. like cm 10.1 & co.

Since the 4.2 upgrade rearranged the file system i'm afraid of messing it up when reverting to pre-multiuser-versions ...

Also i'd love to have this nvflash brickproof thingie ...

You think I could give this a go?

Yes I have downgraded from 4.2.1 (10.6.1.8) to 4.1.1 (10.4.2.20) and I have also downgraded through all the JB firmware back to the first JB firmware that came out 10.2.4.9 -28/08/2012- not that many people would want to go back that far but I was attempting to go all the way back to an ICS bootloader & firmware so I could access NVflash and become brickproof as my tab came with JB pre-loaded. When attempting to go from a JB bootloader & firmware to an ICS one there is a signature mismatch which I have not looked into as yet and am not sure it would even be possible to modify this to get a match. I will have a look when I get the time and look at the differences between the JB & ICS signatures to see if it might be possible to modify these.

 

[MrsColumbo]

Works fine

Yes I have downgraded from 4.2.1 (10.6.1.8) to 4.1.1 (10.4.2.20) and I have also downgraded through all the JB firmware back to the first JB firmware that came out 10.2.4.9 -28/08/2012- not that many people would want to go back that far but I was attempting to go all the way back to an ICS bootloader & firmware so I could access NVflash and become brickproof as my tab came with JB pre-loaded. When attempting to go from a JB bootloader & firmware to an ICS one there is a signature mismatch which I have not looked into as yet and am not sure it would even be possible to modify this to get a match. I will have a look when I get the time and look at the differences between the JB & ICS signatures to see if it might be possible to modify these.

Witch much satisfaction I can confirm this working. Had to sideload the update zip, though, 'cause I forgot to copy it to my external micro sd card. in the course I ****ed up the update (progress indicator not progressing, so i did a vol-+power-reset, subsequently rom did not load), but adb-d recovery again, inserted micro sd and did the update (downdate) to 10.4.2.20. running cm 10.1 nightly now.

Yeah, this brickproof mod sounds really good. I wouldn't want to miss up on jb's smoothness, though. IMHO JB and ICS are worlds apart. Maybe those guys give it a go with a 4.2-brickproof-mod one fine day

Thanks pjc21 for this outstandig work. This is what Android OS is about: being able to explore all possibilities of a fine piece of hardware you actually own instead of being led on a leash by a corporation. :good::good::good:

 

[treo4life]

This worked pretty easy, returning from 4.2.1 ( 10.6.1.8) I flashed the 4.1.1 (10.4.2.20) blob through fast boot,then flashed twrp 2.3.3.0 in fast boot, rebooted into recovery restored my 4.1.1 backup and all is well.

 

[wetbiker7]

Yes I have downgraded from 4.2.1 (10.6.1.8) to 4.1.1 (10.4.2.20) and I have also downgraded through all the JB firmware back to the first JB firmware that came out 10.2.4.9 -28/08/2012- not that many people would want to go back that far but I was attempting to go all the way back to an ICS bootloader & firmware so I could access NVflash and become brickproof as my tab came with JB pre-loaded. When attempting to go from a JB bootloader & firmware to an ICS one there is a signature mismatch which I have not looked into as yet and am not sure it would even be possible to modify this to get a match. I will have a look when I get the time and look at the differences between the JB & ICS signatures to see if it might be possible to modify these.

Please update us on your progress. Everything I've read says that going back to ICS for NVFlash cannot be done if the tablet came with JB. Thanks.

Sent from my LG-LG855 using Xparent SkyBlue Tapatalk 2

 

[treo4life]

Please update us on your progress. Everything I've read says that going back to ICS for NVFlash cannot be done if the tablet came with JB. Thanks.

Sent from my LG-LG855 using Xparent SkyBlue Tapatalk 2

He stated you cannot go back to ICS in the first post,, but you can switch JB firmware pretty easy.

 

[wetbiker7]

He stated you cannot go back to ICS in the first post,, but you can switch JB firmware pretty easy.

Exactly. But........ he also said he was going to try and modify the signatures to see if he can get them to match. If he can succeed, it will be a huge breakthrough.

Sent from my LG-LG855 using Xparent SkyBlue Tapatalk 2

 

[treo4life]

That's true, don't know if he is going to try to tackle that one though.. would be nice to have the option...

Sent from my EVO using xda premium

 

[wetbiker7]

That's true, don't know if he is going to try to tackle that one though.. would be nice to have the option...

Sent from my EVO using xda premium

No doubt. Hopefully he'll continue working on it.

Sent from my LG-LG855 using Xparent SkyBlue Tapatalk 2

 

[ntunit]

I just received my new tablet ... Need to downgrade to 4.1.1 to be able to run AOSP Rom.

Thanks for the procedure. I will give it a try.