yashsingh1/xdaforums huggingface dataset:
[Thinkpad Tablet General] Einwod:
When I tried to take the OTA to Lollipop, it came down OK but when flashing it wiped the system. I've been like this for a while now and only today have had the time to try to solve the matter. It's damned frustrating to say the least.
[Thinkpad Tablet General] :
there are two possible scenarios for your case:

A. lollipop OTA didn't updated the bios, so you are still on the old KitKat bios so try this first:

- power off if it's on (long press Pwr until it goes off), after press and hold VolUp & VolDown, press Pwr button shortly to start the tab (while keeping volume buttons pressed), release Pwr after start buzz, in a few sec after the screen should say "Fastboot starting.." and nothing more will happen (now you can release the volume buttons) it's impossible that you cannot get that message, if it doesn't apper Pwr off and try again, don't go further until

- start IPFT and use the 1050f KitKat stock rom ( kitkat-YT2-1050F_S0198_150422_ROW.7z) to flash (load the flash.xml, remember to check sparse, 500MB etc)

(should the flashing fail post log from IPFT and also some details on the tablet screen)

B. Lollipop OTA managed to upgrade the BIOS

this one after you do A.
[Thinkpad Tablet General] Einwod:
Thought all was going well until 91% then failed. Attached is the log file and a photo of the screen output.
[Thinkpad Tablet General] :
https://anonfiles.com/file/e65803381ee35a898e603e85f3c78ca8

ok, (i do not have lollipop installed so i can only estimate situations) bear with me

download, extract the file provided, go to that PwrOff and do that stuff above to get to the "Fastboot starting..." message

once there input these two commands:

fastboot flash osloader efilinux-user.efi

fastboot boot droidboot.img

and tell me if you get to the ffastboot(droidboot) screen

also you sure your tablet is 1050f?
[Thinkpad Tablet General] Einwod:
Stays on the Fastboot Starting...... screen and yes, it is 1050F.
[Thinkpad Tablet General] :
well i'm out of ideas at this hour, copy the attached file in your rom dir and flash that (i removed the easydata flasshing part, it's bloatware anyways) go to "Fastboot starting...", then flash using the attached file

should that not work try flash-Factory-blank-emmc.xml
[Thinkpad Tablet General] Einwod:
I'll give it a go in a bit. Laptop is doing quite a large Windows update and the tablet is not recognised on this Windows 10 desktop. Will report back soon.

UPDATE: That flashed OK, just waiting on the startup now. Fingers crossed.

Update 1: Still sitting on the Lenovo splash screen. Have been into recovery mode and tried factory reset. Still nothing. At least it's not booting to bios anymore, just need to get into the system.
[Thinkpad Tablet General] :
flash the blank one
[Thinkpad Tablet General] Einwod:
A blank what?
[Thinkpad Tablet General] :
flash-Factory-blank-emmc.xml
[Thinkpad Tablet General] Einwod:
Edited as requested.
[Thinkpad Tablet General] :
use the attached one
[Thinkpad Tablet General] Einwod:
Unfortunately failure at 88%.

Edit as requested
[Thinkpad Tablet General] :
edit: first check and double check that you cannot boot to the fastboot(droidboot) Lollipop menu using these files (download, extract and how to use below) https://www.androidfilehost.com/?fid=24052804347823805

go to the "fastboot starting.." screen, then enter

fastboot flash osloader bootx64.efi

fastboot boot droidboot.img

if you can then after booting in droidboot menu flash lollipop stock rom (the yandex fike sent prev. IPFT flash.xml)

also read this post http://xdaforums.com/showpost.php?p=62060611&postcount=657 edit2: i was browsing the thread and i noticed you have already posted you issue there (well at least now you can flash/boot partially something :) )

i cannot say how good the method is as i didn't tested it but maybe others can give you more info, i'm pretty sure the problem is a bios one, as we flashed the blank mmc rom and we got errors that are very similar to the ones appearing on a wrong Lollipop to KitKat downgrade (ie when the Lollipop bios was still there). the only question is how safely can you flash a bios downgrade over a bios in an unknown state maybe workdowg can give you more details on this one

maybe useful https://anonfiles.com/file/397c41ab0aafc2a6bd206a0583240c6c this one will give you a temporary adb root shell from the fastboot mode (works on kitkat dunno if it works on lollipop) open a command window on your windows, change dir to your kitkat extracted rom dir, get to the "fastboot starting..." message (dnx mode), then input from within (input exactly as below):

fastboot flash osloader efilinux.efi

fastboot boot droidboot.img

(this should get you to the KitKat droidboot/fastboot menu)

now change dir to where you extracted the fastboot2adb files and run the .bat file (needs fastboot&adb exe in the path) if all ok will drop you to a root shell

if you can manage to boot in the temporary adb root shell then we will try a more hard approach... flashing the original kitkat bios as a whole but for this you must tell me if you are able to get that shell (you should)

i really don't know now... needs more investigations (what makes me thinking is that picture you attached and in it the IFWI string contains IA32 and thats the kitkat signature, if on lollipop bios it should be X64, so something is missing) either a bad bios ota uptade from lenovo, or a partially written capsule.

unfortunatelly i don't have lollipop for my 1380f released yet by lenovo so i cannot test variants before i recomend them, if i didn't said before be aware that while the flashing of mmc (what we did so far) will not hard brick your tab (ie even if bricked you will be able to get to the "fastboot starting..." message also known as DNX mode and so we can unbrick by software means) yet flashing the wrong way the bios/capsule CAN hard brick (ie with a wrongly flashed bios you will no longer be able to get in dnx mode and the tab will most likely not even start anymnore so only support will save)

please edit your posts where you pasted logs and delete them (maybe put them as attachment) or we risk of being kicked by workdowg :)
[Thinkpad Tablet General] Einwod:
A heartfelt Thanks to [MENTION=997923]ionioni[/MENTION] for his time and patience in helping me get back to working order. We tried various things and without his help I would have been totally and absolutely lost. Just a few moments ago, with his invaluable help, I have managed to flash back a kitkat ROM and as we speak, the tablet is downloading the update. I will be forever in your debt [MENTION=997923]ionioni[/MENTION] Thanks again. This man is a genius. One very happy wifey here now her tablet is back up and running.
[Thinkpad Tablet General] :
well... thanks for the exaggerations :)

still, if you can finish uploading that vid with the bios downgrade so i can check details on the 1050F

also, after you finish the OTA update to Lollipop can you try the fastboot2adb temporary root shell to see if it's working on Lolli too?

download from here updated in the next post extract and double-click on batch file

will not change/touch anything on your tablet, as everything happens in the ramfs and after reboot youre like before (that's of course if YOU don't run commands while in the shell, coz as root you can run many commands :) )
[Thinkpad Tablet General] Einwod:
The video in the Lenovo folder in my Drive folder. Waiting for the tablet battery to charge up more before applying the OTA. I'll certainly try to help however I can. And it was no exaggeration either. ;)
[Thinkpad Tablet General] :
update: for the temporary root shell test use the attached file (i packed them all in an exe, no longer needs fastboot and adb as they are packed in) just start in DNX mode and run the exe

check next posts for the tmp_root files (attachment removed)
[Thinkpad Tablet General] Einwod:
Installation of update failed TWICE now. When trying to reboot, screen goes blank after the Lenovo splash screen. Going to have to re-flash again!!!!! Think I'll give the update a miss.
[Thinkpad Tablet General] :
are you referring to the OTA update??
[Thinkpad Tablet General] Einwod:
Yes. Fails during the update process and when rebooting, Lenovo splash screen is on for about 5 seconds then screen goes dark. The backlight is still on, but nothing else. Have to hard reboot to start again. No touch or vibration. Weird.
[Thinkpad Tablet General] :
well this is out of my area... i didn't got yet Lollipop OTA so i can test stuff on it... but these days will come

you need to get more details ... however since it works with no issues on kitkat should work in lollipop too

after-flashing configuration etc i pm you with some could-be situations but whoever knows more ... will see

but a simple one comes in mind: have you set your country code after you flashed the KitKat stock rom??? ( type "####6020#" in Contacts and choose your region on your first KitKat boot)

or just stick to KitKat (you're one of the few who are trying to go to Lollipop :) it;s the opposite request in general)

Lenovo for those who do?
[Thinkpad Tablet General] Einwod:
That was the one thing that I did

NOT

do. It came to mind this morning and just now after coming in from work, I did it. The tablet rebooted and I chose the country locale. Rebooted again, downloaded the OTA and BINGO!!!!!!!!!!!! All up and running Lollipop. Thanks again for all your help. I will have to stop trying to do these things late at night when I'm tired.
[Thinkpad Tablet General] :
good job!

now (after you are running Lollipop) can you try and run that temporary root shell (just so i know it works on a Lollipop bios too). the attachment is on post #131 or just scroll uo, it, on this page
[Thinkpad Tablet General] Einwod:
I tried to run the file from DNX mode. The tab switched off and then showed the battery charging. The window showed as per attachment.
[Thinkpad Tablet General] :
what? lol
[Thinkpad Tablet General] lingiegniere:
can't find droidboot

Hi,

following guide I ca:pn't view "droidboot" menu. My 830l has update with lollipop 5.01.

when I try to update firmware, with flastools, tablet restart (auto) and the update fail.

Why?

thanks for your help and excuse for my English
[Thinkpad Tablet General] :
have you succeed in upgrading to lollipop (have you managed to see the lollipop screen on your tab) and having troubles after or you tried to update and failed?

what do you try to flash? it fails on what?

ho bisogno di dettagli, altrimenti non riesco a capire esatto qual e la tua problema.

capisci?
[Thinkpad Tablet General] szaman89:
Did someone tried to successfully downgrade Lollipop to Kitkat on 1050L?
[Thinkpad Tablet General] :
i did it like 20 times in the last 5 days

see, i have this rare disease called lolipotokikatia contracted when as a child i listened to a slackware iso on my cd (old now) player

it manifests by this strange need of messing around a device and then bring-it back to life

i swear i hear at times the little android begging to be left alone (but this could be just my other illness - paranoia (cd) )
[Thinkpad Tablet General] szaman89:
Can I ask you how you did it?
[Thinkpad Tablet General] :
http://xdaforums.com/thinkpad-tablet/general/yoga-tab-2-830-1050-1380-to-kitkat-t3240487
[Thinkpad Tablet General] szaman89:
Thank you very much! I did update on my sister 1050L and she cries now that hates new ui... Does this tutorial complete or you can add something from you?
[Thinkpad Tablet General] :
funny one... i made the tutorial... so yes i added something from me :)
[Thinkpad Tablet General] szaman89:
Funny indeed... ;) I'm such lame in this device so sorry for inconvenience. I will made it with your tutorial. Thanks again!
[Thinkpad Tablet General] lingiegniere:
Hi,

i have a yoga 830l with lollipop (5.01). I tried to change firmware with 830lc (follow the guide find on xda).

In the guide, figure the "Droidboot" but, on my tab, is not present.

However, i tryed to update with new firmware , flash tool start....and the tablet restart....but.....at one moment, tab restart e load LOLLIPOP, flashtool says FAILED.

In the guide, with droidboot during firmware loading the tab not restart.

I ask ...why my tab restart ?

i read somewhere the reason is bios.....really?

Can I reload a .4.4.2 on my tab?

thanks.....
[Thinkpad Tablet General] :
if on Lollipop you cannot flash directly the stock rom KitKat, first you must downgrade the bios. read this (all of it)
[Thinkpad Tablet General] lingiegniere:
i read now, with my litle phone i'm lost in the forum. Thank You . I try with it.

Thank you, you're kind.
[Thinkpad Tablet General] AndroMAN:
Hi workdowg

Great to see such an extensive thread on the lenovo yoga series tablets and all the help its been giving the people. I'm new to Android and I got my lenovo tab recently. I wanted to root it for having obvious advantages over unrooted experience. I've been through your guides and now I am see of help.

I use a Lenovo Yoga Tablet 2 (8inch) model 830LC, running Android Lollipop 5.0.1.

Would u please give me the link or the method to download and install adb/fastboot drivers for my device.

Also, since there are plenty of technical terms involved it gets difficult to follow the rooting guides available. A noob friendly step by step guide would be extremely precious.

Thank you.

---------- Post added at 06:49 PM ---------- Previous post was at 06:31 PM ----------

Hi Andy

Did u get the adb/fastboot drivers for ur tab? I am in a similar problem like yours and would like help finding those drivers for my tablet.
[Thinkpad Tablet General] workdowg:
[MENTION=5557476]AndroMAN[/MENTION] - try this for Windows adb and fastboot: http://xdaforums.com/showthread.php?p=48915118

From my LG-G4, Rooted running Stock 5.1
[Thinkpad Tablet General] AndroMAN:
Hi workdowg,

Huge THANKS man. Successfully rooted my yoga tablet last night. The link you provided was just what I needed. Initially my device was being detected as mtp device, but after installing the adb drivers, I could locate it as as adb composite device under the system manager. It was a cake walk after that. Thank you so much!
[Thinkpad Tablet General] c0bal7:
Hello everyone. I'm really new in this forum (this is actually my first post) and i'm having a bit of trouble with my wifes Lenovo Yoga Tab 2 Pro (1380F).

We bought it 2 months ago and I assumed that I can install Windows 8.1 or Windows 10 on it. I was so wrong..

Long story short, wife will not use the tab until it has Windows.

I tried a method, with what i could access the BIOS. I thought that would be it, and i could boot Windows from an UEFI USB drive (i used Rufus). The USB boot option will not show up on the screen and no way I could install it directly from the USB.

Anyway, I'm stuck at the BIOS and no Boot from USB option is available.

If i wrote this to wrong topic, then I'm sorry and maybe you can move it, where it belongs.

Has anyone got any ideas, how could I install Windows on it ? I

Thanks!

c0balt
[Thinkpad Tablet General] jumpup:
If anyone is interested, I've used a Kernel/CPU app to manipulate the (quite limited) options with the stock Lollipop ROM, some to better performance and battery results. If anyone would like details, I'll post more info
[Thinkpad Tablet General] workdowg:
Sure, post them. I'll stick it in the beginning.

From my LG-G4, Rooted running Stock 5.1
[Thinkpad Tablet General] jumpup:
Awesome, will do.

The recommended tool is Kernel Manager EX. You need to be root, obviously. I'll make some option screenshots.

Also, Greenify. It's a must along with the Xposed plugin. I was able to install LL Xposed with no issues.

At one point, with casual use and wifi enabled, I got 38 hours on a full charge.
[Thinkpad Tablet General] jumpup:
I'm re-running the two most optimal configs I have found. While they're not the luxury of the many insane, custom kernels many ROMs have, the performance difference is very noticeable.

Stock kernel has four governors:

* interactive

* ondemand

* userspace

* performance

And three cache types:

* cfq

* noop

* (last one I forget at the moment)

Each cache type can be set to one of four sizes:

* 256KB

* 512KB

* 1024KB

* 2048KB

Using Kernel Manager EX (root required), the best fit seems to be interactive/ondemand, cfq/noop and 512KB buffer. Fortunately, the app has a Performance and Powersaving preset that alternates between these two scenarios.

I have disabled Lenovo's power management app. I also use Greenify with the Xposed add-on to keep unnecessary background processes at bay.

In one setting, using the device with wifi and BT around 4 hours a day for video streaming and gaming, I didn't go under 10% battery until Day Three. It ended up around 19-21 hours of use (and standby time in between) until the battery died.

Mileage always varies, of course. Make sure you have a solid, full system image backup using the tethered CWM recovery method. A suggested second layer of backup protection is a full user app + system data backup via Titanium Backup. Put them both on a microSD card that you use with your Yoga 2. Forgive me if this sounds rather "duh!". Just want to keep folks safe.

In pushing the limits of the kernel options, I ran into the odd reboot or logjam here and there. I'll throw the most usable config info into the instructions. Nothing created a scenario any worse than manually rebooting and reverting the settings back to the last best config. Kernel Mode EX lets you save config sets as you wish. You can also track battery, load and CPU time stats with the app.
[Thinkpad Tablet General] jumpup:
Adding 830F partition layout

[MENTION=3971563]workdowg[/MENTION] - When did you run this command? While I'm in the midst of my 830F kernel testing, etc., I will grab a copy of its partition layout. I am using Lollipop at the moment
[Thinkpad Tablet General] Alivevil:
Links are broken

Hi.

i'm looking for the latest stock firmware for my 830L but the links seems to be broken by the host.

can you please update or give me the links in another upload center?

Thank's in advance.
[Thinkpad Tablet General] Einwod:
All the links are working here.
[Thinkpad Tablet General] workdowg:
They are 404'ing now... I'll up the 830L first, give it 30-60 minutes
[Thinkpad Tablet General] workdowg:
830L is up
[Thinkpad Tablet General] jumpup:
[MENTION=3971563]workdowg[/MENTION] - Can you add the following URL for a working, flashable BusyBox package?

* BusyBox 1.24.1 stericson ARM/x86 flashable ZIP

http://xdaforums.com/android/software-hacking/tool-flashable-busybox-v1-23-2-stericson-t3219431

Thanks!
[Thinkpad Tablet General] workdowg:
Sure. Added
[Thinkpad Tablet General] workdowg:
Firmware links updated to AFH
[Thinkpad Tablet General] workdowg:
Sorry, I forgot about this... If you get the following I'll convert it to a readable form:

cat /proc/partitions > 830f-partitions.txt
ls -al /dev/block/by-name/ > 830f-partition-names.txt
[Thinkpad Tablet General] jumpup:
Yoga Tablet 2-830F (16GB) Partition Layout

[MENTION=3971563]workdowg[/MENTION] - Here is the 830F (16GB) partition layout. This is under Lenovo's Lollipop stock ROM

major minor	blocks name
179 1 8192 reserved -> /dev/block/mmcblk0p1
179 2 33792 ESP -> /dev/block/mmcblk0p2
179 3 16384 boot -> /dev/block/mmcblk0p3
179 4 20480 recovery -> /dev/block/mmcblk0p4
179 5 16384 fastboot -> /dev/block/mmcblk0p5
179 6 8192 reserved_1 -> /dev/block/mmcblk0p6
179 7 32768 panic -> /dev/block/mmcblk0p7
179 8 524288 factory -> /dev/block/mmcblk0p8
179 9 8192 misc -> /dev/block/mmcblk0p9
179 10 131072 config -> /dev/block/mmcblk0p10
179 11 131072 cache -> /dev/block/mmcblk0p11
179 12 262144 logs -> /dev/block/mmcblk0p12
179 13 2097152 system -> /dev/block/mmcblk0p13
179 14 11969516 data -> /dev/block/mmcblk0p14
[Thinkpad Tablet General] jumpup:
Lenovo Support - Yoga Tablet 2-830F/830L/830LC Hardware Maintenance Manual

https://download.lenovo.com/consume...ablet2_8a_830_f_l_lc_hmm_en_v1.0_20140916.pdf
[Thinkpad Tablet General] Paget96:
Thank you for credits [MENTION=3971563]workdowg[/MENTION] ;)
[Thinkpad Tablet General] Alivevil:
thank's a lot for updating the links.

but the problem is that i can't flash ANY firmware or file.

when i push any file with fastboot or even when i try to flash with flash tool i get the blue error " Certificate validation failed, press any key to return" which appear on my yoga tab2.

there fore the flashing process won't go further and by pressing any key (vol + or -) it goes a little further and then the fastboot connection will cut-off and the tablet shows shell commands which is useless since the default bios does not support any keyboard.

i think it is because of my ESP drive and i think my bootloader is locked.

the thread about unlocking the bootloader didn't worked out for my 830 L.

what should i do?
[Thinkpad Tablet General] workdowg:
Forgot about this also.. My bad.
[Thinkpad Tablet General] workdowg:
The certification failed error happens when you are locked and try to flash an "insecure" kernel. Seeing how you know a little about the ESP does this mean you HAD already unlocked you tablet or at least you are on lollipop? If so you are on the 64bit bootloader (lollipop) so try this thread to get back to kitkat first and then take all the ota's (again?) and then try the unlock .
[Thinkpad Tablet General] :
what Android version is on your tablet now? KitKat or Lollipop?

1. place your tab in dnx mode (from power off press and keep pressed both vol keys, then short press pwr button to start, release pwr when buzzing, wait a few and your screen MUST say "Fastboot starting...", when you get that message you are in DnX mode, repeat from power off until you get it)

2. if on kitkat from a command prompt enter :

fastboot flash osloader efilinux.efi

fastboot boot droidboot.img

or if on lollipop enter :

fastboot flash osloader bootx64.efi

fastboot boot droidboot.img

using the corresponding files from the zip attached

after this in a few seconds a Droidboot menu MUST appear

(you can try both variants if you are not sure about the Android version or if the one tried has not given you the droidboot menu, however you start always from dnx mode)

one of them MUST put you in the droidboot (fastboot) menu, and report back which one so that you can be told what steps you must take further, otherwise (if you still get the certification failed message) something more serious has happened (corrupted bios) and i must ask: have you played with the bios?
[Thinkpad Tablet General] jumpup:
In progress - CWM flashable Lenovo stock images

[MENTION=3971563]workdowg[/MENTION] :

I'm working on converting the Lollipop OTA for my 830F into something that could be flashed from Tethered CWM. I'll share the instructions with everyone so they can do this for their devices as well.

I think the last only requirement might be that folks unlock their bootloader first. Will post findings in the next couple of days.
[Thinkpad Tablet General] workdowg:
I have the actual lollipop firmware if you'd like it.

From my LG-G4, Rooted running Stock 5.1
[Thinkpad Tablet General] jumpup:
Yessir. That'd be awesome. Thanks!
[Thinkpad Tablet General] workdowg:
I won't be home til later...

From my LG-G4, Rooted running Stock 5.1
[Thinkpad Tablet General] jumpup:
No rush at all. It's the weekend :)
[Micromax Canvas 4 A210] Shaan007:
Add your home screen
[P3300, MDA Compact III  upgrading etc.] korky007:
I newest on smartphone mobile

And i don't know what does mean CID lock and how to know if mine is lock or not....

Can someone help me please?
[P3300, MDA Compact III  upgrading etc.] JanetPanic:
The simple answer is that CID lock is the thing that prevents you from flashing a ROM other than one specifically designed for your device. And it is safe to assume that your device is locked unless you unlocked it or had someone unlock it for you.

EDIT: a more thorough explanation can be found here:

http://www.htcwizardweb.net/node/170

NOTE: the unlocking procedure on that page is for the Wizard, not the Artemis. The explanation as to what a CID and SIM lock is can be considered valid for most smartphones/pocketpcs though.
[P3300, MDA Compact III  upgrading etc.] korky007:
I understood but, does exist un soft program can tel me if my phone is lock or not?