Wolf's ultimate flash and downgrade guide (NO ROOT NEEDED) (root opportunity for .21)

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wolf849

Senior Member
Mar 19, 2009
68
221
WARNING

This method will not work on any JB rom available, apparently google has patched the exploit.

Note that downgrading method for unrooted devices is highly experimental and may turn your device into worthless brick. Read this WHOLE thread carefully before you start doing anything with your Transformer.

MOD EDIT: It is reported that this method doesn't work with the new Jelly Bean firmwares on the TF201 and the TF300T,

Sorry, but I will not be able to support you between 3rd and 15th of May because I have to pass my final exams.
However feel free to post your questions in this topic I am sure that somebody will be able to help you.
Description
Method 1 - Rooted Devices
This method allows you to flash any update released by ASUS without need for custom recovery.
ROOT is required to unlock mmcblk0p4 write access for dd.


Method 2 - UnRooted Devices
This method allows you to flash any update released by ASUS, no mater for SKU etc.
It uses file linking trick to unlock mmcblk0p4 write access even when su is not present.


Method 3 - UnRooted Devices - Recommended
This method allows you to directly flash the recovery even on unrooted device. This may be used next to root your TF by prepared su package.
It uses file linking trick to unlock mmcblk0p4 write access.
Disclaimer

Despite both methods have been confirmed (by myself) to work, the whole process of flashing mmcblk0p4 with dd brings high risk of bricking device by for example file system corruption.

I do not take any responsibility for damaged or bricked devices. Before flashing you have to assume the risk and chances of geting bricked.

Under no circumstances should you brake cmd during blob file is flashed by dd. If that happens do not reboot. PM me and go on IRC
Requirements


  • BLOB file (look at links box at the bottom for few)
  • ADB enabled
  • Root acces (only method 1)

Notes​
Sorry for the mistakes, but English is not my native language PM me if you find any so I will be able to correct them.

Before posting a question look into FAQ maybe it have been already answered.

Guide is inspired by Turge who wrote similar article for TFP (link here). However whole 2nd method was invented and described by me.

Thanks go to:
Code:
[CENTER]
AndroidRoot.mobi - for RazorClaw
ViperBoy - for viperMOD rooting tool
jcase - for NachoRoot
sparkym3 - for his ICS rooting methods
Roach2010 - for all his work
sbiriguda - who inspired me to dig around symlinking
[/CENTER]

Instructions - Method 1 - Rooted
1. Upload the BLOB file to internal storage of your tab. (mounted as /sdcard)
2. Connect tablet to the computer and start ADB session.
3. When you will be in adb shell execute following comands:
Code:
su
dd if=/sdcard/blob of=/dev/block/mmcblk0p4
4. The command prompt will be empty as wnen nothing happen, do not panic wait until the end of the process. DO NOT INTERRUPT (it will take apx.3-10 min)
5. When you see the following message:
Code:
1066806+1 records in
1066806+1 records out
546204969 bytes transferred in 250.309 secs (2182122 bytes/sec)
(the numbers in resulted message may be diffrent but it has to have the same structure)
You can safety reboot the device by exiting shell and executing :
Code:
adb reboot
6. Once rebooted you will see ASUS EeePAD flashing progress bar. Be patient and wait till the end.
7. Tablet will reboot itself and start loading new system. (as it is first boot it may take few minutes)
8. Be happy from your new firmware.

ADDITIONAL OPTIONAL STEP

In some cases flashing previous firmware leaves data partition intact.
I suggest to clean it by booting with [vol down] and [power] pressed (you will see the info about the rom). Than wait until the screen with android and wipe data appear. Select wipe by switching with [vol down] and accepting with [vol up] pressed two times. It mostly happen when downgrading to HC from ICS.

Instructions - Method 2 - UnRooted
1. Upload the BLOB file to internal storage of your tab. (mounted as /sdcard)
2. Connect tablet to the computer and start ADB shell session.
3. When you will be in adb shell execute following commands:
Code:
mv /data/local/tmp /data/local/tmp.bak
ln -s /dev/block/mmcblk0p4 /data/local/tmp
exit
4. Now reboot your tab through:
Code:
adb reboot
5. Once you see ASUS loading screen you should be able to start ADB shell session again (if not just wait), than (in shell) execute:
Code:
dd if=/sdcard/blob of=/dev/block/mmcblk0p4
6. The command prompt will be empty as wnen nothing happen, do not panic wait until the end of the process. DO NOT INTERRUPT (it will take apx.3-10 min)
7. When you see the following message:
Code:
1066806+1 records in
1066806+1 records out
546204969 bytes transferred in 250.309 secs (2182122 bytes/sec)
(the numbers in resulted message may be diffrent but it has to have the same structure)
You can safety reboot the device by exiting shell and executing :
Code:
adb reboot
8. Once rebooted you will see ASUS EeePAD flashing progress bar. Be patient and wait till the end.
9. Tablet will reboot itself and start loading new system. (as it is first boot it may take few minutes)
10. Be happy from your new firmware.

ADDITIONAL OPTIONAL STEP

In some cases flashing previous firmware leaves data partition intact.
I suggest to clean it by booting with [vol down] and [power] pressed (you will see the info about the rom). Than wait until the screen with android and wipe data appear. Select wipe by switching with [vol down] and accepting with [vol up] pressed two times. It mostly happen when downgrading to HC from ICS.

Instructions - Method 3 - UnRooted

This will definitely not work with Transformer Prime continue only if you are owner of TF101 of TF101G

1. Upload the RECOVERYBLOB file to internal storage of your tab. (mounted as /sdcard)
2. Connect tablet to the computer and start ADB shell session.
3. When you will be in adb shell execute following commands:
Code:
mv /data/local/tmp /data/local/tmp.bak
ln -s /dev/block/mmcblk0p4 /data/local/tmp
exit
4. Now reboot your tab through:
Code:
adb reboot
5. Once you see ASUS loading screen you should be able to start ADB shell session again (if not just wait), than (in shell) execute (some times it gets longer, but do not panic it is normal):
Code:
dd if=/sdcard/recoveryblob of=/dev/block/mmcblk0p4
6. The command prompt will be empty as when nothing happen, do not panic wait until the end of the process. DO NOT INTERRUPT (it will take apx.3-10 min)
7. When you see the following message:
Code:
8860+1 records in
8860+1 records out
4536396 bytes transferred in 1.718 secs (2640509 bytes/sec)
(the numbers in resulted message may be different but it has to have the same structure)
You can safety reboot the device by exiting shell and executing :
Code:
adb reboot
8. Once rebooted you will see ASUS EeePAD flashing progress bar. Be patient and wait till the end.
9. Tablet will reboot itself and start loading new system. (as it is first boot it may take few minutes)
10. Be happy from your new recovery.

ADDITIONAL - ROOTING

11. Download this SU + Superuser.apk package and place it on internal memory or microsd
12. Boot to recovery. (turn off your TF and than boot with [vol down]+[power] pressed, once you see the letters identifying the system press [vol up]
13. Now you should be in custom recovery. Select 'Install from zip file' and then select the file on desired location internal or external.
14. Once flashing is done go back and select 'Reboot system'
15. Now you got freshly rooted Transformer. ENJOY

BLOBs

BLOB file can be extracted from any update file. It is contained inside XX_epad-user-x.x.x.x.zip achive. Where XX (e.g WW or TW) refers to SKU of firmware and x.x.x.x to its version (e.g 9.2.2.3)

Or you can pick up a few here ;)

Now they are ziped to reduce the sizes (MD5 value shows the control sum of each blob not zip) (sorry for hostings but I don't have space on dropbox any more, you may register to increase) (if you know faster mirror PM me)

NEW MIRROR SITE WITH ALMOST ALL FIRMWARES HERE

TF101/G BLOBs (Transformer)

Honeycomb

WW 8.6.6.19 - MD5: D63D60F6C71F5B614B338244D3788735 - or mirrors (1 2)

WW 8.6.6.23 - MD5: 1227F19BC4415661CACB05A483504953 - or mirrors (1 2)

Ice Cream Sandwich

US 9.2.1.11 - MD5: 4F6069430B20C35C8833F50DFA0FE0FD - or mirrors (1 2)

WW 9.2.1.17 - MD5: 5C78C28C31888943AB67CCE4B4448319

US 9.2.1.17 - MD5: 380CA6399374FF5F84154509365A83F7 - or mirrors (1 2)

TW 9.2.1.17 - MD5: CA52E4AD670DFFA29DC1CBA04A0A4164 - or mirrors (1 2)

WW 9.2.2.3 - MD5: 5D5A44069346C4D7D2740E4100520692 - or mirrors (1 2)

TW 9.2.2.3 - MD5: pending


TF201 BLOBs (Transformer Prime)

Honeycomb

WW 8.8.3.33 - MD5: 5136E579FAEDDFE15F6AAE623B6CB67D - (or mirrors 1 2)

Ice Cream Sandwich

WW 9.4.2.11 - MD5: B2668A3387924B19A91F74ABF5DBE4E8 - (mirror)

US 9.4.2.14 - MD5: EF2E635BD6921BFA9D01FC0E4DD0644B - (mirror)

WW 9.4.2.15 - MD5: 55122257B30E9376DF463F3C1A8BA702 - (or mirror 1 )

WW 9.4.2.21 - MD5: 1129DC2643BD0F5DC6C07B9A1B619548 - (or mirror 1 )

RECOVERYBLOBs (only for TF101)

Rburrow's Rogue XM Recovery (mirror) - MD5: 6EE759A84ED02F0D95A029EC245CFDC5 - thread

Hope it will help
Results​
Confirmed to work on both TF101/G (ASUS Transformer) and TF201 (ASUS Transformer Prime)

However keep in mind that TFP have to be locked in order to use second method otherwise you may brick your device.


It probably can be used with slider as well :)

I also confirmed that it is possible to root any official OTA (on TF101/G) by flashing recoveryblob containing custom recovery and than update.zip with su and superuser app.

Proven that Method 2 also work with 9.2.1.21 update to downgrade the software and reroot device. - thanks alvin612.

Method 2 may also work on locked Transformer Prime however be careful and read warning and disclaimer in this thread.

Click 'Thanks' if I helped you ;)
 
Last edited:

sbiriguda

Senior Member
Feb 3, 2011
307
155
L'Aquila
Let me just say this: you are a freaking genius. I didn't even think of symlinking /dev/block/mmcblk0p4 to /data/local/tmp so it would change ownership and permissions on reboot. This is f*ing brilliant!

Moreover, if you have a blob for CWM you can also use the second method to install it on an unrooted device and then root it using the customary update.zip with su and superuser.apk (yes, even on 9.2.2.3 TF101Gs).

Again, great job! ;)
 

Woody

Retired Admin - Vacationing in Nanda Parbat
Nov 18, 2010
8,842
16,519
Immersed in Dark Matter
A big **sigh**, finally a solution for non-root users/ non-NVflash-ables to get back. I am rooted and will always be as long as the expliot is there but this should help many, many non-rooted people that are frustrated with ICS.

Many thanks.
 

hearts king101

Senior Member
Nov 1, 2010
728
146
Jizan
Just GENIUS

you are genius bro ;) thank u so much for this guide. I'll try it tomorrow bcuz it's late " 1:00 am " and report back later.

Thanks again :)

Edit: I couldn't wait until tomorrow so i said let's try it but something happened and now my tab is bricked ( Stuck on EEE Pad screen ) :(:(:(:(:(
 
Last edited:
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wolf849

Senior Member
Mar 19, 2009
68
221
you are genius bro ;) thank u so much for this guide. I'll try it tomorrow bcuz it's late " 1:00 am " and report back later.

Thanks again :)

Edit: I couldn't wait until tomorrow so i said let's try it but something happened and now my tab is bricked ( Stuck on EEE Pad screen ) :(:(:(:(:(

OK, easy come on #asus-transformer at webchat.freenode.net will try to manage something.
 
  • Like
Reactions: hearts king101

alvin612

Senior Member
Apr 17, 2011
80
18
OMG you saved my transformer!!!

Long story short, my tablet, as of 20mins ago, was in such an awkward status:
- has su and superuser.apk in /system/xbin
- all root checker apps say I'm NOT rooted
- on stock recovery but stock images put on external SD card won't get recognized
- whenever an app requests root, it got automatically denied by SuperUser.

and I saw this post....I'm back on 9.2.17 stock now!!:D

Thanks a million! ln -s...genius!!
 

kevchaps

Member
Jan 4, 2012
49
5
Long story short, my tablet, as of 20mins ago, was in such an awkward status:
- has su and superuser.apk in /system/xbin
- all root checker apps say I'm NOT rooted
- on stock recovery but stock images put on external SD card won't get recognized
- whenever an app requests root, it got automatically denied by SuperUser.

and I saw this post....I'm back on 9.2.17 stock now!!:D

Thanks a million! ln -s...genius!!

Did you start off with 9.2.1.21? Or just fixing your botched 9.2.1.17?
 

hearts king101

Senior Member
Nov 1, 2010
728
146
Jizan
You are genius wolf

:D:D:D:D:D:D:D:D:D

It worked :eek:. Yes Yes Yes Yes Yes



THANK YOU SO MUCH WOLF

FYI: I copied 3 files named ( EP101_SDUPDATE, EP101-SDUPDATE, EP101SDUPDATE ) so i don't know which one worked bcuz i tried the 1st name yesterday but didn't work :confused:.
 
Last edited:

wolf849

Senior Member
Mar 19, 2009
68
221
  • Like
Reactions: Rodriger

msl400

Member
Feb 16, 2010
38
4
Thank you very much, i'm back on 8.6.6.23 from 9.2.2.23. The only thing i had, after the flashing Android want not boot. I made a wipe and everything is ok.

Thank you again.
 

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  • 192
    WARNING

    This method will not work on any JB rom available, apparently google has patched the exploit.

    Note that downgrading method for unrooted devices is highly experimental and may turn your device into worthless brick. Read this WHOLE thread carefully before you start doing anything with your Transformer.

    MOD EDIT: It is reported that this method doesn't work with the new Jelly Bean firmwares on the TF201 and the TF300T,

    Sorry, but I will not be able to support you between 3rd and 15th of May because I have to pass my final exams.
    However feel free to post your questions in this topic I am sure that somebody will be able to help you.
    Description
    Method 1 - Rooted Devices
    This method allows you to flash any update released by ASUS without need for custom recovery.
    ROOT is required to unlock mmcblk0p4 write access for dd.


    Method 2 - UnRooted Devices
    This method allows you to flash any update released by ASUS, no mater for SKU etc.
    It uses file linking trick to unlock mmcblk0p4 write access even when su is not present.


    Method 3 - UnRooted Devices - Recommended
    This method allows you to directly flash the recovery even on unrooted device. This may be used next to root your TF by prepared su package.
    It uses file linking trick to unlock mmcblk0p4 write access.
    Disclaimer

    Despite both methods have been confirmed (by myself) to work, the whole process of flashing mmcblk0p4 with dd brings high risk of bricking device by for example file system corruption.

    I do not take any responsibility for damaged or bricked devices. Before flashing you have to assume the risk and chances of geting bricked.

    Under no circumstances should you brake cmd during blob file is flashed by dd. If that happens do not reboot. PM me and go on IRC
    Requirements


    • BLOB file (look at links box at the bottom for few)
    • ADB enabled
    • Root acces (only method 1)

    Notes​
    Sorry for the mistakes, but English is not my native language PM me if you find any so I will be able to correct them.

    Before posting a question look into FAQ maybe it have been already answered.

    Guide is inspired by Turge who wrote similar article for TFP (link here). However whole 2nd method was invented and described by me.

    Thanks go to:
    Code:
    [CENTER]
    AndroidRoot.mobi - for RazorClaw
    ViperBoy - for viperMOD rooting tool
    jcase - for NachoRoot
    sparkym3 - for his ICS rooting methods
    Roach2010 - for all his work
    sbiriguda - who inspired me to dig around symlinking
    [/CENTER]

    Instructions - Method 1 - Rooted
    1. Upload the BLOB file to internal storage of your tab. (mounted as /sdcard)
    2. Connect tablet to the computer and start ADB session.
    3. When you will be in adb shell execute following comands:
    Code:
    su
    dd if=/sdcard/blob of=/dev/block/mmcblk0p4
    4. The command prompt will be empty as wnen nothing happen, do not panic wait until the end of the process. DO NOT INTERRUPT (it will take apx.3-10 min)
    5. When you see the following message:
    Code:
    1066806+1 records in
    1066806+1 records out
    546204969 bytes transferred in 250.309 secs (2182122 bytes/sec)
    (the numbers in resulted message may be diffrent but it has to have the same structure)
    You can safety reboot the device by exiting shell and executing :
    Code:
    adb reboot
    6. Once rebooted you will see ASUS EeePAD flashing progress bar. Be patient and wait till the end.
    7. Tablet will reboot itself and start loading new system. (as it is first boot it may take few minutes)
    8. Be happy from your new firmware.

    ADDITIONAL OPTIONAL STEP

    In some cases flashing previous firmware leaves data partition intact.
    I suggest to clean it by booting with [vol down] and [power] pressed (you will see the info about the rom). Than wait until the screen with android and wipe data appear. Select wipe by switching with [vol down] and accepting with [vol up] pressed two times. It mostly happen when downgrading to HC from ICS.

    Instructions - Method 2 - UnRooted
    1. Upload the BLOB file to internal storage of your tab. (mounted as /sdcard)
    2. Connect tablet to the computer and start ADB shell session.
    3. When you will be in adb shell execute following commands:
    Code:
    mv /data/local/tmp /data/local/tmp.bak
    ln -s /dev/block/mmcblk0p4 /data/local/tmp
    exit
    4. Now reboot your tab through:
    Code:
    adb reboot
    5. Once you see ASUS loading screen you should be able to start ADB shell session again (if not just wait), than (in shell) execute:
    Code:
    dd if=/sdcard/blob of=/dev/block/mmcblk0p4
    6. The command prompt will be empty as wnen nothing happen, do not panic wait until the end of the process. DO NOT INTERRUPT (it will take apx.3-10 min)
    7. When you see the following message:
    Code:
    1066806+1 records in
    1066806+1 records out
    546204969 bytes transferred in 250.309 secs (2182122 bytes/sec)
    (the numbers in resulted message may be diffrent but it has to have the same structure)
    You can safety reboot the device by exiting shell and executing :
    Code:
    adb reboot
    8. Once rebooted you will see ASUS EeePAD flashing progress bar. Be patient and wait till the end.
    9. Tablet will reboot itself and start loading new system. (as it is first boot it may take few minutes)
    10. Be happy from your new firmware.

    ADDITIONAL OPTIONAL STEP

    In some cases flashing previous firmware leaves data partition intact.
    I suggest to clean it by booting with [vol down] and [power] pressed (you will see the info about the rom). Than wait until the screen with android and wipe data appear. Select wipe by switching with [vol down] and accepting with [vol up] pressed two times. It mostly happen when downgrading to HC from ICS.

    Instructions - Method 3 - UnRooted

    This will definitely not work with Transformer Prime continue only if you are owner of TF101 of TF101G

    1. Upload the RECOVERYBLOB file to internal storage of your tab. (mounted as /sdcard)
    2. Connect tablet to the computer and start ADB shell session.
    3. When you will be in adb shell execute following commands:
    Code:
    mv /data/local/tmp /data/local/tmp.bak
    ln -s /dev/block/mmcblk0p4 /data/local/tmp
    exit
    4. Now reboot your tab through:
    Code:
    adb reboot
    5. Once you see ASUS loading screen you should be able to start ADB shell session again (if not just wait), than (in shell) execute (some times it gets longer, but do not panic it is normal):
    Code:
    dd if=/sdcard/recoveryblob of=/dev/block/mmcblk0p4
    6. The command prompt will be empty as when nothing happen, do not panic wait until the end of the process. DO NOT INTERRUPT (it will take apx.3-10 min)
    7. When you see the following message:
    Code:
    8860+1 records in
    8860+1 records out
    4536396 bytes transferred in 1.718 secs (2640509 bytes/sec)
    (the numbers in resulted message may be different but it has to have the same structure)
    You can safety reboot the device by exiting shell and executing :
    Code:
    adb reboot
    8. Once rebooted you will see ASUS EeePAD flashing progress bar. Be patient and wait till the end.
    9. Tablet will reboot itself and start loading new system. (as it is first boot it may take few minutes)
    10. Be happy from your new recovery.

    ADDITIONAL - ROOTING

    11. Download this SU + Superuser.apk package and place it on internal memory or microsd
    12. Boot to recovery. (turn off your TF and than boot with [vol down]+[power] pressed, once you see the letters identifying the system press [vol up]
    13. Now you should be in custom recovery. Select 'Install from zip file' and then select the file on desired location internal or external.
    14. Once flashing is done go back and select 'Reboot system'
    15. Now you got freshly rooted Transformer. ENJOY

    BLOBs

    BLOB file can be extracted from any update file. It is contained inside XX_epad-user-x.x.x.x.zip achive. Where XX (e.g WW or TW) refers to SKU of firmware and x.x.x.x to its version (e.g 9.2.2.3)

    Or you can pick up a few here ;)

    Now they are ziped to reduce the sizes (MD5 value shows the control sum of each blob not zip) (sorry for hostings but I don't have space on dropbox any more, you may register to increase) (if you know faster mirror PM me)

    NEW MIRROR SITE WITH ALMOST ALL FIRMWARES HERE

    TF101/G BLOBs (Transformer)

    Honeycomb

    WW 8.6.6.19 - MD5: D63D60F6C71F5B614B338244D3788735 - or mirrors (1 2)

    WW 8.6.6.23 - MD5: 1227F19BC4415661CACB05A483504953 - or mirrors (1 2)

    Ice Cream Sandwich

    US 9.2.1.11 - MD5: 4F6069430B20C35C8833F50DFA0FE0FD - or mirrors (1 2)

    WW 9.2.1.17 - MD5: 5C78C28C31888943AB67CCE4B4448319

    US 9.2.1.17 - MD5: 380CA6399374FF5F84154509365A83F7 - or mirrors (1 2)

    TW 9.2.1.17 - MD5: CA52E4AD670DFFA29DC1CBA04A0A4164 - or mirrors (1 2)

    WW 9.2.2.3 - MD5: 5D5A44069346C4D7D2740E4100520692 - or mirrors (1 2)

    TW 9.2.2.3 - MD5: pending


    TF201 BLOBs (Transformer Prime)

    Honeycomb

    WW 8.8.3.33 - MD5: 5136E579FAEDDFE15F6AAE623B6CB67D - (or mirrors 1 2)

    Ice Cream Sandwich

    WW 9.4.2.11 - MD5: B2668A3387924B19A91F74ABF5DBE4E8 - (mirror)

    US 9.4.2.14 - MD5: EF2E635BD6921BFA9D01FC0E4DD0644B - (mirror)

    WW 9.4.2.15 - MD5: 55122257B30E9376DF463F3C1A8BA702 - (or mirror 1 )

    WW 9.4.2.21 - MD5: 1129DC2643BD0F5DC6C07B9A1B619548 - (or mirror 1 )

    RECOVERYBLOBs (only for TF101)

    Rburrow's Rogue XM Recovery (mirror) - MD5: 6EE759A84ED02F0D95A029EC245CFDC5 - thread

    Hope it will help
    Results​
    Confirmed to work on both TF101/G (ASUS Transformer) and TF201 (ASUS Transformer Prime)

    However keep in mind that TFP have to be locked in order to use second method otherwise you may brick your device.


    It probably can be used with slider as well :)

    I also confirmed that it is possible to root any official OTA (on TF101/G) by flashing recoveryblob containing custom recovery and than update.zip with su and superuser app.

    Proven that Method 2 also work with 9.2.1.21 update to downgrade the software and reroot device. - thanks alvin612.

    Method 2 may also work on locked Transformer Prime however be careful and read warning and disclaimer in this thread.

    Click 'Thanks' if I helped you ;)
    14
    *THIS TOOL IS USING WOLF'S 2nd method of downgrading, this is Viperboys one click tool, I modded to add Wolf's downgrade*

    ONE CLICK Downgrade, using Wolf's method and root tool (thanks to viperboy)
    I modded ViperMods awesome prime tool, to add an option to one click downgrade, using wolf's no root method :D. Just put the blob of FW you want to go to on the root of your primes internal memory, then run option 1 on my modded vipermods tool :D

    99.9% credit go to -Viperboy- and Wolf849 :D i just added option in viperMOD's tool

    EDIT: Fixed error in script

    Download:
    https://docs.google.com/uc?id=0B8gHyfs-S25Lal9KOWFQbWtzalE&export=download

    http://205.196.122.126/9jvynozv3cpg...MOD+Primer+Tool+v4.5+-+Modded+by+bpear_v3.zip (mediafire direct link)

    http://d-h.st/KrP

    *NOTE* this is using Wolf's method 2 which is confirmed to work on prime, im not sure about tf101 etc. from here http://xdaforums.com/showthread.php?t=1622628

    Mirrors of WW and US .15 blob (TRANSFORMER PRIME): you have to extract the .zip, possibly twice, then there will be a blob file, put that on /sdcard
    http://xdaforums.com/showpost.php?p=25503960&postcount=47
    3
    Let me just say this: you are a freaking genius. I didn't even think of symlinking /dev/block/mmcblk0p4 to /data/local/tmp so it would change ownership and permissions on reboot. This is f*ing brilliant!

    Moreover, if you have a blob for CWM you can also use the second method to install it on an unrooted device and then root it using the customary update.zip with su and superuser.apk (yes, even on 9.2.2.3 TF101Gs).

    Again, great job! ;)
    3
    FAQ

    I'm confused, which BLOB file should I choose?

    You have to choose BLOB with the firmware you want to install e.g. if you are on 9.2.2.3 and want to downgrade to Honeycomb just choose BLOB file from 8.6.6.19 or 8.6.6.23


    Wolf help something happened to my tab, it wont boot up.

    If you let dd to finish all its job and after reboot you saw the flashing bar, but your ROM still don't want to boot up you have probably downgraded from ICS to HC. Just do the wipe by booting with [vol down] and [power] pressed (you will see the info about the rom). Than wait until the screen with android and wipe data appear. Select wipe by switching with [vol down] and accepting with [vol up] pressed two times. Than everything should be fine.


    I'm stuck on step 3 all the time I have message like -> failed on '/data/local/tmp' - Not a directory <- What should I do?

    It means that you have already symlinked something to /data/local/tmp and moved your previous tmp to tmp.bak. To fix that you can either execute:
    Code:
    rm /data/local/tmp.bak
    or:
    Code:
    mv /data/local/tmp /data/local/tmp.mad
    and repeat procedure.


    Can I root the latest firmware and keep my data untouched?

    Yes, on both TF and TFP. For TF101 use method 3.
    For TF201 backup your data with ASUS Backup utility, than do a downgrade, root and install OTA ROOT Keeper from Voodoo. After that update OTA and recover your root and data.



    Can this method be used to root TF301? (aka EeePAD Infinity)

    Unfortunately no, it only allows us to do a step back without root permissions and than apply a root. However I'm still working around ASUS Backup App as I have an idea of exploit (but not enough time to study apk more). If you are interested in this consider donation as I don't have access to any TF301 and that would speed up the researches.