[Motorola Droid RAZR] hochsaler:
"Convert" Japanese IS12M (XT909) into XT910

Here I describe a method how I rescued my Japanese IS12M (XT909) after bricking it. Probably this method is also suitable to overcome the limitations and restrictions which IS12M has in general.

First a few statements. I bought my IS12M brandnew in Japan from network provider kiddi/au in Japan. The original firmware seemed not to access the SIM card at all since au uses a kind of subscription within their CDMA network. At least I was not able to use this phone in other parts of the world although the spec says it supports GSM as well. It also didn't change much after flashing a radio firmware from XT912 (CDMA version of Verizon in the US) when I followed some instructions found on a Japanese website. In fact I was able to receive messages after that - but never to send any. :( At least I rooted the phone and removed some apps from the provider. But since I was new to this I didn't have any backup and I was never able to find the original ROM for download.

I installed also BMM and later safestrap successfully to try ROMs in other slots. Since IS12M is a CDMA phone I tried several ROMs for XT912 and they seemed to work quite well. Because I was so unhappy with the stock ROM I decided recently to try to replace it - and that's how I bricked my phone. It turned out that IS12M and XT912 are not that compatible as it seemed to me. Flashing stopped somewhere and after that the phone didn't boot anymore, just black screen. At least I was able to boot into fastboot.

But recently I had luck and found a suitable ROM in a Chinese forum. It was not able to understand all but because of the file name it seems to be made especially for IS12M. After I flashed it with RSD Lite my phone booted perfectly - but now it indicates XT910! The revision information was similar to the one from post #1 here, just a few minor revisions lower. Therefore I replaced the file system.img in the file of the link in post #1 and now it indicates exactly the same revisions, except baseband revision of course since this file includes the CDMA radio.

Step 1: make a folder, download and extract this modified file to it:

http://www.mediafire.com/download/a7b7owm7ydcgwcu/fastboot-p2b_spyder-cdma_spyder-user-4.1.2-6.7.2_GC-404-430-release-keys-ChinaRetail-CN_chn.zip

Step 2: put your IS12M into fastboot mode

Step 3: open the XML file and flash it with RSD Lite. Short Note: in post #1 it is recommended to not flash cdt.bin. I flashed all sections completely and didn't experience any issues. Since I am not an expert I don't know if it might be better to follow the recommendation?

After these steps the phone should boot and the basic functions should work. Since this is a Chinese ROM it comes without all the google stuff. Therefore you might want to add a few more things.

Step 4: Rooting, installation of BMM and SuperSU corresponds to step 4 of post #1. However, with the boot.img that was included by Senseddin, the author of post #1, my phone didn't boot. Therefore I replaced boot.img once more by the original one from the Chinese IS12M ROM. The script also wants to reboot into BP Tools twice. As far as I remember I didn't do that, just booted normally and pressed Enter. I updated and renamed the file. Download:

http://www.mediafire.com/download/x9j7otnqdg11o9i/MotoMod_IS12M_CN404_rootscript.zip

Note: I used only the linux script in ubuntu. I updated also the Windows batch file but this is untested!

Step 5: Installation of gapps package. For download link and instructions please refer to post #1.

After successful installation the phone should be fully operable and on the latest revision. Revisions are the same as in screenshots in post #1 with one exception: baseband revision for CDMA should be N_05.11.01P.

So far I didn't experience any issues, I can make and receive calls, send and receive messages, install apps (for instance I replaced BMM with safestrap, because I had the impression that BMM caused some problems when booting). There is no lag, the phone is very responsive and I am quite happy.

One funny thing: when connecting to a PC it still reports "IS12M" - but I don't care...