Building SDK addon of custom Android (system) image

[Olexandr Tereshchuk]

Hi,
I'm working on a custom Android-based OS.

I've already configured x86 emulator build - basically it's a full_x86 modification: company_emulatorx86.mk

PRODUCT_COPY_FILES += ...

# Inherit from the common Open Source product configuration
$(call inherit-product, $(SRC_TARGET_DIR)/product/full_x86.mk)


PRODUCT_NAME := company_emulatorx86
PRODUCT_BRAND := COMPANY
PRODUCT_MODEL := COMPANY on emulatorx86


DEVICE_PACKAGE_OVERLAYS += ...

But now, I want to distribute this as SDK addon. I've created and filled source.properties and manifest.ini files.
At this point I can simply build my company_emulatorx86 target, package it into zip, add addon.xml file and distribute.

But I know that there is make-targets to generate addon zip and xml automatically. Probably, the most remarkable combination is:

make -j4 PRODUCT-company_emulatorx86-sdk_addon dist DIST_DIR=~/android/source/out/addon

But here is the problem:

1. It would build 'eng' target - how to configure it ?
   
2. How to put provide hardware.ini, manifest.ini and source.properties ?
   
3. How to generate addon.xml file which can be used in Android SDK manager then ?

P.S. AFAIK you can inherit $(SRC_TARGET_DIR)/product/sdk.mk and use bunch of PRODUCT_* variables to configure addon, but how can I define that configured addon should contain my company_emulatorx86 images ?