After building my own ROM i got some problems with the devices drivers for the modem (the dual SIM was not recognized).
I discussed that with a few very skilled Android developers and the device drivers are the most important problem for building ROMs.
But there is something called GSI: Generic System Images.
The good point is that for my Samsung J530 there was a developer which built a project which allows to install GSIs:
With this plus Havoc 3.5
And here the steps to Android 10 (which where provided to me by Micro[ice]:
- install TWRP 3.3.0
- install create vendor 2.0
- reboot recovery
- install project spaget x
(if u get symlink error 7 flash revert vendor 2.0 and repeat from step 1 without revert vendor 2.0)
- install GSI (Havoc)-OS to system partition
(dont reboot after u flash project spaget x)
- if u need to flash gapps first u need to go
Wipe -> Advanced Wipe -> Tick System -> Repair -> Resize
(if u get error 1 resize again it will be successful) then u flash gapps
- (optional) flash areskernel rc2
- (optional) flash magisk