[T-Mobile Samsung Galaxy Note II] ciphercodes:
There have been lots of questions about KNOX like upgrading/rooting methods, warranty status etc etc on 4.3 and information is scattered over multiple forums (development, general and questions)

I am creating this thread to cover the following topics or at least to guide you to the right forum. :)

1) What is KNOX ?

2) How KNOX affect us ?

3) How do I verify if Warranty BIT on my phone has tripped ?

4) What trips the KNOX counter ?

5) Is it possible to reset the KNOX counter/Warranty Bit ?

6) KNOX counter has been tripped, now what ? What about warranty ?

7) How to root ?

8) Upgrade options for users on 4.1.2.

9) Thoughts

1) What is KNOX.

Samsung KNOX is a new security feature implemented in Samsung Phones.

You can get more information about KNOX here

2) How KNOX affects us ?

In the latest 4.3 update KNOX has implemeted a secure boot technology that prevents unauthorized boot loaders and kernels from being loaded during the startup process.

So, if you flash this bootloader via (OTA or PC ODIN) then you cannot flash older 4.1.x firmwares.

To further illustrate how this works, the “KNOX Warranty Void” bit (or simply KNOX bit) is used to detect if a non-KNOX kernel has been loaded on the device. It is a one-time programmable bit in e-fuse, which can only be turned from “0” to “1” (i.e. burned). If a non-KNOX boot loader or kernel has been put on the device, KNOX can no longer guarantee the security of the KNOX Container. As a result, this KNOX bit will be burned to “1”, indicating that this device can no longer use the KNOX Container service. There are two possible scenarios: first, a new KNOX Container can no longer be created on such a device; and second, the data encrypted and stored in an existing KNOX Container can no longer be retrieved. Everything else should work just as before.

Reference link

3) How do I verify if Warranty BIT on my phone has tripped ?

You can go in download mode (Home+Volume Down) then power,then on prompt press Volume UP.

If you see KNOX or Warranty Bit set to 0x1 that means the counter has tripped.

4) What trips the KNOX counter ?

Rooting, flashing custom ROMS and kernels trips this counter.

5) Is it possible to reset the KNOX counter/Warranty Bit ?

Not as of now, per Samsung it is impossible as this is a one way process but you never know someone might discover a way to reset it.

6) KNOX counter has been tripped, now what ? What about warranty ?

As of now you cannot revert back to 4.1.x firmwares if you do not like 4.3.

You may or may not have issues with your warranty, it all varies at different service centers.

For those who brought this phone at launch, its over a year and warranty as already expired.

There is an interesting thread here which covers this topic.

7) How to root ?

For those who updated via OTA:

Rooting via CF flashes the KNOX Warranty Counter, further information here

You can flash MrRobinson's (Rooted and KNOX free) ROM but a user reported that flashing this tripped his counter.

Switch to page: 45 and Post# 446.

Make sure you download the v2 ROM. http://www.androidfilehost.com/?fid=23252070760975435

There are few other methods but I do not know much about them so if anyone knows please feel free to post or let me know so I can add it to the OP.

8) Upgrade options for users on 4.1.2.

If you DO NOT CARE about KNOX or warranty just update however you like:

1) Via OTA, if system status is modified or if binary count is not 0: a) Flash Mrrobinsons root 66 b)Use triangle away to reset counter c) full unroot via super user d) factory reset, if this does not work then flash stock via odin after step c. Please note this method will only update to 4.3, you will have to root the phone if you want.

If you DO CARE about warranty status then you can try this method.

1) Flash MrRobinsons v2 ROM via mobile ODIN from here, original thread, Switch to page: 45 and Post# 446.

2) I was able to pack together a stock ROM which is rooted, debloated and includes the 4.1.2(UVMBD1)bootloader.

Link here.

Please note: Mobile Odin does not flash the bootloader, you will still have the updated 4.3 firmware but with an old bootloader, the idea here is to avoid the KNOX bootloader altogether.

WIFI does not work but there is a fix.

To fix WIFI you can either flash the Devil Kernel from here

or

You can flash this WIFI patch compiled by DrKetan. Page 21 post 204.

Special thanks to DrKetan for compiling this patch, MattLowry for working with him to get this done, MrRobinson for stock rooted and KNOX free ROM and DerTeufel1980 for Devil Kernel.

9) It will be awesome if there is a stock ROM with old bootloader, newer system/modem image, root injected, KNOX free and integrated with this wifi patch.

- I was able to pack such ROM but without wifi patch here.

Update: 02/05/2013

Downgrading of ROM's from 4.3 to 4.1.x is possible by flashing the ROM using mobile odin.

4.3 bootloader cannot be downgraded, the work-around is to flash 4.1.x ROMs excluding the older bootloader.

You will end up with a 4.1.x rom on a 4.3 bootloader.

Update: 02/10/2013

User esdwa reported that he successfully rooted his phone using Saferoot method described here.:

Rooting phone via this method does not trip the KNOX counter. Se posts 52 through 55.

Please note: These methods I have listed are the only ones which I know, there might be more options and if you let me know I can add it to the post.