居于mtk芯片安卓车机系统具体流程
一：车机系统框架
MCU 功能
电源控制
Radio 控制（RDS）
按键检测（Panel/Remote/SW）
常见信号检查(倒车/大灯/刹车)
CAN 模块通讯
ARM-MCU 通讯
进出碟控制
翻转马达系统
屏驱（此种情况倒车一般用 mcu 控制）
AMR 功能
wifi 、BT、 gps、3/4G
显示、触摸
多媒体播放（SD 卡、U 盘）
倒车显示
语音
AUX
胎压、DVR、CMMB
CVBS 输出（后排输出）
二：安卓启动流程
第一阶段：Android 设备上电后，首先会从处理器片上 ROM 的启动引导代码开始执行，片上 ROM 会寻找 Bootloader
代码，并加载到内存。（这一步由“芯片厂商”负责设计和实现）
第二阶段：Bootloader 开始执行，首先负责完成硬件的初始化，然后找到 Linux 内核代码，并加载到内存。（这一
步由“设备厂商”负责设计和实现）
第三阶段：Linux 内核开始启动，初始化各种软硬件环境，加载驱动程序，挂载根文件系统，并执行 init 程序，
由此开启 Android 的世界。（这一步则是 Android 内核开发过程中需要涉及的地方）
init 程序最核心的工作主要有 3 点：
（1） 创建和挂载一些系统目录/设备节点，设置权限，如：/dev, /proc, and /sys
（2） 解析 init.rc 和 init..rc，并启动属性服务，以及一系列的服务和进程。
（3） 显示 boot logo，默认是“Android”字样
第四阶段：Zygote 进程、SystemServer 进程创建 Zygote 进程由 init 进程创建，SystemServer 进程由 Zygote 创建
第五阶段：订制的service 启动：例举包括以下服务（ 添加的所有关键服务）
CBMService;
CanbusService;
McuService;
RadioService;
SettingService;
McuCBMService;
PandoraService;
SWCService;
第六阶段：启动完成阶段。当所有的服务都启动完毕后，SystemServer 会打印出“Making services ready”，然后
通过 ActivityManager 启动 Home 界面，并发送“ACTION_BOOT_COMPLETED”广播消息（到此真正看到了主界面）
三：代码结构
核心服务路径：\autochips\frameworks\base\services\java\com…
APP 路径：\autochips\packages
四：编译说明（AC8217平台代码而论）
全编译
1 . mbldenv.sh 导出编译需要的编译工具相关环境变量
2 . selfenv 拷贝 autochips 到相关目录主要拷贝以下目录：
3 . selfbuild
实际上 selfbuild 仅是 autochips\build\build.all 脚本的符号链接。在没有参数的情况下，selfbuild 会依次执行 build.env，
build.uboot，build.kernel，build.driver，build.arm2，build.android，build.otapackage，build.makeimage 这 7 个 sh 脚本。
相当分步执行以下：（当要单独编译部分时可以单独以下某句命令方法）
1. source./build.env设置编译环境2. ./selfbuild uboot 编译 uboot
3. ./selfbuilddriver编译ATC的driver4. ./selfbuild kernel 编译 linux kernel
5. ./selfbuildarm2编译arm26. ./selfbuild android 编译 android
7.$./selfbuild makeimage 生成最后需要烧写到板子上的 Image（ 把多余的 apk 删除同时打包镜像）
模块编译
1 : 用 mm 或 mmm 编译相应模块
2: . selfbuild makeimage 生产镜像
附上编译脚本片段代码：
**
mbldenv.sh脚本文件
**
!/bin/bash
#
ALPS(Android4.1 based) build environment profile setting
#
Overwrite JAVA_HOME environment variable setting if already exists
PATH=/mtktools/mtk-toolchain/gnuarm-4.2.1/image-tools: PATHPATH=/mtktools/mtk−toolchain/gnuarm−4.4.1/cross−tools/usr/local/bin: PATH
PATH=/mtktools/mtk-toolchain/vfp_4.5.1_2.6.27_cortex-a9-rhel4_002/i686/bin: PATHANTHOME=/usr/local/antexportANTHOMEexportMTKJAVAHOME=”/usr/local/jdk1.6.032”exportPATH= MTK_JAVA_HOME/bin: ANTHOME/bin: PATH
export ANDROID_JAVA_HOME= MTKJAVAHOMEexportANDROIDJAVATOOLCHAIN= MTK_JAVA_HOME/bin/
export JAVA_HOME= MTKJAVAHOMEexportJREHOME= {JAVA_HOME}/jre
export CLASSPATH=.: JAVAHOME/lib: {JRE_HOME}/lib
export PATH
unset USERNAME
SKIN1: SKIN2：
export SKIN=Skin2
selfenv脚本文件：
!/bin/sh
export ANDROID4=pwd
export ANDROID_SRC= ANDROID4exportKERNELSRC= ANDROID4/kernel
export KERNELDIR= KERNELSRC/exportAUTOCHIPSDIR= ANDROID4/autochips
export DRIVERS_DIR= AUTOCHIPSDIR/protect/platform/kernel/driversexportPUBLICDRIVERSDIR= AUTOCHIPS_DIR/platform/kernel/drivers
export DRIVERS_INC= AUTOCHIPSDIR/platform/kernel/drivers/incexportARM2SRC= AUTOCHIPS_DIR/platform/arm2
export DISPLAY_HARDWARE_INC= AUTOCHIPSDIR/hardware/atc/displayexportUBOOTSRC= AUTOCHIPS_DIR/platform/uboot
export SCRIPT_DIR= AUTOCHIPSDIR/buildexportANDROIDOUTPUT= ANDROID_SRC/out
export DRIVERS_OUTPUT= AUTOCHIPSDIR/platform/kernel/drivers/outputexportDRIVERSLIB= AUTOCHIPS_DIR/platform/kernel/drivers/lib
export AUTOCHIPS_TOOL= AUTOCHIPSDIR/toolsexportRELEASEFOLDERNAME= ANDROID4/image_release
export BOARD_CFG_FILE=$AUTOCHIPS_DIR/device/atc/ac8317/BoardConfig.mk
export PATH= ANDROIDSRC/autochips/external/gstreameraggregate/bin/: AUTOCHIPS_TOOL:$PATH
export JOB_NUM=grep processor /proc/cpuinfo |wc -l
export CHIP_VER=8317
find AUTOCHIPSDIR/device/atc/ac8317/.overlay/build/−typef|xargstouchcp−ruaf AUTOCHIPS_DIR/device/atc/ac8317/.overlay/build/* $ANDROID_SRC/build/
copy /autochips/kernel/includeto /kernel/include
find AUTOCHIPSDIR/kernel/include−typef|xargstouchcp−ruaf AUTOCHIPS_DIR/kernel/include/* $ANDROID_SRC/kernel/include/
INPUT_PARAM=$*
function check_parameter()
{
if [ ! -z “echo "$INPUT_PARAM" | grep eng” ];then
echo “eng”
elif [ ! -z “echo "$INPUT_PARAM" | grep userdebug” ];then
echo “userdebug”
elif [ ! -z “echo "$INPUT_PARAM" | grep user” ];then
echo “user”
else
echo “eng”
fi
}
retval=check_parameter $*
source ANDROIDSRC/build/envsetup.sh retval
INPUT_PARAM= INPUTPARAM/eng/INPUTPARAM= {INPUT_PARAM/userdebug/}
INPUT_PARAM= INPUTPARAM/user/INPUTPARAM= (echo $INPUT_PARAM)
lunch
if [ ! -z “echo "$INPUT_PARAM" | grep ?” ];then
lunch
else
lunch 5
fi
echo “env [$retval] setup completed!!!”
selfbuild脚本文件：
!/bin/sh
{
if [ -z which androidq ];then
#echo "no androidq, source bash_profile"
source ~/.bash_profile
source ~/.bashrc
fi
if [ ! -z which androidq ];then
echo “androidq ok, build with it”
ANDROIDQ=androidq
else
echo “no androidq, build without it”
ANDROIDQ=
fi
INPUT_PARA=$*
Copy Overlay folder to original
if [ ! -z “echo "$INPUT_PARA" | grep cpoverlay” ];then
SCRIPTDIR/build. INPUT_PARA
exit 0
fi
process android version: user, userdebug, eng
if [ ! -z “echo "$INPUT_PARA" | grep eng” ];then
export ANDROID_VER=eng
elif [ ! -z “echo "$INPUT_PARA" | grep userdebug” ];then
export ANDROID_VER=userdebug
elif [ ! -z “echo "$INPUT_PARA" | grep user” ];then
export ANDROID_VER=user
else
export ANDROID_VER=eng
fi
INPUT_PARA= INPUTPARA/eng/INPUTPARA= {INPUT_PARA/userdebug/}
INPUT_PARA= INPUTPARA/user/INPUTPARA= (echo $INPUT_PARA)
source autochips/build/build.env $ANDROID_VER
echo “export env: ANDROID4= ANDROID4”if[!−d AUTOCHIPS_DIR -o -z $AUTOCHIPS_DIR ];then
echo “export some env var error, exit”
exit 1
fi
ALLIMAGES=”uboot kernel driver arm2 android otapackage makeimage clean cts”
check if para is nand
if [ ! -z “echo "$INPUT_PARA" | grep nand” ];then
export AC83XX_BOOT_DEVICE=nand
elif [ ! -z “echo "$INPUT_PARA" | grep sd2” ];then
export AC83XX_BOOT_DEVICE=sd2
else
export AC83XX_BOOT_DEVICE=mmc
fi
remove mmc para
INPUT_PARA= INPUTPARA/nand/INPUTPARA= {INPUT_PARA/sd2/}
INPUT_PARA= (echo INPUT_PARA)
echo “AC83XX_BOOT_DEVICE :$AC83XX_BOOT_DEVICE”
check if it is release build, debug build by default
if [ ! -z “echo "$INPUT_PARA" | grep debug” ];then
export RELEASE_BUILD=false
echo “build for debug”
else
export RELEASE_BUILD=true
echo “build for release”
fi
remove release or debug if it has
INPUT_PARA={INPUT_PARA%release}
INPUT_PARA={INPUT_PARA%debug}
INPUT_PARA= (echo INPUT_PARA)
if [ -z “ INPUTPARA”];thenIMAGELIST=”ubootkerneldriverarm2androidotapackagemakeimage”exportBUILDALL=trueecho“noparam,default: IMAGE_LIST”
echo -e “\033[31m delete out( ANDROIDOUTPUT)folder?(y/n)\033[0m”read−t5RMOUTif[−dout−a“ RMOUT" = "y" -a " ?”=“0”];thenecho−e“\033[31mbegindeleteout( ANDROID_OUTPUT) folder\033[0m”
ANDROIDQrm−rf ANDROID_OUTPUT
fi
else
IMAGE_LIST=”$INPUT_PARA”
export BUILD_ALL=false
fi
if [ ! -z “echo $IMAGE_LIST | grep makeimage” ];then
export MAKE_IMAGE=true
IMAGE_LIST=${IMAGE_LIST%makeimage}
fi
for test
for PARAM in $IMAGE_LIST
do
if [ ! -z “echo "$ALLIMAGES" | grep $PARAM” ];then
if [ ! -z “echo $PARAM | grep android” ];then
if [ ! -z “echo $ANDROID_VER | grep eng” ];then
BUILD_PARA=”eng”
elif [ ! -z “echo $ANDROID_VER | grep userdebug” ];then
BUILD_PARA=”userdebug”
elif [ ! -z “echo $ANDROID_VER | grep user” ];then
BUILD_PARA=”user”
else
BUILD_PARA=””
fi
elif [ ! -z “echo $PARAM | grep kernel” ];then
if [ ! -z “echo "$RELEASE_BUILD" | grep false” ]; then
BUILD_PARA=”debug”
elif [ ! -z “echo $ANDROID_VER | grep eng” ];then
BUILD_PARA=”debug”
else
BUILD_PARA=””
fi
elif [ ! -z “echo $PARAM | grep driver” ];then
if [ ! -z “echo "$RELEASE_BUILD" | grep false” ]; then
BUILD_PARA=”debug”
else
BUILD_PARA=””
fi
else
BUILD_PARA=””
fi
echo -e "\033[32m build.$PARAM $BUILD_PARA\033[0m"
if [ ! -x $SCRIPT_DIR/build.$PARAM ];then
if [ ! -z "`echo $PARAM | grep otapackage`" ];then
source autochips/build/build.env $AC83XX_BOOT_DEVICE
fi
echo -e "\033[32m $SCRIPT_DIR/build.$PARAM $BUILD_PARA can't executable!\033[0m"
exit 1
fi
echo "++ build_dir is $SCRIPT_DIR, param is $PARAM, build_para is $BUILD_PARA++"
$ANDROIDQ $SCRIPT_DIR/build.$PARAM $BUILD_PARA
if [ "$?" != "0" ];then
echo -e "\033[31m build.$PARAM $BUILD_PARA error, stop!\033[0m"
exit 1
else
echo -e "\033[32m build.$PARAM $BUILD_PARA OK!\033[0m"
fi
else
echo -e “\033[31munknown cmd: $PARAM\033[0m”
fi
done
build kernel and driver again to debug if no release
assume that arm2 image is only need to generate in
building all iamge, which means the whole image building
if [ ! -z “echo "$RELEASE_BUILD" | grep false” ]; then
echo “it is debug build”
if [ ! -z “echo "$BUILD_ALL" | grep true” ]; then
echo “clean kernel and drivers”
cd KERNELDIR && make clean && make mrproper
#cdDRIVERS_DIR && make clean
echo “build kernel and driver again”
ANDROIDQ SCRIPT_DIR/build.kernel “debug”
ANDROIDQ SCRIPT_DIR/build.driver “debug”
fi
else
echo “it is release build”
fi
build image
if [ ! -z “echo $MAKE_IMAGE | grep true” ];then
echo “Going to build images”
$SCRIPT_DIR/build.makeimage
fi
echo “build is done!”
exit
} | tee buildlog.txt