第第頁安卓基礎知識總結(jié)1.Android編譯系統(tǒng)分析

2.文件系統(tǒng)分析

3.制作交叉工具鏈

4.軟件編譯常識

5.設置模塊流程分析

6.linux系統(tǒng)啟動流程分析

7.linux下svn使用指南

8.LFS相關

9.linux內(nèi)核的初步理解

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android系統(tǒng)開發(fā)指南(常用環(huán)境的搭建和使用)

說明:

有的步驟會用到腳本簡化操作，腳本通過svn服務器獵?。?/p>

svncosvn://48/smartphone/td0901/release/images/scripts

用戶名為各位的姓名拼音，密碼與用戶名相同

一編譯android源碼，制作文件系統(tǒng)

二ubuntu下燒錄內(nèi)核和文件系統(tǒng)

一編譯android源碼，制作文件系統(tǒng)

1.開發(fā)主線源碼位置：

svn://48/smartphone/td0901/trunk/cupcake-jianping//cupcake源代碼

svn://48/smartphone/td0901/trunk/linux-2.6.28-a1//內(nèi)核源代碼

2.打標的源代碼位置

svnlistsvn://48/smartphone/td0901/tag

我們可以通過svnlistsvn://48/smartphone查看svn版本庫內(nèi)核

更多信息請參卡以下文檔：

48/svn/smartphone/

48/svn/smartphone/智能平臺開發(fā)部資料管理手冊V1.0.doc

48/svn/smartphone/linux下svn操作指南及規(guī)范.doc

用戶名為各位的姓名拼音，密碼與用戶名相同

3.編譯源碼

進入cupcake工作拷貝的頂層名目，執(zhí)行：

../make_image15.sh

部分執(zhí)行結(jié)果：

out/target/product/littleton/root/內(nèi)核需要使用的initramfs

out/target/product/littleton/system文件系統(tǒng)的系統(tǒng)分區(qū)

out/target/product/littleton/data/文件系統(tǒng)數(shù)據(jù)分區(qū)

4.編譯內(nèi)核

此處內(nèi)核編譯主要針對驅(qū)動組之外的同事

1設置工具鏈

內(nèi)核的linux-2.6.28-a1/Makefile中設定了：

CROSS_COMPILE?=arm-linux-

所以設置PATH環(huán)境變量，保證能找到正確的工具鏈

假設工具鏈位于：/usr/local/marvell-arm-linux-4.1.1/設置為：

exportPATH:=/usr/local/marvell-arm-linux-4.1.1/bin/:$PATH

2更改編譯選項(網(wǎng)絡啟動或者本機啟動)

內(nèi)核頂層名目執(zhí)行：

makemenuconfig

Generalsetup

#InitialRAMfilesystemandRAMdisk(initramfs/initrd)support

()Initramfssourcefile(s)(NEW)

假如需要支持網(wǎng)絡啟動反選[]InitialRAMfilesystemandRAMdisk(initramfs/initrd)support

假如需要支持本地啟動選中

#InitialRAMfilesystemandRAMdisk(initramfs/initrd)support

設置()Initramfssourcefile(s)(NEW)為root

拷貝cupcake編譯結(jié)果out/target/product/littleton/root/到內(nèi)核頂層名目

3編譯

內(nèi)核頂層名目執(zhí)行makezImage

編譯好的內(nèi)核：

arch/arm/boot/zImage

5.搭建網(wǎng)絡開發(fā)環(huán)境

1安裝nfs服務器

sudoapt-getinstallnfs-kernel-servernfs-common

2修改nfs服務器配置文件/etc/exports，確保有以下配置項

/nfsroot/rootfs*(rw,no_root_squash,sync)

我們在內(nèi)核中已經(jīng)固定，手機通過網(wǎng)絡方式啟動，默認從/nfsroot/rootfs

讀取文件系統(tǒng)，修改配置項后需要重啟nfs服務器：

sudo/etc/init.d/nfs-kernel-serverrestart

3配置網(wǎng)絡根文件系統(tǒng)

拷貝out/target/product/littleton/root/內(nèi)容到/nfsroot/rootfs名目

拷貝out/target/product/littleton/system內(nèi)容到/nfsroot/rootfs/system

修改/nfsroot/rootfs/init.rc去掉幾個mount指令

為了使大家的過程，結(jié)果統(tǒng)一，可以使用腳本mkfs.cupcake完成

在執(zhí)行mkfs.cupcake.nfs腳本前先到cupcake-jianping名目下執(zhí)行:../make_env15.sh設置環(huán)境變量,

獵取通過手動輸入android源碼的位置，讓腳原來設置環(huán)境變量。

二ubuntu下燒錄內(nèi)核和文件系統(tǒng)

1.硬件：

手機一臺

usb轉(zhuǎn)串口線一根

usb轉(zhuǎn)網(wǎng)卡線一根

2.軟件環(huán)境

1tftp服務器

執(zhí)行腳本：setup_tftpd.sh安裝和配置tftp服務器，我們默認以/tftpboot

為tftp服務器的根名目，需要下載的文件都放在該名目下。

2獵取待燒錄的鏡像文件

svnlistsvn://48/smartphone/td0901/release/images查看服務器上的

版本狀況，通常我們下載最新的,例如，下載9月18號發(fā)布的版本：

svncosvn://48/smartphone/td0901/release/images/images20230918

3燒錄鏡像文件

用以下文件為例，示范通過tftp燒寫內(nèi)核和文件系統(tǒng)

內(nèi)核zImage0917

系統(tǒng)分區(qū)：system0918.img

數(shù)據(jù)分區(qū)data0918.img

待燒寫的以上文件必需存在于tftp服務器根名目/tftpboot下。

詳細步驟：

首先連接好硬件設備進入blob下載模式

1blob起來后按任意鍵

Processingobmparameters...

Cantdetectmicco.SetPMICasnormalI2Cmode.

NANDflash(Manu=0x98Device=0xba)detected!

Slot0Found

getrelocationtable

FoundMainBadblocktableataddress0x0f000000,version0x01

FoundMirrorBadblocktableataddress0x0efc0000,version0x01

ConsideryourselfBLOBed!

blobversion2.0.5-pre3forMarvellLittleton

Copyright(C)19992000202320232023Jan-DerkBakkerandErikMouw

blobcomeswithABSOLUTELYNOWARRANTY;readtheGNUGPLfordetails.

Thisisfreesoftware,andyouarewelcometoredistributeit

undercertainconditions;readtheGNUGPLfordetails.

lengthnotalignwithpagesize,changeto0x0

Readflashfrom0x60000,length0x0

Done

Autoboot(2seconds)inprogress,pressanykeytostop..

Autobootaborted

Typehelptogetalistofcommands

blob

2通過tftp下載內(nèi)核到pc內(nèi)存0x80800000地址處

blobtftpzImage0917

Begininitetherusbnet!!!

*****Plug-inUSBcableconfigusbdnetnow******

exitcheck_usb_connection:1

TFTPingzImage0917*^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^OK.

received6144blocks(3145156bytes)

tftp_cmd:filezImage0917loadedviatftptoaddress0x80800000.

3擦除原來的內(nèi)核分區(qū)，0x100000為分區(qū)起始地址，0x300000為分區(qū)長度

blobnanderase-z0x1000000x400000

thecurrentNANDchipdoesnotsupportBlockUnlocking.

Erase0x300000lengthdatafromflash:0x100000

Eraseflashfrom0x100000,length0x300000

Done

4燒寫內(nèi)存0x80800000開頭實際長度為3145156的內(nèi)核數(shù)據(jù)到起始地址為0x100000的內(nèi)核分區(qū)

blobnandwrite-z0x808000000x1000003145156

thecurrentNANDchipdoesnotsupportBlockUnlocking.

Write0x2ffdc4lengthdatafromRAM:0x80800000toflash:0x100000

Writeflashfrom0x100000,length0x2ffdc4

Eraseflashfrom0x100000,length0x300000

Done

Done

5下載系統(tǒng)分區(qū)鏡像文件到pc內(nèi)存0x80800000地址處

blobtftpsystem0918.img

TFTPingsystem0918.img*^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^OK.

received113138blocks(57925824bytes)

tftp_cmd:filesystem0918.imgloadedviatftptoaddress0x80800000.

6擦除原來的flash系統(tǒng)分區(qū)

blobnanderase-z0x5000000x4000000

thecurrentNANDchipdoesnotsupportBlockUnlocking.

Erase0x3e0f800lengthdatafromflash:0x400000

Eraseflashfrom0x400000,length0x3e0f800

Done

7燒寫數(shù)據(jù)到flash系統(tǒng)分區(qū)

blobnandwrite-y0x808000000x50000057925824

thecurrentNANDchipdoesnotsupportBlockUnlocking.

Write0x373e0c0lengthdatafromRAM:0x80800000toflash:0x400000

Writeflashfrom0x400000,length0x3591800

Eraseflashfrom0x400000,length0x3591800

Done

Done

8下載數(shù)據(jù)分區(qū)鏡像文件到pc內(nèi)存0x80800000地址處

blobtftpdata0918.img

TFTPingdata0918.img*^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^OK.

received33992blocks(17402880bytes)

tftp_cmd:filedata0918.imgloadedviatftptoaddress0x80800000.

blob

9擦除原來的flash數(shù)據(jù)分區(qū)

blobnanderase-z0x45000000xBB00000

thecurrentNANDchipdoesnotsupportBlockUnlocking.

Erase0xa81f000lengthdatafromflash:0x4400000

Eraseflashfrom0x4400000,length0xa81f000

Done

10燒寫數(shù)據(jù)鏡像到flash數(shù)據(jù)分區(qū)

blobnandwrite-y0x808000000x450000017402880

thecurrentNANDchipdoesnotsupportBlockUnlocking.

Write0x1098c00lengthdatafromRAM:0x80800000toflash:0x4400000

Writeflashfrom0x4400000,length0x1018000

Eraseflashfrom0x4400000,length0x1018000

Done

Done

blob

flash分區(qū)圖：

*******************************************

*****

*blob*kernel*system*data*

*****

*******************************************

nanderase-z0x1000000x400000

tftpzImage

nandwrite-z0x808000000x100000

燒寫system.img：

nanderase-z0x5000000x4000000

tftpsystem.img

nandwrite-y0x808000000x500000

燒寫userdata.img：

nanderase-z0x45000000xBB00000

tftpuserdata.img

nandwrite-y0x808000000x4500000

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

涉及的內(nèi)容：

svn服務器的使用

android的編譯系統(tǒng)，原理，工具鏈，幫助工具，參數(shù)等，環(huán)境變量，怎樣單獨添加編譯一個單獨的模塊等。

android的編譯結(jié)果：文件系統(tǒng)分析

文件系統(tǒng)的使用，啟動流程

設置模塊流程分析

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1.Android編譯系統(tǒng)分析

編譯腳本及系統(tǒng)變量

build/envsetup.sh腳本分析

在編譯源代碼之前通常需要在android源代碼頂層名目執(zhí)行../build/envsetup.sh目的是為了使用

腳本envsetup.sh里面定義了一些函數(shù)：

functionhelp()

functionget_abs_build_var()

functionget_build_var()

functioncheck_product()

functioncheck_variant()

functionsetpaths()

functionprintconfig()

functionset_stuff_for_environment()

functionset_sequence_number()

functionsettitle()

functionchoosetype()

functionchooseproduct()

functionchoosevariant()

functiontapas()

functionchoosecombo()

functionprint_lunch_menu()

functionlunch()

functiongettop

functionm()

functionfindmakefile()

functionmm()

functionmmm()

functioncroot()

functionpid()

functiongdbclient()

functionjgrep()

functioncgrep()

functionresgrep()

functiongetprebuilt

functiontracedmdump()

functionrunhat()

functiongetbugreports()

functionstartviewserver()

functionstopviewserver()

functionisviewserverstarted()

functionsmoketest()

functionruntest()

functionruntest_py()

functiongodir()

choosecombo指令分析：

functionchoosecombo()

{

choosesim$1

echo

echo

choosetype$2

echo

echo

chooseproduct$3

echo

echo

choosevariant$4

echo

set_stuff_for_environment

printconfig

}

會依次進行如下選擇：

Buildforthesimulatororthedevice?

1.Device

2.Simulator

Whichwouldyoulike?[1]

Buildtypechoicesare:

1.release

2.debug

Whichwouldyoulike?[1]

Productchoicesare:

1.emulator

2.generic

3.sim

4.littleton

Youcanalsotypethenameofaproductifyouknowit.

Whichwouldyoulike?[littleton]

Variantchoicesare:

1.user

2.userdebug

3.eng

Whichwouldyoulike?[eng]user

默認選擇以后會消失：

TARGET_PRODUCT=littleton

TARGET_BUILD_VARIANT=user

TARGET_SIMULATOR=false

TARGET_BUILD_TYPE=release

TARGET_ARCH=arm

HOST_ARCH=x86

HOST_OS=linux

HOST_BUILD_TYPE=release

BUILD_ID=

==========

functionchooseproduct()函數(shù)分析：

choices=(`/bin/lsbuild/target/board/*/BoardConfig.mkvendor/*/*/BoardConfig.mk2/dev/null`)

讀取build/target/board/*名目下的板配置文件：BoardConfig.mk

讀取vendor/*/*/名目下的板配置文件：BoardConfig.mk

choices的值為：

build/target/board/emulator/BoardConfig.mk

build/target/board/generic/BoardConfig.mk

build/target/board/sim/BoardConfig.mk

vendor/marvell/littleton/BoardConfig.mk

經(jīng)過：

forchoicein${choices[@]}

do

#Theproductnameisthenameofthedirectorycontaining

#themakefilewefound,above.

prodlist=(${prodlist[@]}`dirname${choice}|xargsbasename`)

done

的處理，prodlist的值為：

emulatorgenericsimlittleton

所以選擇菜單為：

Productchoicesare:

1.emulator

2.generic

3.sim

4.littleton

假如選擇4，那么TARGET_PRODUCT被賦值為：littleton。

board_config_mk:=/

$(strip$(wildcard/

$(SRC_TARGET_DIR)/board/$(TARGET_DEVICE)/BoardConfig.mk/

vendor/*/$(TARGET_DEVICE)/BoardConfig.mk/

))

怎樣添加一個模塊

LOCAL_PATH:=$(callmy-dir)

#編譯靜態(tài)庫

include$(CLEAR_VARS)

LOCAL_MODULE=libhellos

LOCAL_CFLAGS=$(L_CFLAGS)

LOCAL_SRC_FILES=hellos.c

LOCAL_C_INCLUDES=$(INCLUDES)

LOCAL_SHARED_LIBRARIES:=libcutils

LOCAL_COPY_HEADERS_TO:=libhellos

LOCAL_COPY_HEADERS:=hellos.h

include$(BUILD_STATIC_LIBRARY)

#編譯動態(tài)庫

include$(CLEAR_VARS)

LOCAL_MODULE=libhellod

LOCAL_CFLAGS=$(L_CFLAGS)

LOCAL_SRC_FILES=hellod.c

LOCAL_C_INCLUDES=$(INCLUDES)

LOCAL_SHARED_LIBRARIES:=libcutils

LOCAL_COPY_HEADERS_TO:=libhellod

LOCAL_COPY_HEADERS:=hellod.h

include$(BUILD_SHARED_LIBRARY)

BUILD_TEST=true

ifeq($(BUILD_TEST),true)

#使用靜態(tài)庫

include$(CLEAR_VARS)

LOCAL_MODULE:=hellos

LOCAL_STATIC_LIBRARIES:=libhellos

LOCAL_SHARED_LIBRARIES:=

LOCAL_LDLIBS+=-ldl

LOCAL_CFLAGS:=$(L_CFLAGS)

LOCAL_SRC_FILES:=mains.c

LOCAL_C_INCLUDES:=$(INCLUDES)

include$(BUILD_EXECUTABLE)

#使用動態(tài)庫

include$(CLEAR_VARS)

LOCAL_MODULE:=hellod

LOCAL_MODULE_TAGS:=debug

LOCAL_SHARED_LIBRARIES:=libclibcutilslibhellod

LOCAL_LDLIBS+=-ldl

LOCAL_CFLAGS:=$(L_CFLAGS)

LOCAL_SRC_FILES:=maind.c

LOCAL_C_INCLUDES:=$(INCLUDES)

include$(BUILD_EXECUTABLE)

endif#ifeq($(WPA_BUILD_SUPPLICANT),true)

########################

#local_target_dir:=$(TARGET_OUT)/etc/wifi

#include$(CLEAR_VARS)

#LOCAL_MODULE:=wpa_supplicant.conf

#LOCAL_MODULE_TAGS:=user

#LOCAL_MODULE_CLASS:=ETC

#LOCAL_MODULE_PATH:=$(local_target_dir)

#LOCAL_SRC_FILES:=$(LOCAL_MODULE)

#include$(BUILD_PREBUILT)

########################

系統(tǒng)變量解析

LOCAL_MODULE-編譯的目標對象

LOCAL_SRC_FILES-編譯的源文件

LOCAL_C_INCLUDES-需要包含的頭文件名目

LOCAL_SHARED_LIBRARIES-鏈接時需要的外部庫

LOCAL_PRELINK_MODULE-是否需要prelink處理

BUILD_SHARED_LIBRARY-指明要編譯成動態(tài)庫

LOCAL_PATH-編譯時的名目

$(call名目，名目)名目引入操作符

如該名目下有個文件夾名稱src，則可以這樣寫$(callsrc)，那么就會得到src名目的完好路徑

include$(CLEAR_VARS)-去除之前的一些系統(tǒng)變量

CLEAR_VARS:=$(BUILD_SYSTEM)/clear_vars.mk

在build/core/config.mk定義CLEAR_VARS:=$(BUILD_SYSTEM)/clear_vars.mk

通過include包含自定義的.mk文件(即是自定義編譯規(guī)章)或是引用系統(tǒng)其他的.mk文件(系統(tǒng)定義的編譯規(guī)章)。

LOCAL_SRC_FILES-編譯的源文件

可以是.c,.cpp,.Java,.S(匯編文件)或是.aidl等格式

不同的文件用空格隔開。假如編譯名目子名目，采納相對路徑，如子名目/文件名。也可以通過$(call名目)，指明編譯某名目

下全部.c/.cpp/.java/.S/.aidl文件.追加文件LOCAL_SRC_FILES+=文件

LOCAL_C_INCLUDES-需要包含的頭文件名目

可以是系統(tǒng)定義路徑，也可以是相對路徑.如該編譯名目下有個include名目，寫法是include/*.h

LOCAL_SHARED_LIBRARIES-鏈接時需要的外部共享庫

LOCAL_STATIC_LIBRARIES-鏈接時需要的外部外部靜態(tài)

LOCAL_JAVA_LIBRARIES加入jar包

LOCAL_MODULE-編譯的目標對象

module是指系統(tǒng)的nativecode，通常針對c,c++代碼

./system/core/sh/Android.mk:32:LOCAL_MODULE:=sh

./system/core/libcutils/Android.mk:71:LOCAL_MODULE:=libcutils

./system/core/cpio/Android.mk:9:LOCAL_MODULE:=mkbootfs

./system/core/mkbootimg/Android.mk:8:LOCAL_MODULE:=mkbootimg

./system/core/toolbox/Android.mk:61:LOCAL_MODULE:=toolbox

./system/core/logcat/Android.mk:10:LOCAL_MODULE:=logcat

./system/core/adb/Android.mk:65:LOCAL_MODULE:=adb

./system/core/adb/Android.mk:125:LOCAL_MODULE:=adbd

./system/core/init/Android.mk:20:LOCAL_MODULE:=init

./system/core/vold/Android.mk:24:LOCAL_MODULE:=vold

./system/core/mountd/Android.mk:13:LOCAL_MODULE:=mountd

LOCAL_PACKAGE_NAME

Java應用程序的名字用該變量定義

./packages/apps/Music/Android.mk:9:LOCAL_PACKAGE_NAME:=Music

./packages/apps/Browser/Android.mk:14:LOCAL_PACKAGE_NAME:=Browser

./packages/apps/Settings/Android.mk:8:LOCAL_PACKAGE_NAME:=Settings

./packages/apps/Stk/Android.mk:10:LOCAL_PACKAGE_NAME:=Stk

./packages/apps/Contacts/Android.mk:10:LOCAL_PACKAGE_NAME:=Contacts

./packages/apps/Mms/Android.mk:8:LOCAL_PACKAGE_NAME:=Mms

./packages/apps/Camera/Android.mk:8:LOCAL_PACKAGE_NAME:=Camera

./packages/apps/Phone/Android.mk:11:LOCAL_PACKAGE_NAME:=Phone

./packages/apps/VoiceDialer/Android.mk:8:LOCAL_PACKAGE_NAME:=VoiceDialer

BUILD_SHARED_LIBRARY-指明要編譯成動態(tài)庫。

編譯的目標，用include操作符

UILD_STATIC_LIBRARY來指明要編譯成靜態(tài)庫。

假如是java文件的話，會用到系統(tǒng)的編譯腳本host_java_library.mk，用BUILD_PACKAGE來指明。三個編譯

include$(BUILD_STATIC_LIBRARY)

BUILD_STATIC_LIBRARY:=$(BUILD_SYSTEM)/static_library.mk

include$(BUILD_SHARED_LIBRARY)

./build/core/config.mk:50:BUILD_SHARED_LIBRARY:=$(BUILD_SYSTEM)/shared_library.mk

include$(BUILD_HOST_SHARED_LIBRARY)

BUILD_HOST_SHARED_LIBRARY:=$(BUILD_SYSTEM)/host_shared_library.mk

include$(BUILD_EXECUTABLE)

build/core/config.mk:51:BUILD_EXECUTABLE:=$(BUILD_SYSTEM)/executable.mk

include$(BUILD_HOST_EXECUTABLE)

./build/core/config.mk:53:BUILD_HOST_EXECUTABLE:=$(BUILD_SYSTEM)/host_executable.mk

BUILD_HOST_JAVA_LIBRARY:=$(BUILD_SYSTEM)/host_java_library.mk

BUILD_JAVA_LIBRARY

./build/core/config.mk:58:BUILD_JAVA_LIBRARY:=$(BUILD_SYSTEM)/java_library.mk

BUILD_STATIC_JAVA_LIBRARY編譯靜態(tài)JAVA庫

./build/core/config.mk:59:BUILD_STATIC_JAVA_LIBRARY:=$(BUILD_SYSTEM)/static_java_library.mk

BUILD_HOST_JAVA_LIBRARY編譯本機用的JAVA庫

./build/core/config.mk:60:BUILD_HOST_JAVA_LIBRARY:=$(BUILD_SYSTEM)/host_java_library.mk

BUILD_HOST_STATIC_LIBRARY:=$(BUILD_SYSTEM)/host_static_library.mk

BUILD_HOST_SHARED_LIBRARY:=$(BUILD_SYSTEM)/host_shared_library.mk

BUILD_STATIC_LIBRARY:=$(BUILD_SYSTEM)/static_library.mk

BUILD_RAW_STATIC_LIBRARY:=$(BUILD_SYSTEM)/raw_static_library.mk

BUILD_SHARED_LIBRARY:=$(BUILD_SYSTEM)/shared_library.mk

BUILD_EXECUTABLE:=$(BUILD_SYSTEM)/executable.mk

BUILD_RAW_EXECUTABLE:=$(BUILD_SYSTEM)/raw_executable.mk

BUILD_HOST_EXECUTABLE:=$(BUILD_SYSTEM)/host_executable.mk

BUILD_PACKAGE:=$(BUILD_SYSTEM)/package.mk

BUILD_HOST_PREBUILT:=$(BUILD_SYSTEM)/host_prebuilt.mk

BUILD_PREBUILT:=$(BUILD_SYSTEM)/prebuilt.mk

BUILD_MULTI_PREBUILT:=$(BUILD_SYSTEM)/multi_prebuilt.mk

BUILD_JAVA_LIBRARY:=$(BUILD_SYSTEM)/java_library.mk

BUILD_STATIC_JAVA_LIBRARY:=$(BUILD_SYSTEM)/static_java_library.mk

BUILD_HOST_JAVA_LIBRARY:=$(BUILD_SYSTEM)/host_java_library.mk

BUILD_DROIDDOC:=$(BUILD_SYSTEM)/droiddoc.mk

BUILD_COPY_HEADERS:=$(BUILD_SYSTEM)/copy_headers.mk

BUILD_KEY_CHAR_MAP:=$(BUILD_SYSTEM)/key_char_map.mk

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

LOCAL_PRELINK_MODULE

Prelink利用事先鏈接代替運行時鏈接的方法來加速共享庫的加載，它不僅可以加快起動速度，還可以削減部分內(nèi)存開銷，

是各種Linux架構(gòu)上用于削減程序加載時間、縮短系統(tǒng)啟動時間和加快應用程序啟動的很受歡迎的一個工具。程序運行時的

動態(tài)鏈接尤其是重定位(relocation)的開銷對于大型系統(tǒng)來說是很大的。

動態(tài)鏈接和加載的過程開銷很大，并且在大多數(shù)的系統(tǒng)上,函數(shù)庫并不會經(jīng)常被更動,每次程序被執(zhí)行時所進行的鏈接

動作都是完全相同的，對于嵌入式系統(tǒng)來說尤其如此。因此，這一過程可以改在運行時之前就可以預先處理好，即花一些時間

利用Prelink工具對動態(tài)共享庫和可執(zhí)行文件進行處理，修改這些二進制文件并加入相應的重定位等信息，節(jié)省了原來在程序

啟動時的比較耗時的查詢函數(shù)地址等工作，這樣可以削減程序啟動的時間，同時也削減了內(nèi)存的耗用。

Prelink的這種做法當然也有代價：每次更新動態(tài)共享庫時，相關的可執(zhí)行文件都需要重新執(zhí)行一遍Prelink才能保

證有效，由于新的共享庫中的符號信息、地址等很可能與原來的已經(jīng)不同了，這就是為什么androidframework代碼一改動，

這時候就會導致相關的應用程序重新被編譯。

這種代價對于嵌入式系統(tǒng)的開發(fā)者來說可能略微帶來一些冗雜度，不過好在對用戶來說幾乎是可以忽視的。

變量設置為false那么將不做prelink操作

LOCAL_PRELINK_MODULE:=false

默認是需要prlink的，同時需要在build/core/prelink-linux-arm.map中加入

libhellod.so0x96000000

這個map文件似乎是制定動態(tài)庫的地址的，在前面解釋上面有一些地址范圍的信息，留意庫與庫之間的間隔數(shù)，

假如指定不好的話編譯的時候會提示說地址空間沖突的問題。另外，留意排序，這里要把數(shù)大的放到前面去，

根據(jù)大小降序排序。

解析LOCAL_PRELINK_MODULE變量

build/core/dynamic_binary.mk:94:ifeq($(LOCAL_PRELINK_MODULE),true)

ifeq($(LOCAL_PRELINK_MODULE),true)

$(prelink_output):$(prelink_input)$(TARGET_PRELINKER_MAP)$(APRIORI)

$(transform-to-prelinked)

transform-to-prelinked定義：

./build/core/definitions.mk:1002:definetransform-to-prelinked

definetransform-to-prelinked

@mkdir-p$(dir$@)

@echotargetPrelink:$(PRIVATE_MODULE)($@)

$(hide)$(APRIORI)/

--prelinkmap$(TARGET_PRELINKER_MAP)/

--locals-only/

--quiet/

$/build/tools/apriori

參考文檔：

動態(tài)庫優(yōu)化--Prelink(預連接)技術

http://./article/09-04/71629s.html

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

LOCAL_ARM_MODE:=arm

目前Android大部分都是基于Arm處理器的，Arm指令用兩種模式Thumb(每條指令兩個字節(jié))和arm指令(每條指令四個字節(jié))

LOCAL_CFLAGS+=-O3-fstrict-aliasing-fprefetch-loop-arrays

通過設定編譯器操作，優(yōu)化級別，-O0表示沒有優(yōu)化,-O1為缺省值，-O3優(yōu)化級別最高

LOCAL_CFLAGS+=-W-Wall

LOCAL_CFLAGS+=-fPIC-DPIC

LOCAL_CFLAGS+=-O2-g-DADB_HOST=1-Wall-Wno-unused-parameter

LOCAL_CFLAGS+=-D_XOPEN_SOURCE-D_GNU_SOURCE-DSH_HISTORY

LOCAL_CFLAGS+=-DUSEOVERLAY2

依據(jù)條件選擇相應的編譯參數(shù)

ifeq($(TARGET_ARCH),arm)

LOCAL_CFLAGS+=-DANDROID_GADGET=1

LOCAL_CFLAGS:=$(PV_CFLAGS)

endif

ifeq($(TARGET_BUILD_TYPE),release)

LOCAL_CFLAGS+=-O2

endif

LOCAL_LDLIBS:=-lpthread

LOCAL_LDLIBS+=-ldl

ifdefUSE_MARVELL_MVED

LOCAL_WHOLE_STATIC_LIBRARIES+=lib_il_mpeg4aspdecmved_wmmx2lnxlib_il_h264decmved_wmmx2lnx

LOCAL_SHARED_LIBRARIES+=libMrvlMVED

else

LOCAL_WHOLE_STATIC_LIBRARIES+=lib_il_h264dec_wmmx2lnxlib_il_mpeg4aspdec_wmmx2lnx

endif

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

其他一些變量和腳本：

HOST_JNILIB_SUFFIX

LOCAL_MODULE_SUFFIX

LOCAL_MODULE_SUFFIX:=$(HOST_JNILIB_SUFFIX)

HOST_GLOBAL_LDFLAGS

TARGET_GLOBAL_LDFLAGS

PRIVATE_LDFLAGS

LOCAL_LDLIBS

LOCAL_C_INCLUDES

LOCAL_STATIC_LIBRARIES

LOCAL_STATIC_LIBRARIES+=codecJPDec_WMMX2LNXmiscGen_WMMX2LNX

LOCAL_SHARED_LIBRARIES

LOCAL_SHARED_LIBRARIES+=libMrvlIPP

LOCAL_SHARED_LIBRARIES+=$(common_SHARED_LIBRARIES)

LOCAL_SHARED_LIBRARIES+=libMrvlIPP

LOCAL_SHARED_LIBRARIES+=libdl

ifeq($(TARGET_PRODUCT),littleton)

LOCAL_C_INCLUDES+=vendor/marvell/littleton/m2d/

LOCAL_SHARED_LIBRARIES+=libOmxCore

endif

vendor/marvell/littleton/littleton.mk:27:PRODUCT_NAME:=littleton

vendor/marvell/littleton/littleton.mk:28:PRODUCT_DEVICE:=littleton

vendor/marvell/littleton/AndroidProducts.mk:13:$(LOCAL_DIR)/littleton.mk

vendor/sample/products/sample_addon.mk:40:PRODUCT_NAME:=sample_addon

vendor/htc/dream-open/htc_dream.mk:6:PRODUCT_NAME:=htc_dream

./vendor/htc/dream-open/htc_dream.mk:7:PRODUCT_DEVICE:=dream-open

./vendor/htc/dream-open/AndroidProducts.mk:3:$(LOCAL_DIR)/htc_dream.mk

build/target/product/generic.mk:26:PRODUCT_NAME:=generic

build/target/product/generic_with_google.mk:20:PRODUCT_NAME:=generic_with_google

build/target/product/min_dev.mk:6:PRODUCT_NAME:=min_dev

build/target/product/core.mk:2:PRODUCT_NAME:=

build/target/product/sim.mk:7:PRODUCT_NAME:=sim

build/target/product/sdk.mk:37:PRODUCT_NAME:=sdk

build/tools/buildinfo.sh:20:echo=$PRODUCT_NAME

lunchsample_addon-eng

lunchhtc_dream-eng

lunchgeneric-eng

lunch1

lunchsim-eng

TARGET_BUILD_TYPE=release

lunch2

TARGET_BUILD_TYPE=debug

lunchgeneric-user

.PHONY:systemtarball-nodeps

systemtarball-nodeps:$(FS_GET_STATS)/

$(filter-outsystemtarball-nodepsstnod,$(MAKECMDGOALS))

$(build-systemtarball-target)

.PHONY:stnod

stnod:systemtarball-nodeps

systemimage-nodepssnod

./core/main.mk:BUILD_SYSTEM:=$(TOPDIR)build/core

./core/main.mk:include$(BUILD_SYSTEM)/config.mk

./core/main.mk:include$(BUILD_SYSTEM)/cleanbuild.mk

./core/main.mk:include$(BUILD_SYSTEM)/version_defaults.mk

./core/main.mk:include$(BUILD_SYSTEM)/definitions.mk

./core/main.mk:include$(BUILD_SYSTEM)/Makefile

./core/static_java_library.mk:include$(BUILD_SYSTEM)/java_library.mk

./core/host_java_library.mk:include$(BUILD_SYSTEM)/base_rules.mk

./core/executable.mk:include$(BUILD_SYSTEM)/dynamic_binary.mk

./core/java_library.mk:include$(BUILD_SYSTEM)/java.mk

./core/binary.mk:include$(BUILD_SYSTEM)/base_rules.mk

./core/raw_executable.mk:include$(BUILD_SYSTEM)/binary.mk

./core/prebuilt.mk:include$(BUILD_SYSTEM)/base_rules.mk

./core/host_executable.mk:include$(BUILD_SYSTEM)/binary.mk

./core/combo/select.mk:$(combo_target)PRELINKER_MAP:=$(BUILD_SYSTEM)/prelink-$(combo_os_arch).map

./core/shared_library.mk:include$(BUILD_SYSTEM)/dynamic_binary.mk

./core/config.mk:include$(BUILD_SYSTEM)/pathmap.mk

./core/config.mk:BUILD_COMBOS:=$(BUILD_SYSTEM)/combo

./core/config.mk:CLEAR_VARS:=$(BUILD_SYSTEM)/clear_vars.mk

./core/config.mk:BUILD_HOST_STATIC_LIBRARY:=$(BUILD_SYSTEM)/host_static_library.mk

./core/config.mk:BUILD_HOST_SHARED_LIBRARY:=$(BUILD_SYSTEM)/host_shared_library.mk

./core/config.mk:BUILD_STATIC_LIBRARY:=$(BUILD_SYSTEM)/static_library.mk

./core/config.mk:BUILD_RAW_STATIC_LIBRARY:=$(BUILD_SYSTEM)/raw_static_library.mk

./core/config.mk:BUILD_SHARED_LIBRARY:=$(BUILD_SYSTEM)/shared_library.mk

./core/config.mk:BUILD_EXECUTABLE:=$(BUILD_SYSTEM)/executable.mk

./core/config.mk:BUILD_RAW_EXECUTABLE:=$(BUILD_SYSTEM)/raw_executable.mk

./core/config.mk:BUILD_HOST_EXECUTABLE:=$(BUILD_SYSTEM)/host_executable.mk

./core/config.mk:BUILD_PACKAGE:=$(BUILD_SYSTEM)/package.mk

./core/config.mk:BUILD_HOST_PREBUILT:=$(BUILD_SYSTEM)/host_prebuilt.mk

./core/config.mk:BUILD_PREBUILT:=$(BUILD_SYSTEM)/prebuilt.mk

./core/config.mk:BUILD_MULTI_PREBUILT:=$(BUILD_SYSTEM)/multi_prebuilt.mk

./core/config.mk:BUILD_JAVA_LIBRARY:=$(BUILD_SYSTEM)/java_library.mk

./core/config.mk:BUILD_STATIC_JAVA_LIBRARY:=$(BUILD_SYSTEM)/static_java_library.mk

./core/config.mk:BUILD_HOST_JAVA_LIBRARY:=$(BUILD_SYSTEM)/host_java_library.mk

./core/config.mk:BUILD_DROIDDOC:=$(BUILD_SYSTEM)/droiddoc.mk

./core/config.mk:BUILD_COPY_HEADERS:=$(BUILD_SYSTEM)/copy_headers.mk

./core/config.mk:BUILD_KEY_CHAR_MAP:=$(BUILD_SYSTEM)/key_char_map.mk

./co