Originally Posted by jinjin12
How do i back up my EFS or IMEI on NExus 4? I searched google but there are basically no topics on this.
The only topics i found said that you don't need to back up EFS/IMEI on Nexus 4 since it's only really for samsung phones and google phones don't have EFS folders?
IS this true?
if so then how come there is a way to back up EFS for NEXUS 5 and not for nexus 4?
The Nexus 4 does NOT
have an EFS partition to back up, because the contents of the EFS folder are stored elsewhere where they do not need to be backed up.
Some unnecessary thoughts below
A quick Google tells me that LG has been using EFS partitions for awhile before the Nexus 4 was released, even the Optimus G has an EFS partition even though the Nexus 4 is based upon it. Google must have stored the IMEI/other EFS stuff elsewhere on the phone compared to the Optimus G to make the phone more developer friendly, probably in a hidden partition which you can't modify to prevent any corruption or deletion. If my theory is correct, this would explain why some Nexus 4s lose their IMEI after the partition table gets messed up, it probably corrupts said hidden partition, although that would not explain why I (or others) didn't lose my IMEI when I had to wipe the eMMC and reflash the partitions and all the system stuff with the LG download tool. Maybe the IMEI is stored in another chip on the motherboad, maybe on an EEPROM/NAND flash chip, and symlinked to the eMMC or otherwise linked to the eMMC? I dunno, just a thought