One of the most common customization actions to perform in Android firmware is to establish the default applications and libraries that will be compiled and included in the final Android image. These items are defined in the `PRODUCT_PACKAGES` variable that is declared and extended in several Android makefiles in the sources. This is a brief list of makefiles containing the most important applications and libraries that will be included in the final Android firmware:

• `device/digi/imx8m/ccimx8mmdvk/ccimx8mmdvk.mk`

• `device/digi/imx8m/ProductConfigCommon.mk`

• `build/target/product/generic.mk`

• `build/target/product/generic_no_telephony.mk`

• `build/target/product/handheld_system.mk`

• `build/target/product/media_system.mk`

• `build/target/product/base_system.mk`

• `build/target/product/handheld_system_ext.mk`

• `build/target/product/media_system_ext.mk`

• `build/target/product/base_system_ext.mk`

• `build/target/product/handheld_vendor.mk`

• `build/target/product/media_vendor.mk`

• `build/target/product/base_vendor.mk`

• `build/target/product/handheld_product.mk`

• `build/target/product/media_product.mk`

• `build/target/product/base_product.mk`

• `build/target/product/telephony.mk`

• `build/target/product/telephony_system.mk`

• `build/target/product/telephony_system_ext.mk`

• `build/target/product/telephony_vendor.mk`

• `build/target/product/telephony_product.mk`

 The makefiles of the list are sorted by calling order, from product specific to Android core.

Each application or library is identified by its:

• `name` in the component `Android.bp` file

• or `LOCAL_PACKAGE_NAME` in the component `Android.mk` file

This is an example of the Gallery2 application `Android.bp` file:

Gallery2 Android.bp
``````android_app {
name: "Gallery2",

static_libs: [
"androidx.fragment_fragment",
"androidx.legacy_legacy-support-core-ui",
"androidx.core_core",
"androidx.legacy_legacy-support-v13",
"com.android.gallery3d.common2",
"xmp_toolkit",
"mp4parser",
],

srcs: [
"src/**/*.java",
"src_pd/**/*.java",
],

resource_dirs: ["res"],

product_specific: true,

overrides: [
"Gallery",
"Gallery3D",
"GalleryNew3D",
],

sdk_version: "current",

jni_libs: [
"libjni_eglfence",
"libjni_filtershow_filters",
"libjni_jpegstream",
],

optimize: {
proguard_flags_files: ["proguard.flags"],
},

libs: ["org.apache.http.legacy"],

jarjar_rules: "jarjar-rules.txt",
}``````

Note that the `name` of the Gallery2 application is `Gallery2`. This will identify the component in all Android sources.

 For more information about Android build system, see https://source.android.com/setup/build

## Remove a default application or library

To remove a default application or library from your custom Android firmware, you must delete all the entries of that component from the `PRODUCT_PACKAGES` variable. To do so, look for the component identifier in the list of makefiles presented before and remove all the entries you find.

 The same application or library could be declared in more than one makefile. Digi recommends you check the list of makefiles listed before to ensure that the component is fully removed.

For example, to remove the Gallery2 application you need to remove the `Gallery2 \` entry from the `build/target/product/handheld_product.mk` file. (It is not defined anywhere else.)

build/target/product/handheld_product.mk
``````[...]
PRODUCT_PACKAGES += \
Browser2 \
Calendar \
[...]
Gallery2 \
LatinIME \
Music \
[...]
frameworks-base-overlays``````
 Removing applications or libraries may cause other Android components to stop working properly. Do so carefully.