[ROM][03/06/2011]FlashBack21 v2 -Return to Factory Stock - March 2011 OTA

[SIZE=+3]FlashBack21 v2 - Return to Factory 2.1 Stock - March 2011 OTA[/SIZE]

Note1: This ROM supersedes the (former) "FlashBack15" ROM as of 2010/10/20. This step was taken because it appears that VZW/Google are no longer providing Cupcake->Eclair OTA downloads for the Eris.

Note2: The V2 FlashBack21 ROM installs the stock HTC software corresponding to the March 2011 OTA version V2.41.605.6. The V1 FlashBack21 ROM installs the stock HTC software corresponding to the July 2010 OTA - version V2.37.605.4


[SIZE=+2]Last Updated: March 06 2011[/SIZE]

This ROM is intended for reverting a rooted Eris with a custom recovery to the HTC stock software: March 2011 2.1 OTA ROM - v 2.41.605.6. There are many other ways to do this; but this way uses Amon_RA for the installation as a convenience for less experienced rooters. (And only Amon_RA v1.6.2 - the installer will refuse to work with any other recovery.)

Two versions are provided: one which flashes the radio firmware version 2.42.01.04.27, and one which does not flash the radio; other than this difference, they are identical. (The same radio firmware - v2.42.01.04.27 - was used in both the July 2010 & March 2011 OTA releases.) Choose the ROM which best fits your needs. If you already have the most recent radio installed (2.42.01.04.27), there is no need to reflash the radio.

File name: "FlashBack21_v2.zip" (download link and md5 sigs below).
File name: "FlashBack21_v2_noRadioFlash.zip" (download link and md5 sigs below).

Derived from the Eris "March 2011 OTA" (2.41.605.6) release, this ROM repackages the last official 2.1 ("Eclair") release for the Eris from HTC/VZW so that it can be installed with Amon_RA recovery - you flash it just like any other dev ROM. There are essentially no customizations, and no built-in root or extra tools; it is 99.99% stock, with the following difference:


- This ROM also performs jcase's "Flash Any RUU" patch to the misc partition during the flashing process.

This step is performed so that the Eris responds well to flashing operations involving the use of any PB00IMG.zip file (via HBOOT), or application of any RUU utility for the Eris. So, even though this is an "unrooting" ROM, pains are taken to make sure that it is easy as possible to re-root or manipulate with existing methods.

This ROM does not touch the bootloader (or "Hboot" or "IPL/SPL"). If you want to install a different bootloader, do it first before applying this ROM.


[SIZE=+1]Please Note: THE RECOVERY BOOT PARTITION IS REPLACED BY THE MATCHING VERSION OF THE STOCK RECOVERY PARTITION (V2: March 2011 OTA; V1: July 2010 OTA) in this ROM. This means that you will need to re-root your phone if you use this ROM, should you later decide that you want to restore a different ROM.[/SIZE]

[SIZE=+1]Please Note 2: ONE OF THESE ROMs FLASHES A RADIO. This is different than nearly 99% of all Eris dev ROMs. You will see some activity at the conclusion of your Amon_RA recovery session as a result of this - if you choose to use the ROM version that flashes the radio firmware.[/SIZE]



[SIZE=+2]Instructions[/SIZE]

- Read this whole post all the way through before you begin
- Charge your phone completely
- Download the .zip file you need to the top-most folder of your SD card
- Verify the length and/or MD5 checksums (of the copy of the ROM file on the SD card)
- Boot into the Amon_RA recovery, Wipe, and then flash the FlashBack21 ROM (of your choosing)

IF YOU ARE FLASHING THE RADIO:
- When flashing is complete, you will see the message at the bottom of the screen:
"Reboot via vol-up+vol-down or menu to complete installation"
- Make sure to exit Amon_RA after the ROM has finished flashing by selecting the "Reboot now" top-level menu item. Don't do something stupid like pulling the battery.
- You will see two successive splash screens that you do not normally see when using Amon_RA - these indicate that the factory recovery boot is performing the radio flashing operation. Do not interrupt - the phone will reboot on it is own when this step completes.


[SIZE=+2]Acknowledgments[/SIZE]

- Amon_RA for his recovery boot
- jcase for his disclosure to the Eris community of the misc partition "main version number" patch
- hundreds of others on XDA and AF too numerous to mention
- doogald for re-hosting the ROMs (2/15/2012)


[SIZE=+2]Downloads - V2 - March 2011 OTA - v 2.41.605.6[/SIZE]
(Thanks to XDA user doogald for hosting these downloads!)


[SIZE=+1]Flashes Radio !!!![/SIZE]
FlashBack21_v2.zip ( 109,245,758 Bytes; MD5: 3c770473e18e539afe5d090b4a5462ca )

[SIZE=+1]Same ROM, but does NOT flash Radio[/SIZE]
FlashBack21_v2_noRadioFlash.zip ( 102,181,672 Bytes; MD5: d0137efb10dd714cf3770e5ff7b842f5 )



[SIZE=+2]Downloads - V1 - July 2010 OTA - v 2.37.605.4[/SIZE]
(Thanks to XDA user doogald for hosting these downloads!)


[SIZE=+1]Flashes Radio !!!![/SIZE]
FlashBack21_v1.zip ( 108,784,952 Bytes; MD5: 416a92afe52d87beccbef29380a2009f )

[SIZE=+1]Same ROM, but does NOT flash Radio[/SIZE]
FlashBack21_v1_noRadioFlash.zip ( 108,784,967 Bytes; MD5: 44bff966290bb02c0b70ae06ef95d719 )

(Note that both V1 ROM files include the radio image, even though the latter does not flash this firmware - that is why the file sizes are nearly identical.)



OBSOLETE & DEPRECATED - Flashback15_v1
Thanks to XDA user doogald for hosting this download!

- This is here for historical purposes only.
- Note this now ONLY provides a Cupcake (Android 1.5) Factory roll-back for the Eris, as VZW/Google are no longer providing OTAs for the Eris.
- Do not use unless you specifically want a stock "Cupcake" (Android 1.5) Eris
- Note this ROM also UNROOTS YOUR PHONE by replacing the custom recovery with the stock recovery

FlashBack15_v1.zip ( 94,011,341 Bytes; MD5: e5e7ab9f3bc3314f28543fd88ae296fd )


bftb0

TopazAaron said:

ill be using this in the next few days, got to return my eris cuz trackball is going out :/

Click to expand...

Click to collapse

Note that this ROM does not replace the bootloader - so, if you have the engineering bootloader on your phone, you might just want to flash the MR2 RUU (or the corresponding PB00IMG.zip) immediately after booting this (no point in doing the OTA twice). Or, for folks that know their way around fastboot, if they have the S-OFF bootloader, there is always the option to put an S-ON bootloader back onto the phone thusly[SIZE=+1]**[/SIZE]:


I did things this way (no replacement of the bootloader) because most of the folks that did their Eris rooting the "old school" way - and have the Engineering bootloader on their phone (1.49.2000 S-OFF) are comfortable using adb or fastboot, et cetera - and probably have enough knowledge to manually replace their bootloader; whereas the late-comers to the rooting party (leakers and others) that are not familiar with these methods probably used "one click" or similar, so they probably don't have the S-OFF bootloader on their phone anyway.


If I was going to return a phone to VZW, and was concerned that a computer forensics expert was going to examine my phone (I'm 99.999% confident that this does NOT happen), I would apply the MR2 and then take the OTA after that.

Here are the reasons why (these are really only motivations for the ultra-paranoid):

- None of the dev ROMs have ever touched the "NVRAM" area of the phone, whereas the "leak" PB00IMG.zip ROMs did manipulate that. So, phones that went through a leak-flash install still have evidence (in NVRAM) that they have been flashed with unofficial software releases (from HTC), even if the so-called "ROM" has been replaced. The only way to over-write that is to re-write the NVRAM using a VZW-sponsored RUU (or corresponding PB00IMG.zip file). In my mind, that is the MR2, not the "Official" ( == Leak-V3) RUU.

- The same thing is true of the "misc" partition - evidence of fooling around with HBOOT+PB00IMG.zip files persists in the misc partition if you do not take steps to overwrite it. (I flashed and rooted my phone an absurd number of times yesterday (for testing), and right now my misc partition reports "2.19.605.1" because the last thing that I did was install the S-OFF bootloader using HBOOT and the battery-pull trick).

- Forensic evidence in the form of directory or file timestamps probably can determine if a phone has a non-factory, or non-RUU software on it. The same thing is probably true of very low-level (yaffs2) filesystem storage order - there is no reason to believe that the file storage order (relative to the linear page layout of flash memory) will be preserved with a non-stock installer.

But, as I said, the above considerations are for the truly paranoid. VZW doesn't look at phones that carefully, and probably can not for economic reasons - and all the things I mentioned above can not be determined easily (for instance by a retail clerk looking at the booted phone)

But in a way, it doesn't matter anyway - because of the "checkin" process that happens every time the phone boots up, and the pattern of phone activations or market history, Google and VZW have enough information available (between them) in the form of user activity that they could identify every rooted Android user on the VZW network - if they cared enough to do so.


As I said, if I were going to return a phone, I would do the "misc" partition hack, install the MR2 RUU (or matching PB00IMG.zip file), and then take the OTA - and then finally perform a factory reset. But even that is probably far more effort than is necessary.

bftb0


[SIZE=+1]**[/SIZE] Flashing the bootloader is the single most dangerous operation you can perform. Make damn sure the file you are planning on flashing has the correct MD5 signature, as "fastboot" does not check a single thing - it will allow you to flash total garbage to the phone.

eriscentro said:

I'm shipping back an Eris which I used this method on to remove root, but don't have time to do the 2. 1 update, do you think VZW cares that its running 1. 5?

Click to expand...

Click to collapse

Doubt it matters. It takes about 20 minutes for the full OTA 2.1 update, but once you kick it off, the entire process requires no interaction - go do something else for 20 minutes.

You might also want to do a factory reset using the the phone's menu - that will clear the activation status of the phone.

NPH- said:

ok... I read bftb0's post... but not sure I'm following

I did the universal one click root method to root my phone and I'm not sure if I need to go to the trouble of flashing something to fix the bootloader or w/e...(not sure if I even messed with the bootloader, maybe I did but this is the noob coming out in me)

If I wanted to send my eris back today to verizon, wouldn't flashing this new zip fix everything I need it to fix and make it comepletely back to its original stock settings??

Click to expand...

Click to collapse

You will be fine. The radio gets flashed by the 2.1 OTA, and you never replaced your bootloader with the one-click method, so that is already stock.

If it happens that you were one of the "leakers", then you have the 1.49.0000 S-ON bootloader, and VZW has shipped phones with that, too.

Be happy.

bftb0