Wi-Fi cannot turn on! Accidentally deleted /etc/wifi folder i was trying to enable ad hoc network connection on android and overwriting below folders

/etc/wifi

/etc/dhcpcd

and now my wifi could not turn on. The phone is ADINNO R8, a custom build phone.I could not find its ROM on the internet and most of software does not recognize it.

it runs on 4.2.1 Jelly bean.

tried:


USB internet


USB internet to upgrade firmware within OS(seems to use wifi driver as well which are corrupted, so there is no internet connection)


3rd party fixer


download WiFi fixer and not working


other version/wifi folders


downloaded some WiFi folders people upload on the internet and none of them are working.(maybe because this is a rare custom phone)


Recovery


tried recovery and wipe all data in setting, still no luck, wifi folder still corrupted.

i could think of three methods, both failed.


reflash its OS.(failed as could not find its ROM)
upgrade its OS.(failed as no internet access, WiFi not working)
Replace /etc/wifi found on internet (failed as no compatible version)


is there anyway i could fix it?
Try harder to find firmware images for your phone. A factory reset might not work, as it only wipes data and cache partition. The etc folder is in /system/etc, /etc usually just is a link to /system/etc. Therefore you would need an image of the system partiton.
Well, if you can't find such firmware, it might not be a device thats common used, and therefore - if you are lucky - there was not a lot of money around for software adaptations from the manufacturor. Try to get firmware for similar devices, watch out for the same android version, and second on similar hardware / components. Download these images, unpack them and try to find the needed files.
Maybe you can just grab another device, from a friend or so, and look for the files. You might also consider having a look on aosp and taking the files from there. Watch out for the correct android version.