OK so we know the bionics bootstrap recovery doesn't work. I was messing around with Rom manager and flashed the bionics recovery and was successful. Recovery version 5.0.2.5. Then I booted into recovery from Rom manager and performed a successful backup! Gonna hold out on flashing the backup right now but I'm hoping someone that knows a lot more then me will look into this also and see what they think about it and can we possibly use everything without fearing a bricked device .
i successfully created a backup using the bionic bootstrap recovery, but im leery of trying to do a restore without having an sbf handy
Well I got brave and clicked the restore button using the bionic bootstrap recovery. I have 20+ days left to return the phone if anything went wrong. I backed up using the recovery, then clicked restore. Everything restored perfectly. I did not choose wipe data though, as I didn't think it would matter. Just thought I would add that bit of information. Hope this helps guys.
Sent from my MB865 using XDA App
I just used CWM 5.0.2.5 to restore the system backup I made before updating, and indeed it worked fine. I'm back down to 55.11.16 android 2.3.5 (from 55.13.16 - 2.3.6) with seemingly no ill effects. IIRC, I made this system image with the bionic bootstrap recovery app.
Im still on 55.11.16 android 2.3.5 also, I know using Rom manager to make a backup took a lot longer then what I was used to on my OG. Just went through a restore with no seemingly ill effects. Has anyone tried flashing a zip yet? Just glad we seemingly have a recovery that is working.
my vivid will be here in the next day or 2. once i have that, i will risk the Atrix2 and start working on a rom.
Oh no Pirate your switching over to the HTC Vivid? I have been looking at the reviews on that device and it looks as thick as my A2 with the defender otterbox. I'm going to kick my cat if people start abandoning ship on the A2, bummer!
Awesome work on getting CWM to backup and restore. I would love to see some custom roms being dumped onto this device.
Nice! Recovery loads up smoothly on rom manager. This could get interesting...
If your bootloader is not unlocked be very careful as to what you flash!
Try a theme or something that does not affect kernals,
Just my thoughts
sent from my Atrix via XDA premium
Pirateghost said:
my vivid will be here in the next day or 2. once i have that, i will risk the Atrix2 and start working on a rom.
Click to expand...
Click to collapse
I still have 20 days to be a guinea pig LoL
If you really feel like being a ginuea pig you should try flashing the zip from this thread. It's a few posts down.
http://forum.xda-developers.com/showthread.php?t=1331644
sent from my Atrix via XDA premium
marko! said:
If you really feel like being a ginuea pig you should try flashing the zip from this thread. It's a few posts down.
http://forum.xda-developers.com/showthread.php?t=1331644
sent from my Atrix via XDA premium
Click to expand...
Click to collapse
i wouldnt. i havent even modified the updater-script to be right yet....
hell, i made it, and even i wouldnt flash it in that state
I dont see any zip in that thread? Are you referring to the system.img.zip pirateghost posted? That was in the recovery thread?
Pirateghost said:
i wouldnt. i havent even modified the updater-script to be right yet....
hell, i made it, and even i wouldnt flash it in that state
Click to expand...
Click to collapse
Thanks for the heads up!!
I'm unable to reapply the patch up to 55.13.15
Code:
contents of partition "boot" didn't match MTD:boot:8388608:9651a551679347926bb7589bb4b57d8dea357cb4:8388608:b56beaeb976b10b86cdbd38e87024ab16fe1197f
I've supposedly restored the boot partition with cwm, oh well.
This is probably to be expected. I'm guessing I can only get the stock boot partition back with a proper fxz flash to stock...
edit: I don't think cwm is even saving a boot image. I don't see one in any of my backups.
Makes me wonder what it's doing when I restore boot
JRW 28 said:
I dont see any zip in that thread? Are you referring to the system.img.zip pirateghost posted? That was in the recovery thread?
Click to expand...
Click to collapse
he was talking about this post:
http://forum.xda-developers.com/showpost.php?p=19033826&postcount=7
Just because I'm willing to try things doesn't mean I'm willing to knowingly brick my phone.
Thanks PG!!
Oddly enough it was the Bionic recovery installed from Mod Manager is what I had installed when I bricked my phone.
Pirateghost said:
i wouldnt. i havent even modified the updater-script to be right yet....
hell, i made it, and even i wouldnt flash it in that state
Click to expand...
Click to collapse
well thhats good to know !
does any flashing work with cwm? ie flash files to system? i can see nandroid not working, but simple flashing should.
svtfmook said:
does any flashing work with cwm? ie flash files to system? i can see nandroid not working, but simple flashing should.
Click to expand...
Click to collapse
No. I built several zip files to flash and cwm nor the bionic bootstrap worked.
I think we may have to wait for the official cwm release, with our device in it.
Jim
Sent from my MB865 using XDA App
Related
I know about nvflash but it seems rather risky and complicated, is there a way to just flash a .zip from cwm to get stock recovery?
Sent from my Incredible using XDA App
Crimton said:
I know about nvflash but it seems rather risky and complicated, is there a way to just flash a .zip from cwm to get stock recovery?
Sent from my Incredible using XDA App
Click to expand...
Click to collapse
I hope so, that is why I immediately did a backup of the original rom as soon as I installed Clockworksmod.
jfholijr said:
I hope so, that is why I immediately did a backup of the original rom as soon as I installed Clockworksmod.
Click to expand...
Click to collapse
hope so see that soon
Flash to vanilla stock - see the FAQ area (in my sig) for links.
I flashed the lasted stock via clockworkmod and it actually flashed recovery, as well. So it should get you to a 100% vanilla setup.
Hey guys..
I just today rooted my lovely Nexus S, 9023 or what its called (non branded or nothing)
But i cant load recovery.. went fine when i rooted it, but now that i want to load an custom rom it fails.. i followed this guide to root: http://forum.xda-developers.com/showthread.php?t=883032
Anyone have some ideas??
I just get a android logo and triangle + ! in it.. as error.. (
Best regrads
n0ta
Just tested with ROM Mananger, it can backup just fine.. as soon i choose a ROM to install it loads recovery and fails, just like when you do it manually.
n0ta said:
Just tested with ROM Mananger, it can backup just fine.. as soon i choose a ROM to install it loads recovery and fails, just like when you do it manually.
Click to expand...
Click to collapse
Sounds like stock recovery installed itself. If you are rooted remove/rename /etc/install-recovery.sh then reflash cwm manually or through rom manager.
Sent from my Nexus S 4G using XDA Premium App
I have had this happen on my NS4G. I know they are a little different, but it seems like you are having the same thing happen that I did and to solve it, I open Windows command prompt(or terminal depending on you OS) and fastboot flash recovery (insert recovery.img name here) and reflashed the recovery partition with clockwork. Very easy fix. Just make sure you boot straight into recovery after flashing and flash the Rom you want to flash before booting back into stock(also make a nandroid before that). After that you shouldn't have any more problems unless you unroot. There must be a small glitch somewhere when flashing the clockwork doesn't fully erase stock recovery partition.
krohnjw said:
Sounds like stock recovery installed itself. If you are rooted remove/rename /etc/install-recovery.sh then reflash cwm manually or through rom manager.
Sent from my Nexus S 4G using XDA Premium App
Click to expand...
Click to collapse
Works now thanks all to both of you.
n0ta said:
Works now thanks all to both of you.
Click to expand...
Click to collapse
Pretty common lately...Android for Nexus S recovers its recovery if it is changes...
"You dawg, we heard you like recovering your recoveries, so we made recovery recover in recovery." and all that...
bender_123 said:
Pretty common lately...Android for Nexus S recovers its recovery if it is changes...
"You dawg, we heard you like recovering your recoveries, so we made recovery recover in recovery." and all that...
Click to expand...
Click to collapse
The Nexus one did the same thing. Most OTAs verify / replace this file. It's easy enough to deal with if you're unlocked and rooted.
Sent from my Nexus S 4G using XDA Premium App
This is about the third or fourth time this question has come up over the past week...
bender_123 said:
This is about the third or fourth time this question has come up over the past week...
Click to expand...
Click to collapse
I assure you it won't be the last.
Sent from my Nexus S 4G using XDA Premium App
Whenever i try to flash a new ROM it doesn't want to load. I've tried the CM7 nightlies and the pheonix ROM. This is what I do.
I root my phone via one click root.
Install clockwork recovery via app.
wipe
install ROM via recovery (install zip)
start up
Locks at LG screen. Ugh!
Any advice?
Turague said:
Whenever i try to flash a new ROM it doesn't want to load. I've tried the CM7 nightlies and the pheonix ROM. This is what I do.
I root my phone via one click root.
Install clockwork recovery via app.
wipe
install ROM via recovery (install zip)
start up
Locks at LG screen. Ugh!
Any advice?
Click to expand...
Click to collapse
What OS are you coming from?
Wipe cache
Wipe dalvik cache
Wipe data
Wipe system
Flash.
NVIDIA NEVER AGAIN!
Turague said:
Install clockwork recovery via app.
Click to expand...
Click to collapse
NO, NO, NO! It's one thing to do this, alot have, it's another to not read threads or research it.
NEVER flash CWM from an app, you HAVE TO flash via NVflash.
http://forum.xda-developers.com/showthread.php?t=1054492
Волк said:
NO, NO, NO! It's one thing to do this, alot have, it's another to not read threads or research it.
NEVER flash CWM from an app, you HAVE TO flash via NVflash.
http://forum.xda-developers.com/showthread.php?t=1054492
Click to expand...
Click to collapse
Why? What happens if you did from the ROM Manager? Sorry im a noob to this device
Sent from my LG-P999 using XDA App
Волк said:
NO, NO, NO! It's one thing to do this, alot have, it's another to not read threads or research it.
NEVER flash CWM from an app, you HAVE TO flash via NVflash.
http://forum.xda-developers.com/showthread.php?t=1054492
Click to expand...
Click to collapse
This is a must for the g2x. If you use from manager it only fake flashes clockwork mod recovery and makes you unable to flash roms.
Typical way to achieve root on the g2x is to.
1. Nvflash cwm
2. Create a nandroid backup.
3. Flash a rom that has root.
Don't bother with rom manager or super one click.
Sent from my Galaxy Nexus using xda premium
Just as a quick question. Does wiping the system, wipe ANY of my data? Like does it only wipe the existing ROM? Ive been confused of it since the first time i flashed a ROM
Sent from my G2X
Волк said:
NO, NO, NO! It's one thing to do this, alot have, it's another to not read threads or research it.
NEVER flash CWM from an app, you HAVE TO flash via NVflash.
http://forum.xda-developers.com/showthread.php?t=1054492
Click to expand...
Click to collapse
Thanks, I'll give it a shot and get back to you. I don't think it had to do with the wipe as I always ran a wipe script before installing. I thought it had to do with the kernel.... (don't have a clue though)
I'll flash the clockwork via nvflash, and get back to you, thanks.
EDIT:
IT WORKS. NVFlash the recovery, make sure to change the command if you have a different version you plan to flash/
I used rom manager and all, my roms have worked fine... :S
Sent from my LG-P999 using XDA App
theNOOBuser said:
I used rom manager and all, my roms have worked fine... :S
Sent from my LG-P999 using XDA App
Click to expand...
Click to collapse
You sir are a very lucky man.
Lol. I'm guessing it was a noob-move getting clockwork through ROM Manager. Ill probably use nvflash when I get home just to be safe hahaha
Sent from my LG-P999 using XDA App
theNOOBuser said:
Lol. I'm guessing it was a noob-move getting clockwork through ROM Manager. Ill probably use nvflash when I get home just to be safe hahaha
Sent from my LG-P999 using XDA App
Click to expand...
Click to collapse
you definitely want to do that. do you have a nandoid backup of your original system? if your phone breaks, that is the only way to revert it back to original for an exchange (unless ofcourse you take a hammer to it).
Yeah. I have a Stock froyo backup.
Sent from my LG-P999 using XDA App
jblah said:
you definitely want to do that. do you have a nandoid backup of your original system? if your phone breaks, that is the only way to revert it back to original for an exchange (unless ofcourse you take a hammer to it).
Click to expand...
Click to collapse
i first flased cwm using nvflas... but then i updated it thru rom manager ... is it ok?
rohitmohanihm said:
i first flased cwm using nvflas... but then i updated it thru rom manager ... is it ok?
Click to expand...
Click to collapse
I think so. Catch is that I don't know if doing that will actually update anything, the whole problem is that ROM manager doesn't flash it properly/to the right place. The only thing to do is make a nandroid and try it out and if ti doesn't work, then reflash with NV flash and you're good.
Волк said:
I think so. Catch is that I don't know if doing that will actually update anything, the whole problem is that ROM manager doesn't flash it properly/to the right place. The only thing to do is make a nandroid and try it out and if ti doesn't work, then reflash with NV flash and you're good.
Click to expand...
Click to collapse
I flashed a few other ROMs after i updated CWM thru ROM manager.. and all of them flashed with out any problems.. the only Issue i had was when i tried flashing Morfic's Trinity kernal .. my phone would get stuck at the boot animation.. i wiped every thing and reflashed CyanogenMod and my phone is working agin [I wiped cache and Dalviks before i flashed the kernal.. i guess my phone cant handle it] http://media.xda-developers.com/images/smilies/mad.gif .. Thanks Bro
Ok just got this phone and have decided to go with Phoenix Blood rom, but how do i start? I have to be on froyo to root? Im coming from samsung epic on sprint that i flashed so im not completely retarded. Thanks for any help
Use superoneclick to root on froyo.
If your on 2.3.3 gb there's a flashable. Zip in development section to root.
Also you will want to use tgagunnmans nvflash method to install clockworkmod recovery in dev section.
Phoenix blood is a great choice btw, enjoy!
Sent from my LG-P999 using xda premium
You're still on Froyo? To my understanding it's a good idea to flash the OTA GB first so that you'll get the up to date baseband. Once that's done just go ahead and flash PB.
no im on gb jsut thought i had to go back to froyo to root, so i just flash clockwork mod then pb and thats it?
reeshmd23 said:
no im on gb jsut thought i had to go back to froyo to root, so i just flash clockwork mod then pb and thats it?
Click to expand...
Click to collapse
Yes, but make sure you're using NVFlash to get CWM. Don't use Rom Manager.
Easiest way is using the tool unlockroot. It supports gb on the G2X. Or you can use nvflash, whichever you prefer.
Sent from my LG-P999 using XDA App
redmonke255 said:
Easiest way is using the tool unlockroot. It supports gb on the G2X. Or you can use nvflash, whichever you prefer.
Sent from my LG-P999 using XDA App
Click to expand...
Click to collapse
If he wants to change Roms he will still need Nvflash regardless how he gets it rooted.
GTWalling said:
If he wants to change Roms he will still need Nvflash regardless how he gets it rooted.
Click to expand...
Click to collapse
Agree. Nvflash=bullet proof.
what is nvflash?
reeshmd23 said:
what is nvflash?
Click to expand...
Click to collapse
http://forum.xda-developers.com/showthread.php?t=1056847
From that thread:
Flashing the custom recovery using NvFlash is the only way to ensure that in the case your phone will not boot up, you will be able to get into recovery to fix the issue / flash a ROM / restore from nandroid backup. That is what this app will do for you.
If you flashed the ClockworkMod recovery from ROM Manager it does not flash the recovery to your phone, it fake flashed it. The only way you can gain access to ClockworkMod recovery is through ROM Manager at that point. Using this method is the only way to flash recovery so it is persistent and accessible booting to recovery.
If you have already flashed through ROM Manager you can still proceed with this method. Flash Away!
(You can use both ROM Manager CWM and have the nvflashed version working together. You just access either or one at a time, having the nvflashed one means you can boot to CWM. Welcome to Tegra2)
Click to expand...
Click to collapse
Follow the link. This is a must for tegra 2 based phones. It is always better to be safe than sorry and it also allows you to do a ton of other things, such as making backups and flashing roms. Let us know if you need help. The phone is pretty much unbrickable after you do this. It gives you the ability to recover from any major mistake.
Its in the dev thread, it low level flashes clockworkmod recovery to our phones internal memory partition. You need to install apx drivers first in order for the g2x to be nvflashed.
Sent from my LG-P999 using xda premium
thanks for the help guys got it all set up
Just to add in, nvflash allows u to boot into cwm recovery whenever u want and u don't need to be next to a computer. I think that is how it worked for Samsung phones and Odin, where u needed a computer, but haven't used a Samsung phone so I could be wrong. Remember always make a back up of everything and play around with the different roms, not every rom works for everyone
Sent from my LG-P999 using xda premium
Actually Odin is just like nvflash. It is used to put cwm on you phone and to put the stock recovery back on.
Once you have cwm you can flash what ever rom or kernel without the need for root. Just back up your stock unrooted stock rom before flashing anything else.
If you do that you will have your own stock backup with no need of finding it in the forums if you need to go back to stock.
Sent from my LG-P999 using xda premium
simply put, for as long as i can remember all i had to do is make a full backup, it was stored on my sd, then if i made an error somewhere or flashed a rom i did not like, all i had to do was open up old faithful clockwork and do a restore and everything was fine. well the last few revisions of clockwork have screwed me!
if i do a backup, flash a new rom, make any changes etc, when i want to do a restore in clockwork, guess what? NO RESTORE FILES!
the restore data always gets marked and sent to the LOST directory.
what the hell?
anyone know of any GOOD backup and/or recovery software? i have had it with clockwork!
this is the second time i am having to raw dump an sd card then manually convert the binary back to usable files just to recover important files!
cheers,
disco
You can try CW-Enhanced [v1.1b] by Dread 7 , or TWRP 2.3.1.0 touch Recovery .
Can't go wrong with Dread7us' enhanced recovery (the first link in prboy's post above)
bilgerryan said:
Can't go wrong with Dread7us' enhanced recovery (the first link in prboy's post above)
Click to expand...
Click to collapse
i used this for a long time, dread did great on it. now i use twrp and i actually like it, i hated it for a long time but theyve finally got all the details ironed out imo.
-somebody- said:
i used this for a long time, dread did great on it. now i use twrp and i actually like it, i hated it for a long time but theyve finally got all the details ironed out imo.
Click to expand...
Click to collapse
I've never used it. What do you like about it thats better than the other 2 recoveries available?
Chad The Pathfinder said:
I've never used it. What do you like about it thats better than the other 2 recoveries available?
Click to expand...
Click to collapse
I like the touch interface, the way the menus are laid out. Being able to select what to back up and restore (idk if you can do that on clockwork because I haven't used it in ages lol) and queuing multiple zips to flash right after another.
Sent from my PG06100 using xda app-developers app
jesuscash said:
I like the touch interface, the way the menus are laid out. Being able to select what to back up and restore (idk if you can do that on clockwork because I haven't used it in ages lol) and queuing multiple zips to flash right after another.
Sent from my PG06100 using xda app-developers app
Click to expand...
Click to collapse
With CWM you can select what to restore. But you cannot choose multiple zips to flash.
jesuscash said:
I like the touch interface, the way the menus are laid out. Being able to select what to back up and restore (idk if you can do that on clockwork because I haven't used it in ages lol) and queuing multiple zips to flash right after another.
Sent from my PG06100 using xda app-developers app
Click to expand...
Click to collapse
Did they fix the Sense flashing problem? I used v2 and the only way you could flash a Sense ROM was if it was under 215 MB... And believe me there isn't much Sense left @215 MB I only ever got the one to boot one on TWRP and then Dread came out with his and I have never used anything else.
Chad The Pathfinder said:
I've never used it. What do you like about it thats better than the other 2 recoveries available?
Click to expand...
Click to collapse
he cleaned up the code and added in the superwipe feature from another recovery, i wanna say the amon-ra recovery but i cant remember. the superwipe goes up to a x5 wipe of all partitions and makes it easier to wipe before flashing new roms.
or were you asking me about twrp 2.3.1.0?
---------- Post added at 12:04 PM ---------- Previous post was at 12:00 PM ----------
bilgerryan said:
Did they fix the Sense flashing problem? I used v2 and the only way you could flash a Sense ROM was if it was under 215 MB... And believe me there isn't much Sense left @215 MB I only ever got the one to boot one on TWRP and then Dread came out with his and I have never used anything else.
Click to expand...
Click to collapse
yes it works with sense now
-somebody- said:
he cleaned up the code and added in the superwipe feature from another recovery, i wanna say the amon-ra recovery but i cant remember. the superwipe goes up to a x5 wipe of all partitions and makes it easier to wipe before flashing new roms.
or were you asking me about twrp 2.3.1.0?
---------- Post added at 12:04 PM ---------- Previous post was at 12:00 PM ----------
yes it works with sense now
Click to expand...
Click to collapse
I was asking about twrp. I'll give it a try. Thanks.
Chad The Pathfinder said:
I was asking about twrp. I'll give it a try. Thanks.
Click to expand...
Click to collapse
before the touchscreen felt too sensitive and it also wouldnt flash sense roms correctly. they seemed to have ironed all of that out and i think it works good now. not to mention the ability to theme it if you choose to.
-somebody- said:
before the touchscreen felt too sensitive and it also wouldnt flash sense roms correctly. they seemed to have ironed all of that out and i think it works good now. not to mention the ability to theme it if you choose to.
Click to expand...
Click to collapse
I did like the theming, but wasame only able to find like three when I was using it.
Definitely would recommend Enhanced Clockwork Mod. Best recovery by far...
Sent from my SPH-L710 stock_rooted!
I read that CM doesn't officially support any recovery besides CWM. Why is this?
Shifted from the Twilight Zone
disco_y2k said:
simply put, for as long as i can remember all i had to do is make a full backup, it was stored on my sd, then if i made an error somewhere or flashed a rom i did not like, all i had to do was open up old faithful clockwork and do a restore and everything was fine. well the last few revisions of clockwork have screwed me!
if i do a backup, flash a new rom, make any changes etc, when i want to do a restore in clockwork, guess what? NO RESTORE FILES!
the restore data always gets marked and sent to the LOST directory.
what the hell?
anyone know of any GOOD backup and/or recovery software? i have had it with clockwork!
this is the second time i am having to raw dump an sd card then manually convert the binary back to usable files just to recover important files!
cheers,
disco
Click to expand...
Click to collapse
There's also one more recovery that you can try out if you have the chance, its called AmonRA. I can't say anything about it myself because I've never tried it, but you could give it a shot. I can also say that my favorite so far (haven't tried TWRP though, will soon) is dread's CWM enhanced recovery. Its very useful if your phone won't boot up but you can get into recovery as it let's you run terminal commands straight from there, it also has a very useful Superwipe feature which I think all recoveries should try to adopt/include.
Sent from my PG06100 using xda premium
CNexus said:
There's also one more recovery that you can try out if you have the chance, its called AmonRA. I can't say anything about it myself because I've never tried it, but you could give it a shot. I can also say that my favorite so far (haven't tried TWRP though, will soon) is dread's CWM enhanced recovery. Its very useful if your phone won't boot up but you can get into recovery as it let's you run terminal commands straight from there, it also has a very useful Superwipe feature which I think all recoveries should try to adopt/include.
Sent from my PG06100 using xda premium
Click to expand...
Click to collapse
Recovery is device specific and shifters don't have amon-Ra.
Sent from a KangBanged JellyBean
CNexus said:
There's also one more recovery that you can try out if you have the chance, its called AmonRA. I can't say anything about it myself because I've never tried it, but you could give it a shot. I can also say that my favorite so far (haven't tried TWRP though, will soon) is dread's CWM enhanced recovery. Its very useful if your phone won't boot up but you can get into recovery as it let's you run terminal commands straight from there, it also has a very useful Superwipe feature which I think all recoveries should try to adopt/include.
Sent from my PG06100 using xda premium
Click to expand...
Click to collapse
strapped365 said:
Recovery is device specific and shifters don't have amon-Ra.
Sent from a KangBanged JellyBean
Click to expand...
Click to collapse
like strapped said we dont have amon-ra, thats where dread grabbed the code for superwipe from for his modified cwm recovery
thronnos said:
I read that CM doesn't officially support any recovery besides CWM. Why is this?
Shifted from the Twilight Zone
Click to expand...
Click to collapse
Not sure but I don't really like the cm team. They lock you out of a lot of things
Sent from my EVO using Tapatalk 2
-somebody- said:
he cleaned up the code and added in the superwipe feature from another recovery, i wanna say the amon-ra recovery but i cant remember. the superwipe goes up to a x5 wipe of all partitions and makes it easier to wipe before flashing new roms.
Click to expand...
Click to collapse
-somebody- said:
like strapped said we dont have amon-ra, thats where dread grabbed the code for superwipe from for his modified cwm recovery
Click to expand...
Click to collapse
Just to be clear, I wanted to point out the superwipe wasn't added from another recovery, I wrote all that code myself.
Sent from my EVO LTE
Dread 7us said:
Just to be clear, I wanted to point out the superwipe wasn't added from another recovery, I wrote all that code myself.
Sent from my EVO LTE
Click to expand...
Click to collapse
Beast mode
Sent from my myTouch_4G_Slide using Tapatalk 2