[GUIDE][BRICKED] [BOOTS ONLY TO RECOVERY][All ASUS TRANFORMERS]

lj50036 · Aug 21, 2014

This is a general users guide to unbrick your Transformer tablet.

This guide will help you if your Asus tablet will only boot into recovery

and the command

Code:

adb reboot-bootloader

does not work to get you booted back to bootloader screen ..

If the above command works then skip to the first fastboot command ..

WHAT YOU NEED

An Asus tablet that will only boot into recovery …
Woking adb and fastboot on your PC
Windows drivers (if using Windows)
A fully charged tablet
Asus data cable
Stock firmware blob (from Asus's web site, make sure you get the right one)
_that's bootit.ko (unzipped and placed with fastboot.exe)

Downloads

Asus Stock firmware---MAKE SURE YOU GET THE CORRECT SKU FOR YOUR TRANSFORMER TABLET
click me

_that's bootit.ko----click me

INSTRUCTIONS

Extract your stock firmware in your downloads folder twice...You will see a blob file rename it boot.blob and move it to the same folder as your fastboot.exe or if in linux to your home folder

Unzip the bootit.ko and place it wth the above blob file.

Let start with this command to make sure that your PC can see your table as an ADB device in recovery

Code:

adb devices

OUTPUT

Code:

[email protected] ~ $ adb devices
List of devices attached 
015c7d7a445c260c	recovery

Then lets push the bootit.ko to the root of the device like this

Code:

adb push bootit.ko /

OUTPUT

Code:

[email protected] ~ $ adb push bootit.ko /
673 KB/s (27690 bytes in 0.040s)

Then lets insmod this .ko file

Code:

adb shell insmod /bootit.ko

This should reboot the tablet into the bootloader menu, lets verifiy.

Once in the bootloader screen lets make sure your PC can see the device in fastboot.

Code:

fastboot devices

OUTPUT

Code:

[email protected] ~ $ fastboot devices 
015c7d7a445c260c	fastboot

So now its time to erase the misc & cache partitions, as that is most likely the partitions that is making it boot to recovery...

Code:

fastboot erase misc

OUTPUT

Code:

[email protected] ~ $ fastboot erase misc
erasing 'misc'...
OKAY [  1.021s]
finished. total time: 1.021s

Code:

fastboot erase cache

OUTPUT

Code:

[email protected] ~ $ fastboot erase cache
******** Did you mean to fastboot format this partition?
erasing 'cache'...
OKAY [  2.096s]
finished. total time: 2.096s

Once these two command run with OKAY as the OUTPUT .

It is time to make sure we can reboot into the bootloader with the hardware buttons

So from where you are at in the bootloader screen use the VOL DOWN & POWER buttons to boot the tab back into the bootloader screen ..

Run these command in fastboot in this order

The next command is to just verify your computer can see your device

Code:

fastboot devices

OUTPUT

Code:

[email protected]:~ > fastboot devices
015d2bbce2501405        fastboot

Code:

fastboot erase system

OUTPUT

Code:

[email protected]:~ > fastboot erase system
******** Did you mean to fastboot format this partition?
erasing 'system'...
OKAY [  2.954s]
finished. total time: 2.954s

Code:

fastboot erase recovery

OUTPUT

Code:

[email protected]a51:~ > fastboot erase recovery
erasing 'recovery'...
OKAY [  1.945s]
finished. total time: 1.945s

Code:

fastboot -w

OUTPUT

Code:

[email protected]:~ > fastboot -w
erasing 'userdata'...
OKAY [ 23.188s]
formatting 'userdata' partition...
Creating filesystem with parameters:
    Size: 29618601984
    Block size: 4096
    Blocks per group: 32768
    Inodes per group: 8192
    Inode size: 256
    Journal blocks: 32768
    Label: 
    Blocks: 7231104
    Block groups: 221
    Reserved block group size: 1024
Created filesystem with 11/1810432 inodes and 157662/7231104 blocks
sending 'userdata' (139133 KB)...
writing 'userdata'...
OKAY [ 26.358s]
erasing 'cache'...

At this point it will either hangs on erasing 'cache'
Or it will give you an error, either way you will need to
reboot the tablet back into fastboot with the hardware buttons
Once that is done continue on the path

Code:

fastboot erase boot

OUTPUT

Code:

[email protected]:~ > fastboot erase boot
erasing 'boot'...
OKAY [  1.209s]
finished. total time: 1.209s

Code:

fastboot erase misc

OUTPUT

Code:

[email protected]:~ > fastboot erase misc
erasing 'misc'...
OKAY [  0.978s]
finished. total time: 0.978s

Code:

fastboot erase cache

OUTPUT

Code:

[email protected]:~ >  fastboot erase cache
******** Did you mean to fastboot format this partition?
erasing 'cache'...
OKAY [  2.843s]
finished. total time: 2.843s

Code:

fastboot -i 0x0B05 flash system boot.blob

During the sending/writing process of this step you will get the blue bar on your screen.....

OUTPUT

Code:

[email protected]:~ > fastboot -i 0x0B05 flash system boot.blob
erasing 'system'...
OKAY [  2.339s]
sending 'system' (800927 KB)...
OKAY [133.094s]
writing 'system'...
[OKAY [178.036s]
finished. total time: 313.469s

Code:

fastboot -i 0x0B05 reboot

OUTPUT

Code:

[email protected]:~ > fastboot -i 0x0B05 reboot
rebooting...
finished. total time: 0.020s

Let it boot into stock ROM ...

lj50036 · Aug 21, 2014

Credits

@_that for his bootit.ko

TEAM CROMBi and TEAM ZOMBi-X @sbdags @hardslog

lj50036 · Aug 21, 2014

Troubleshooting

Here is some troubleshooting

Check out this thread for fasboot.exe, adb.exe and driver help ...CLICK ME

LetMeKnow · Aug 20, 2014

@lj50036
A typo on your very first command: adb device?

Edit: What would you recommend if the userdata is corrupted and have only fastboot/adb? fastboot format data-partition? Thanks...

lj50036 · Aug 20, 2014 at 6:03 PM

LetMeKnow said:
@lj50036
A typo on your very first command: adb device?

Edit: What would you recommend if the userdata is corrupted and have only fastboot/adb? fastboot format data-partition? Thanks...

Fixed let me know if you see anymore ..

Thx @LetMeKnow

lj50036 · Aug 20, 2014 at 6:09 PM

LetMeKnow said:
@lj50036
A typo on your very first command: adb device?

Edit: What would you recommend if the userdata is corrupted and have only fastboot/adb? fastboot format data-partition? Thanks...

I am going to get to this once you have fastboot back and you can boot with hardware buttons then its just like @Buster99's

guide but there is one very important command that he leaves out ..

I will post the rest of the guide after bit ...

Thx Josh

_that · Aug 20, 2014 at 8:03 PM

Here is the original thread where the bootit module was tested for the first time -> http://forum.xda-developers.com/showthread.php?t=2291974

The problem was that the installed recovery was too old and incompatible with the bootloader and so could not access the eMMC at all. The bootloader command to boot to recovery is stored in the MSC partition (mmcblk0p3), and the recovery could not clear it. Since the bootloader checks the MSC partition before checking for volume-down, it is impossible to get to fastboot without some additional kick in the butt (aka "bootit.ko").

The correct bootit.ko file to use is the one in "bootit-bootloader.zip": http://forum.xda-developers.com/attachment.php?attachmentid=1985941&d=1369339132 - the older version turned out to be too weak. Note that this is a zipped kernel module, not a recovery-installable ZIP. You need to unzip it on your PC before adb push.

After making it to the bootloader menu and working fastboot, you can fastboot flash a current version of TWRP and install the custom ROM of your choice. No real need for the stock blob, unless you want to make sure you have the current bootloader and a known working ROM.

Here is another thread where bootit.ko didn't help, maybe it was really a hardware problem. But lots of good background info from me.

-> http://forum.xda-developers.com/showthread.php?t=2437376

And here is another success story -> http://forum.xda-developers.com/showthread.php?p=47525770

lj50036 · Aug 20, 2014 at 8:12 PM

_that said:
Here is the original thread where the bootit module was tested for the first time -> http://forum.xda-developers.com/showthread.php?t=2291974

The problem was that the installed recovery was too old and incompatible with the bootloader and so could not access the eMMC at all. The bootloader command to boot to recovery is stored in the MSC partition (mmcblk0p3), and the recovery could not clear it. Since the bootloader checks the MSC partition before checking for volume-down, it is impossible to get to fastboot without some additional kick in the butt (aka "bootit.ko").

The correct bootit.ko file to use is the one in "bootit-bootloader.zip": http://forum.xda-developers.com/attachment.php?attachmentid=1985941&d=1369339132 - the older version turned out to be too weak. Note that this is a zipped kernel module, not a recovery-installable ZIP. You need to unzip it on your PC before adb push.

After making it to the bootloader menu and working fastboot, you can fastboot flash a current version of TWRP and install the custom ROM of your choice. No real need for the stock blob, unless you want to make sure you have the current bootloader and a known working ROM.

Here is another thread where bootit.ko didn't help, maybe it was really a hardware problem. But lots of good background info from me. -> http://forum.xda-developers.com/showthread.php?t=2437376

And here is another success story -> http://forum.xda-developers.com/showthread.php?p=47525770

Thx _that I did update the OP with the correct bootit.ko ...

berndblb · Aug 21, 2014 at 7:46 AM

lj50036 said:
Thx _that I did update the OP with the correct bootit.ko ...

Great stuff! Thanks for this thread Josh!

Now , if I understand this correctly, the insmod command injects a command into the kernel to boot straight to the bootloader before checking misc to break that 'forced reboot to recovery' cycle.
Kinda correct?

In another thread @_that stated once that

Code:

fastboot getvar all

does not return misc as a supported partiton and that

Code:

fastboot erase misc

only "theoretically" erases misc partition. Is that confirmed now?

You guys are great! So much fun to learn this...

lvrijn · Feb 22, 2010 34 1 0

I tried to follow this but i get this output:

After pushing bootit.ko to the root and insmod, the transformer reboots directly in the bootloader.
When try fastboot devices, nothing happens just the next line to fill in a command.

Also, when trying then to fastboot erase misc, it hangs with 'waiting for devices'..

berndblb · Aug 21, 2014 at 8:50 AM

lvrijn said:
I tried to follow this but i get this output:

After pushing bootit.ko to the root and insmod, the transformer reboots directly in the bootloader.
When try fastboot devices, nothing happens just the next line to fill in a command.

Also, when trying then to fastboot erase misc, it hangs with 'waiting for devices'..

Did you have a working fastboot driver on your PC before you got into this pickle?
Give us a detailed description on why you tried this procedure.

lvrijn · Aug 21, 2014

berndblb said:
Did you have a working fastboot driver on your PC before you got into this pickle?
Give us a detailed description on why you tried this procedure.

Thanks for the advice.
It was not the driver, if was my fastboot and adb .exe, i think an old version?
I now downloaded from here http://forum.xda-developers.com/showthread.php?t=2588979
And these are working!

So if someone ever have problems command doesn't recognize fastboot commands, its not always the driver! It can also be the fastboot.exe
This transformer is working again !

lj50036 · Aug 21, 2014

lvrijn said:
Thanks for the advice.
It was not the driver, if was my fastboot and adb .exe, i think an old version?
I now downloaded from here http://forum.xda-developers.com/showthread.php?t=2588979
And these are working!

So if someone ever have problems command doesn't recognize fastboot commands, its not always the driver! It can also be the fastboot.exe
This transformer is working again !

Great to see you up and running...:good:

I did add a Troubleshooting post number 3

The Josh

lj50036 · Aug 21, 2014 at 10:02 AM

berndblb said:
Great stuff! Thanks for this thread Josh!

Now , if I understand this correctly, the insmod command injects a command into the kernel to boot straight to the bootloader before checking misc to break that 'forced reboot to recovery' cycle.
Kinda correct?

In another thread @_that stated once that

Code:

fastboot getvar all

does not return misc as a supported partiton and that

Code:

fastboot erase misc

only "theoretically" erases misc partition. Is that confirmed now?

You guys are great! So much fun to learn this...

No, I dont think it injects anything into the kernel as there may not even be one in the LNX partition ..

The bootit.ko module comes from the source of the kernel code..

Also the /misc partition is a full partition as shown here ..

Code:

mmcblk0p3
Offset: 1292369920 (0x4d080000)
Size: 2097152 (0x200000)
File system size: 512 * 4096 = 2097152 (fully occupies partition)
Linux rev 1.0 ext3 filesystem
Not mounted
Permissions: GID system can manipulate
Contains: Empty file system
Purpose: Recovery /misc
Referenced by: /system/lib/libandroid_runtime.so recovery ramdisk: /etc/recovery.fstab
Note: File system is referenced in recovery as emmc, not ext3!

Thx Josh

_that · Aug 22, 2014 at 7:32 AM

lj50036 said:
No, I dont think it injects anything into the kernel as there may not even be one in the LNX partition ..

I think berndblb meant that insmod injects something into the *currently running* kernel, which it does. It's used for loading additional kernel modules, usually drivers. When a module is loaded, its "init" function is called by the kernel so that it can hook its functionality into the proper kernel subsystems. My bootit.ko's init function simply reboots the tablet - without properly terminating processes, unmounting filesystems, etc. - so it should only be loaded when no partitions are mounted.

lj50036 · Aug 22, 2014 at 1:13 PM

_that said:
I think berndblb meant that insmod injects something into the *currently running* kernel, which it does. It's used for loading additional kernel modules, usually drivers. When a module is loaded, its "init" function is called by the kernel so that it can hook its functionality into the proper kernel subsystems. My bootit.ko's init function simply reboots the tablet - without properly terminating processes, unmounting filesystems, etc. - so it should only be loaded when no partitions are mounted.

Nothing like _that to put you in your place....

awilson77584 · Sep 10, 2014 at 1:54 AM

lj50036 said:
Nothing like _that to put you in your place....

I'm trying to get back to a working recovery. Now I get a cycle of TWRP splash screens. This method looks promising because it appears to rebuild all of the partitions. I can use the Vol Down + Power keys to get to the bootloader (us_epad-10.6.1.14.10-20130801 A03. Can I skip to the fastboot steps? I had Crombi-kk running with rom2sd before I broke something trying to upgrade to zombie-x.

Thanks!

LetMeKnow · Sep 10, 2014 at 2:07 AM

awilson77584 said:
I'm trying to get back to a working recovery. Now I get a cycle of TWRP splash screens. This method looks promising because it appears to rebuild all of the partitions. I can use the Vol Down + Power keys to get to the bootloader (us_epad-10.6.1.14.10-20130801 A03. Can I skip to the fastboot steps? I had Crombi-kk running with rom2sd before I broke something trying to upgrade to zombie-x.

Thanks!

You can skip all the way down to the command "fastboot erase misc". It should kick you out of twrp cycling...good luck..:fingers-crossed:

awilson77584 · Sep 10, 2014 at 2:50 AM

LetMeKnow said:
You can skip all the way down to the command "fastboot erase misc". It should kick you out of twrp cycling...good luck..:fingers-crossed:

Thx!

awilson77584 · Sep 10, 2014 at 3:57 AM

Back up and running! Thanks!!!

[GUIDE][BRICKED] [BOOTS ONLY TO RECOVERY][All ASUS TRANFORMERS]

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