This is the question and the answer on the same post. (I hope I'm posting on the right place)
As you can read from this post and next three pages since, I have problems with persist partition after being formated by accident with CWM
The problem with formating PERSIST partition is that you will kill your wifi. And will not turn on anymore, buttons will look grayed out, etc. There are many threads about, here on XDA.
And of course, you will be unable to re-flash the partition with rsd or fastboot. (Flashing back your original and full stock will not help)
I was pointed to the fix for this accident which is on this post on Atrix HD section. (credit to the guys who helped me)
And thanks to post above I was able to fix my phone´s wifi and bring back to life.
But, after decompress the IMG file of persist partition I saw the WCNSS_qcom_wlan_nv from stock XT925 ROM has only 28 KB. So small compared with Atrix file. On the post fix above you will find the same file but with 1.7 MB
I tested the fix using both. And any file will work. The one from Atrix thread or the one from your own persist partition or the ones here.
You have to copy the file WCNSS_qcom_wlan_nv to the persist partition on home root, aka /persist
(Don't worry if you see an empty folder)
Then. Apply the permissions as follows
Then. Restart. your phone will create the rest of the files and links there.
That's it .
Below you will find four files extracted of several Roms. Rename it to delete the words up to W.
However, all files has the same size and same md5. So. Code is the same for each.
Anyway, is up to you.
One interesting thing I watch with this problem is: the MAC Address did not change at all.
You can change between the files and MAC will remain.