If I change any character in the firmware file and try to flash it, it will failed. But it will successfully flashed if I changed the string with the same number of character if it's not a function.
After further searching, I found out about the checksum and that in order to flash the custom firmware, you need to calculate it and modify it in the firmware.
This is the firmware:
I use HxD to read the file.
If I search for checksum, I got some results ->
Also, I searched for sha ->
So here, I tried to change == with != and also I changed it to 1 == 1 but, It always failed to flash
I am lost. I don't know what to search for or from where to start.
I hope that someone could help me out!
Note: I can provide access to my PC to try the flash tool (nokia tool v0.060 using easybox) and maybe debugging in the phone.