We use generate_dhs_patches
to collect all changes made by Sony in their
repo_update script save them as patch files.
First you need to have a plain AOSP tree initialized with the version matching to droid-hal e.g. in our case android-9.0.0-r46.
After that you need to delete the patches that were previously saved. For that you need to look that you don't delete the patches made by us or Jolla.
After the cleanup is done its now time to generate the new patches. For this you need to grab generate_dhs_patches and put it into the root of your android sources.
Now run:
droid_src_dir= # point it to your droid-src directory
./generate_dhs_patches.sh -m vendor \
-r "$PWD/repo_update.sh" \
-d $droid_src_dir/patches
After that commit your changes and you are done.