Android Device

This is a breakdown of the files build/envsetup.sh, Makefile and the files they use, which describes how a device is specified and how Android is configured for it.

For each file there are some comments and code lines from the make files or scripts, which describe what they are doing and which files they are using. Also the files which can be used as an example are presented and the commands how to search for them.

This text is for developers who want to add a new device or change the configuration of an existing device. This gives some indications which files are involved.

build/envsetup.sh
Some functions are defined by calling

. build/envsetup.sh in the top directory.

Some environment variables are set by calling lunch in the top directory.

export TARGET_PRODUCT=$product export TARGET_BUILD_VARIANT=$variant export TARGET_SIMULATOR=false export TARGET_BUILD_TYPE=release

vendorsetup.sh is searched at this places: vendor/*/vendorsetup.sh vendor/*/*/vendorsetup.sh device/*/*/vendorsetup.sh

vendorsetup.sh
This file is executed by build/envsetup.sh, and can use anything defined in envsetup.sh.

In particular, you can add lunch options with the add_lunch_combo function:

add_lunch_combo full_crespo-userdebug

The values of the macros TARGET_PRODUCT and TARGET_BUILD_VARIANT are derived from the option name: add_lunch_combo $TARGET_PRODUCT-$TARGET_BUILD_VARIANT In the above example the resulting values are TARGET_PRODUCT=full_crespo and TARGET_BUILD_VARIANT=userdebug.

These files can be used as an example: find. -name vendorsetup.sh

./device/samsung/crespo/vendorsetup.sh ./device/samsung/crespo4g/vendorsetup.sh ./device/htc/passion/vendorsetup.sh

Makefile
Build process is started by calling

make

in the top directory.

The Makefile calls build/core/main.mk

build/core/main.mk
Set up various standard variables based on configuration and host information. include $(BUILD_SYSTEM)/config.mk

This allows us to force a clean build - included after the config.make environment setup is done, but before we generate any dependencies. This file does the rm -rf inline so the deps which are all done below will be generated correctly

include $(BUILD_SYSTEM)/cleanbuild.mk

These are the modifier targets that don't do anything themselves, but change the behavior of the build. (must be defined before including definitions.make)

INTERNAL_MODIFIER_TARGETS := showcommands checkbuild all

Bring in standard build system definitions. include $(BUILD_SYSTEM)/definitions.mk

build/core/config.mk
Various mappings to avoid hard-coding paths all over the place

include $(BUILD_SYSTEM)/pathmap.mk

Try to include buildspec.mk, which will try to set stuff up. If this file doesn't exist, the environemnt variables will be used, and if that doesn't work, then the default is an arm build

-include $(TOPDIR)buildspec.mk

Define most of the global variables. These are the ones that are specific to the user's build configuration.

include $(BUILD_SYSTEM)/envsetup.mk

Search for BoardConfig.mk in $(SRC_TARGET_DIR)/board/$(TARGET_DEVICE)/BoardConfig.mk 		device/*/$(TARGET_DEVICE)/BoardConfig.mk 		vendor/*/$(TARGET_DEVICE)/BoardConfig.mk  and load the file

include $(board_config_mk)

include $(BUILD_SYSTEM)/dumpvar.mk

BoardConfig.mk
These files can be used as an example: find. -name BoardConfig.mk

./device/samsung/crespo/BoardConfig.mk ./device/samsung/crespo4g/BoardConfig.mk ./device/htc/passion/BoardConfig.mk ./build/target/board/generic/BoardConfig.mk ./build/target/board/generic_x86/BoardConfig.mk ./build/target/board/emulator/BoardConfig.mk ./build/target/board/sim/BoardConfig.mk

build/buildspec.mk.default
This is a do-nothing template file. To use it, copy it to a file named "buildspec.mk" in the root directory, and uncomment or change the variables necessary for your desired configuration. The file "buildspec.mk" should never be checked in to source control.

Choose a product to build for. Look in the products directory for ones that work. TARGET_PRODUCT

Choose a variant to build. If you don't pick one, the default is eng. User is what we ship. Userdebug is that, with a few flags turned on for debugging. Eng has lots of extra tools for development. TARGET_BUILD_VARIANT

CUSTOM_MODULES TARGET_SIMULATOR

Set this to debug or release if you care. Otherwise, it defaults to release for arm and debug for the simulator. TARGET_BUILD_TYPE

HOST_BUILD_TYPE DEBUG_MODULE_ModuleName TARGET_TOOLS_PREFIX HOST_CUSTOM_DEBUG_CFLAGS TARGET_CUSTOM_DEBUG_CFLAGS CUSTOM_LOCALES OUT_DIR ADDITIONAL_BUILD_PROPERTIES NO_FALLBACK_FONT WEBCORE_INSTRUMENTATION ENABLE_SVG BUILD_ENV_SEQUENCE_NUMBER

build/envsetup.mk
Set up version information. include $(BUILD_SYSTEM)/version_defaults.mk

If you update the build system such that the environment setup or buildspec.mk need to be updated, increment this number, and people who haven't re-run those will have to do so before they can build. Make sure to also update the corresponding value in buildspec.mk.default and envsetup.sh.

CORRECT_BUILD_ENV_SEQUENCE_NUMBER := 10

include $(BUILD_SYSTEM)/product_config.mk

TARGET_PRODUCT: sim full TARGET_BUILD_VARIANT: eng user userdebug tests

build/core/version_defaults.mk
Handle various build version information.

Guarantees that the following are defined: PLATFORM_VERSION PLATFORM_SDK_VERSION PLATFORM_VERSION_CODENAME DEFAULT_APP_TARGET_SDK BUILD_ID BUILD_NUMBER

Look for an optional file $(BUILD_SYSTEM)/build_id.mk containing overrides of the defaults INTERNAL_BUILD_ID_MAKEFILE include $(BUILD_SYSTEM)/build_id.mk

build/core/build_id.mk
BUILD_ID is usually used to specify the branch name BUILD_ID

DISPLAY_BUILD_NUMBER

build/product_config.mk
Provide "PRODUCT- - " targets, which lets you build a particular configuration without needing to set up the environment.

TARGET_PRODUCT := $(word 1,$(product_goals)) TARGET_BUILD_VARIANT := $(word 2,$(product_goals))

Provide "APP- " targets, which lets you build an unbundled app.

Include the product definitions. We need to do this to translate TARGET_PRODUCT into its underlying TARGET_DEVICE before we start defining any rules.

PRODUCT_DEVICE is defined in the product file $(TARGET_PRODUCT).mk. The product file $(TARGET_PRODUCT).mk is searched in the list of product make files $(PRODUCT_MAKEFILES). PRODUCT_MAKEFILES is set in AndroidProducts.mk files.

$(call import-products,$(call get-product-makefiles, $(SRC_TARGET_DIR)/product/AndroidProducts.mk))

Convert a short name like "sooner" into the path to the product file defining that product.

INTERNAL_PRODUCT := $(call resolve-short-product-name, $(TARGET_PRODUCT))

TARGET_DEVICE := $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_DEVICE) PRODUCT_LOCALES := $(strip $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_LOCALES)) PRODUCT_BRAND PRODUCT_MODEL PRODUCT_MANUFACTURER

PRODUCT_OTA_PUBLIC_KEYS

AndroidProducts.mk
This file should set PRODUCT_MAKEFILES to a list of product makefiles to expose to the build system. LOCAL_DIR will already be set to the directory containing this file.

This file may not rely on the value of any variable other than LOCAL_DIR; do not use any conditionals, and do not look up the value of any variable that isn't set in this file or in a file that it includes.

File device/samsung/crespo/AndroidProducts.mk PRODUCT_MAKEFILES := \ $(LOCAL_DIR)/full_crespo.mk

These files can be used as an example: find. -name AndroidProducts.mk

./device/sample/products/AndroidProducts.mk ./device/samsung/crespo/AndroidProducts.mk ./device/samsung/crespo4g/AndroidProducts.mk ./device/htc/passion/AndroidProducts.mk ./build/target/product/AndroidProducts.mk

The command which returns the list of all AndroidProducts.mk files is defined in build/core/product.mk : define _find-android-products-files $(shell test -d device && find device -maxdepth 6 -name AndroidProducts.mk) \ $(shell test -d vendor && find vendor -maxdepth 6 -name AndroidProducts.mk) \ $(SRC_TARGET_DIR)/product/AndroidProducts.mk endef

Product Files
Search for the files which can be used as an example: grep -R PRODUCT_DEVICE device build

device/samsung/crespo/full_crespo.mk:PRODUCT_DEVICE := crespo device/samsung/crespo4g/full_crespo4g.mk:PRODUCT_DEVICE := crespo4g device/htc/passion/full_passion.mk:PRODUCT_DEVICE := passion build/target/product/sdk.mk:PRODUCT_DEVICE := generic build/target/product/generic.mk:PRODUCT_DEVICE := generic build/target/product/generic_x86.mk:PRODUCT_DEVICE := generic_x86 build/target/product/core.mk:PRODUCT_DEVICE := generic build/target/product/full_x86.mk:PRODUCT_DEVICE := generic_x86 build/target/product/full.mk:PRODUCT_DEVICE := generic build/target/product/sim.mk:PRODUCT_DEVICE := sim

PRODUCT_DEVICE is used in these files build/core/product.mk:   PRODUCT_DEVICE \ build/core/product_config.mk:TARGET_DEVICE := $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_DEVICE)

Add new device
Add the configuration files for the new device mydevice of the company mycompany.

Create AndroidProducts.mk mkdir -p device/mycompany/mydevice nano device/mycompany/mydevice/AndroidProducts.mk

PRODUCT_MAKEFILES := \ $(LOCAL_DIR)/full_mydevice.mk

Create file full_mydevice.mk Example is build/target/product/full.mk nano device/mycompany/mydevice/full_mydevice.mk

$(call inherit-product, $(SRC_TARGET_DIR)/product/full_base.mk) $(call inherit-product, $(SRC_TARGET_DIR)/board/generic/device.mk)

PRODUCT_NAME := full_mydevice PRODUCT_DEVICE := mydevice PRODUCT_BRAND := Android PRODUCT_MODEL := Full Android on mydevice
 * 1) Overrides

Create file vendorsetup.sh nano device/mycompany/mydevice/vendorsetup.sh

add_lunch_combo full_mydevice-eng

Create file BoardConfig.mk

Examples are build/target/board/generic/BoardConfig.mk device/samsung/crespo/BoardConfig.mk device/samsung/crespo/BoardConfigCommon.mk

mkdir -p device/mycompany/mydevice nano device/mycompany/mydevice/BoardConfig.mk


 * 1) config.mk
 * 2) Product-specific compile-time definitions.
 * 1) Product-specific compile-time definitions.

TARGET_NO_BOOTLOADER := true TARGET_NO_KERNEL := true TARGET_CPU_ABI := armeabi HAVE_HTC_AUDIO_DRIVER := true BOARD_USES_GENERIC_AUDIO := true
 * 1) The generic product target doesn't have any hardware-specific pieces.

USE_CAMERA_STUB := true
 * 1) no hardware camera

TARGET_SHELL := mksh
 * 1) Set /system/bin/sh to mksh, not ash, to test the transition.

TARGET_ARCH_VARIANT := armv7-a-neon ARCH_ARM_HAVE_TLS_REGISTER := true
 * 1) CPU

Configure Android for mydevice . build/envsetup.sh

including device/htc/passion/vendorsetup.sh including device/mycompany/mydevice/vendorsetup.sh including device/samsung/crespo4g/vendorsetup.sh including device/samsung/crespo/vendorsetup.sh

lunch

You're building on Linux

Lunch menu... pick a combo: 1. full-eng 2. full_x86-eng 3. simulator 4. full_passion-userdebug 5. full_mydevice-eng 6. full_crespo4g-userdebug 7. full_crespo-userdebug

Which would you like? [full-eng] 5

=
=============================== PLATFORM_VERSION_CODENAME=AOSP PLATFORM_VERSION=AOSP TARGET_PRODUCT=full_mydevice TARGET_BUILD_VARIANT=eng TARGET_SIMULATOR=false TARGET_BUILD_TYPE=release TARGET_BUILD_APPS= TARGET_ARCH=arm TARGET_ARCH_VARIANT=armv7-a-neon HOST_ARCH=x86 HOST_OS=linux HOST_BUILD_TYPE=release BUILD_ID=OPENMASTER

=
===============================

Build Android for mydevice make -j4

Combining NOTICE files: out/target/product/mydevice/obj/NOTICE.html Target system fs image: out/target/product/mydevice/obj/PACKAGING/systemimage_intermediates/system.img Install system fs image: out/target/product/mydevice/system.img Installed file list: out/target/product/mydevice/installed-files.txt