How to update bootloader

Hunsu

New Member
Mar 10, 2017
6
0
1
#1
So that now most custom ROM switched to kernel 4.4, I must update bootloader.
I flashed many ZUI (2.5, 3.5 and 3.7) ROM using TWRP but none of them worked.

Do I need to use QFIL ? If yes can you please provide me with a guide that works. I bought my at end of 2016 and never installed ZUI ROM.
 

DarkWinterCloud

Well-Known Member
Jan 20, 2017
701
306
63
Brasil
www.profixstore.com.br
#2
Bootloader is a part of the system that doesnt have version, it cant be upgraded or flashed, unless by a hardware method of direct flashing the NAND memory (a JTAG Box for instance). I dont think you need to update your bootloader, it would have no use.
You can flash the system, userdata, recovery, baseband and another less known partitions manually, but the bootloader normally doesnt get flashed or updated with just a ROM flash.

What exactly is your problem?
 

DarkWinterCloud

Well-Known Member
Jan 20, 2017
701
306
63
Brasil
www.profixstore.com.br
#4
I get the blue screen every time I flash a ROM with 4.4 kernel.
When you flash a custom rom, you need to be aware of what was the "base" system you had installed before (i.e ZUI 3.4, 3.5, 4.0)
If you install an 8.0 Version Rom on a 7.0 base system, in some cases, the kernel may cause problems with the device.

What you can do is:
1- flash the latest stock firmware available for your device (look into the forum for links) using Qfil
2- Unlock the bootloader again
3- install latest TWRP version from here: https://twrp.me/zuk/zukz2.html
4- get your custom rom files (take care and read the installing instructions on the thread you got it)
5- WIPE System, Data, Cache WITHOUT rebooting the phone after the process
6- reinstall the rom file, after the wipes, connect the phone to the PC, and copy the rom file to the device.

Try not to mess with Kernel if you're not sure of what you're doing. Sometimes Wrong kernels can cause Bricks on the device (like the one you have right now)
You cant install any Kernel on any system versions, there are always requirements, check then BEFORE trying anything new.

Check this thread for more info on how to do the steps correctly:
https://zukfans.eu/community/threads/guide-how-to-properlly-install-a-custom-rom-newbie.6590/

Best regards!
 

DarkWinterCloud

Well-Known Member
Jan 20, 2017
701
306
63
Brasil
www.profixstore.com.br
#6
Thanks for the detailed answer. So I must use QFIL and I can't flash the stock ROMs using TWRP ?
Its more a safe route to recover the stock state of the phone. QFIL is the safer way.

Recovery flashable stock roms works too, when your phone is working. Since youre getting bluescreens, flash with QFIL and it may resolve the problem.

then, after everything is working properly, you can try to flash a custom rom again. Just dont mess with kernel stuff for now, they seem to be a good way to get a better performance from the phone, but most of the times the kernel that comes with the rom are the best kernel for that rom, otherwise the developer would do the proper changes...

Custom kernels are good when you know how to make then work the way you want. If youre just thinking in flash a custom kernel because you just want to do this and think that it will give you a better performance, it just prove that you dont know what youre doing.

Do some research about how to tweak kernels, the way that the governors works, tdp, undervolt, this kind of stuff.
But if youre feeling lazy about it, just flash the rom and be happy with it. Sometimes the gains are so little that its not worth the hassle and you can f*ck things up on the phone, you may want to avoid this.

Hope you understand the message :)