First you have already builded the all image base on the docs
If you change a single character (e.g. build.prop) again and don't want to take more times to rebuild the whole firmware again.
You can only pack the system and update image.
Follows below steps to have a try
1) Enter your project and lunch target
$ cd <path-your-project>
$ source build/envsetup.sh
$ lunch TARGET
2) Pack system image
$ make -jN snod
3) Pack update image
./vendor/amlogic/tools/aml_upgrade/aml_image_v2_packer -r out/target/product/TARGET/upgrade/aml_upgrade_package.conf out/target/product/TARGET/upgrade/ out/target/product/TARGET/update.img
- Replace 'N' as the number you want when you run 'make -jN'
- TARGET shoule be 32-bit for Android Marshmallow, and 64-bit for Android Nougat. For example:
For Andriod Marshmallow: lunch kvim-user-32
For Andriod Nougat: lunch kvim-user-64