Here I present you my Flash tool rom base for Jiayu G4s.
Not for beginners , follow the steps preciselly please!
It makes system partition bigger (data smaller) to prepare for larger roms to be installed via TWRP.
It includes insecured boot and my twrp recovery already. Also is restores nvram.
Instructions.
Download zip and unpack , in a directory (Preferably c:/G4S).
Copy inside this directory your nvram bin backup from MTKdroid tools, renamed nvram.bin. (You have one right?)
Open Flash tools and load scatter.txt from G4S folder.
Now choose Format menu on top , make sure Format whole flash except bootloader is chosen and press start button.
Remove battery from phone , keep it removed and connect usb cable with pc and mobile. If you have drivers installed , the format proccess will start. If not install MTK Vcom drivers to the device that pops up in device manager of pc.
When it is finished , remove usb.
No go back to Download menu and make sure all fields are filled with files in location column.
Choose Download only and press the Download button. Reconnect pc-mobile , still without battery.
When it is finished remove USB and connect battery.
Now press the vol+ button , connect usb and while still pressing vol+ briefly press the power button.
Keep vol+ pressed , you will see Jiayu logo. When you see recovery logo release vol+. Now you are in TWRP..
Now do these step in wipe menu , exaclty in this order. (PS by this time you don't have and system cache and data partition, they must be formatted)
Goto wipe menu. Press advanced wipe , and wipe in this order.
First system – swipe wipe. Then cache – swipe wipe and finally Data – swipe wipe.
Reboot phone in recovery again. The phone will complain you have no OS installed when you choose to reboot so ignore that and choose yes , reboot.. Check that you can mount all partitions after you re-enter TWRP.
If you can't repeat the wipes again in same order.
Finally flash from twrp your favorite rom.