Google GSI: Generic System Images for Smartphones

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.

(s. https://source.android.com/setup/build/gsi)

and:

The good point is that for my Samsung J530 there was a developer which built a project which allows to install GSIs:

https://forum.xda-developers.com/galaxy-j7-2017/development/treble-projecttreble-v1-0-jxy17lte-t3929286

With this plus Havoc 3.5

https://forum.xda-developers.com/galaxy-j7-2017/development/rom-crdroid-6-3-android-q-10-0-galaxy-t4048917

And here the steps to Android 10 (which where provided to me by Micro[ice]:

1. install TWRP 3.3.0
   
2. install create vendor 2.0
3. reboot recovery
4. 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)
5. install GSI (Havoc)-OS to system partition
   (dont reboot after u flash project spaget x)
6. 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
7. (optional) flash areskernel rc2
8. (optional) flash magisk
9. reboot
10. enjoy

And after that i have a running Android 10 on my Samsung J5... (without any Samsung Bloatware)

Lineage OS: Building my own system from scratch...

For my Samsung J5 is was only able to find a lineage 15.1 image but no lineage 16 or even 17.
So i decided to build the image on my own.

I followed this guide:
https://github.com/lineage-doge/device-j5y17lte/tree/lineage-16.0

But on this page the roomservice.xml is wrong:

Just change it to

The rest was following the instructions:

mkdir -p android/lineage-16.0
cd android/lineage-16.0
repo init -u git://github.com/LineageOS/android.git -b lineage-16.0
repo sync

Create .repo/local_manifests/roomservice.xml with the content shown above.
Then run "repo sync" once again.

Most important point it to extract the binaries from your device. To get a background just read this:
https://wiki.lineageos.org/extracting_blobs_from_zips.html


I extracted /system from my Android device via TWRP (under advanced you can find a file explorer and this can copy the partition to your sd card).
After that point STOCK_ROM_DIR to your sd card and run:

cd device/samsung/j5y17lte
STOCK_ROM_DIR=/path/to/system ./extract-files.sh

Now we are ready to rumble:

cd ../../
source build/envsetup.sh
brunch lineage_j5y17lte-userdebug

But after some minutes:

LD      kernel/built-in.o
/media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/kernel/samsung/exynos7870/drivers/net/wireless/Makefile:62: android version 1: 90000
/media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/kernel/samsung/exynos7870/drivers/net/wireless/Makefile:63: MAJOR_VERSION version 1: 9
/media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/kernel/samsung/exynos7870/drivers/net/wireless/Makefile:107: platform version 3 : 9.0.0
/media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/kernel/samsung/exynos7870/drivers/net/wireless/Makefile:108: MAJOR_VERSION version 3: 9
  LD      drivers/built-in.o
make[1]: Leaving directory '/media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/out/target/product/j5y17lte/obj/KERNEL_OBJ'
Makefile:145: recipe for target 'sub-make' failed
make: *** [sub-make] Error 2
make: Leaving directory '/media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/kernel/samsung/exynos7870'
[  1% 555/35382] target StaticLib: libv8src_32 (/media/schroff/895337b7-c4eb-44a4-...arget/product/j5y17lte/obj_arm/STATIC_LIBRARIES/libv8src_intermediates/libv8src.a)
ninja: build stopped: subcommand failed.
19:21:20 ninja failed with: exit status 1

#### failed to build some targets (05:29 (mm:ss)) ####

But this error is easy to fix:

cd ~/android/lineage-16.0/out/target/product/j5y17lte/obj/KERNEL_OBJ/firmware/tsp_imagis
cp ~/android/lineage-16.0/kernel/samsung/exynos7870/firmware/tsp_imagis/ist3038h_a3x_cmcs.bin .
~/android/lineage-16.0/kernel/samsung/exynos7870/firmware/tsp_imagis/ist3038h_a3x.fw .
schroff@zerberus:~/android/lineage-16.0/out/target/product/j5y17lte/obj/KERNEL_OBJ/firmware/tsp_imagis$

and try once again!

And after a while:

  Imgdiff Stats Report 
========================

Compressing system.new.dat with brotli
  running:  brotli --quality=6 --output=/tmp/tmpAOkKFk/system.new.dat.br /tmp/tmpAOkKFk/system.new.dat
using prebuilt boot.img from BOOTABLE_IMAGES...
  running:  java -Xmx2048m -Djava.library.path=/media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/out/host/linux-x86/lib64 -jar /media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/out/host/linux-x86/framework/signapk.jar -w build/target/product/security/testkey.x509.pem build/target/product/security/testkey.pk8 /tmp/tmptUxdfx.zip /tmp/tmpSgxnBy.zip
  running:  zip -d /tmp/tmpSgxnBy.zip META-INF/com/android/metadata
  running:  java -Xmx2048m -Djava.library.path=/media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/out/host/linux-x86/lib64 -jar /media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/out/host/linux-x86/framework/signapk.jar -w build/target/product/security/testkey.x509.pem build/target/product/security/testkey.pk8 /tmp/tmpSgxnBy.zip /media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/out/target/product/j5y17lte/lineage_j5y17lte-ota-eng.schroff.zip
done.
[100% 453/453] build bacon
Package Complete: /media/schroff/895337b7-c4eb-44a4-9063-00f629e5149f/lineage-16.0/out/target/product/j5y17lte/lineage-16.0-20200502-UNOFFICIAL-j5y17lte.zip

#### build completed successfully (27:31 (mm:ss)) ####