[Sprint HTC EVO 4G LTE] 18th.abn:
I give credit to DesignGears for finding this for the HTC One X. So be sure to give him thanks for his find!

SuperCID will allow ruu'ing back and forth from newer to older builds and vice versa.

ADDED- WILL NOT ALLOW FLASHING OF RUU WITH OLDER HBOOT VERSIONS.

Added- great explanation of supercid benefits http://xdaforums.com/showthread.php?t=1548083

Please follow the instructions VERY carefully as any error in the process can and very easily WILL BRICK YOUR DEVICE. I am in no way recommending this procedure and am not responsible for any device damaged from the following guide.

It's not very difficult if you just follow instructions, so don't be discouraged from the warnings, just pay attention:D

Pre-requisites -

Rooted HTC EVO 4g LTE

Pc with working HTC drivers

Adb and general knowledge of use

Fastboot and general knowledge of

use.

USB debugging enabled

A hex editor on your pc for modifying the partition we are going to pull(HxD is free on cnet)

2ND WARNING-

This procedure will be modifying a partition and pushing it back to device. If modified incorrectly it WILL BRICK your device.

Plug device into pc and select charge only on the device

Open up your command prompt and cd to your folder with adb and fastboot.

Type -

adb shell

Su

You should now see

"root@android: #"

Next we are going to take a copy of partition and save to the external sdcard

Type -

dd if=/dev/block/mmcblk0p4 of=/sdcard2/mmcblk0p4

Hit enter, should get a readout of

2+0 records in

2+0 records out

You now have a copy of partition 4 saved on external sd.

Type - exit, then exit again and you should now be in your fastboot/adb dir. In your command prompt. Minimize the window don't close, we'll be right back.

Now mount your phone as disk drive and open your sdcard on your pc. You will see a file on it named mmcblk0p4. Copy and paste a copy to your pc desktop.

Once copied, right click and go to properties, and WRITE DOWN THE SIZE OF THE FILE,

Should be 1,024 bytes.

after we modify the partition the modified one must be IDENTICAL in size or there's 100% chance of brick when push it back to the device.

Now, open the file mmcblk0p4 in your hex editor

Scroll to offset 00000210, you will see

"...SPCS_001XXXX" X's being 4 numbers we arent going to touch.

ANOTHER WARNING-

Here's where you need to be extremely careful,

we are going to change

"SPCS_001" to. "11111111"

best way to do this is highlight ONLY "SPCS_001" then press "1" eight times, so your replacing 8 characters with eight 1's. Now the full line looks like

"...11111111xxxx".

Three dots before the "1" and four numbers after the last "1". Most likely being 9900.

ADDED- Pic of b4 and after hex edit

http://db.tt/ziScPZBl

Now go to >file>save as and name the file mmcblk0p4MOD and save it to desktop.

Open your external sdcard folder again on pc and put a copy of your new mmcblk0p4MOD in there. Right click it, properties and verify it is the same size as the original. Go back and mount phone as charge only.

14th WARNING:

Hope u followed closely, if you made a mistake here's where u brick!

Maximize your command prompt window from earlier and type-

adb shell

Su

You'll be back at the root@android command prompt

Type-

dd if=/sdcard2/mmcblk0p4MOD of=/dev/block/mmcblk0p4

Hit enter and you should get the same readout from before-

2+0 records in

2+0 records out

Your all done, now to confirm you have superCID type exit, then exit again then

Adb reboot bootloader

Once in bootloader type-

Fastboot oem readcid

Readout should say

INFOcid: 11111111

Confirmed, you were successful. You SHOULD now be able to run any ruu a available for the device, enjoy and don't forget to hit THANKS:D

Sorry if all the warnings are annoying but I don't want any "you bricked my phone, help!" Posts:D