What is oeminfo?
Oeminfo is a partition in Huawei devices that defines what regional settings will be applied on boot.
How does it work?
No one except Huawei knows what exactly this partition contains. It can't be mounted, most likely doesn't contain files and its format is undefined.
The only thing we know is that changing its content to the one from device of another country makes your device think it's from that country.
Also we know that the device somehow reads this partiton and decides what folder from cust partiton to read and link to.
What's all that for?
As we know, Chinese manufacturers often forget to update devices from countries other than China. It makes their owners frustrate and dream of new features they'll possibly never get.
How to know what oeminfo do i have?
First of all, go to "About device" and look at build number. For example, my Russian tablet has BTV-DL09C100B005 number. BTV-DL09 is model, C100 is region my firmware belongs to and B005 is version.
At this moment we can find the newest chinese firmware, which build number is BTV-DL09C233B026. C233 is Chinese region and this firmware brings some new features to EMUI like posibility to hide navigation bar, set screen density to apps etc. Of course if your region differs from C233, you won't see this update with Update menu.
Also, you can type *#*#2846579#*#* in dialer, go to Network Information Query and then to Vendor Country info. My device shows Vendor: hw, Country: ru.
How to backup oeminfo?
I know 3 ways:
1) With TWRP backup feature
2) With dd from TWRP adb shell
3) With ES Explorer.
1) Backup with TWRP is easy and doesn't need an explanation.
2) To backup with dd go to TWRP, connect your device to the computer, type adb shell in command line and you'll be in TWRP console.
Now type dd if=/dev/block/platrofm/hi_mci.0/by-name/oeminfo of=/sdcard/oeminfo.img and you'll get a byte-to-byte copy of oeminfo partition in internal storage.
3) To backup with ES Explorer, you'll need root access. If you have if, go to /dev/block/platrofm/hi_mci.0/by-name/ and copy oeminfo to another place.
I don't know which way is the most correct, but owners of another Huawei devices change oeminfo with ES Explorer and sometimes dd.
So, what do you, guys, think? If someone has Chinese DL09 with C233 region, please, share your oeminfo, so other people could get updates.