Android6.0内核移植（2）：kernel编译内核

普通步骤是：用来编译整个Android源码

source build/envsetup.sh
lunch sabresd_6dq-user
make -j20

不过每次这样太繁琐，下面来单独编译kernel分析：在上面make之后的日志中

No private recovery resources for TARGET_DEVICE sabresd_6dq
make -C kernel_imx imx_v7_android_defconfig ARCH=arm CROSS_COMPILE=`pwd`/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9/bin/arm-linux-androideabi- LOADADDR=0x10008000 KCFLAGS=-mno-android   //编译生成zImage
make[1]: Entering directory `/home/hejin/myandroid/kernel_imx'
#
# configuration written to .config
#
make[1]: Leaving directory `/home/hejin/myandroid/kernel_imx'
install -D kernel_imx/.config out/target/product/sabresd_6dq/.config
make -C kernel_imx -j20 uImage ARCH=arm CROSS_COMPILE=`pwd`/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9/bin/arm-linux-androideabi- LOADADDR=0x10008000 KCFLAGS=-mno-android   //编译生成uImage
make[1]: Entering directory `/home/hejin/myandroid/kernel_imx'
scripts/kconfig/conf  --silentoldconfig Kconfig
make[1]: Leaving directory `/home/hejin/myandroid/kernel_imx'
make[1]: Entering directory `/home/hejin/myandroid/kernel_imx'
  CHK     include/config/kernel.release
  CHK     include/generated/uapi/linux/version.h
  CC      scripts/mod/empty.o
  CC      scripts/mod/devicetable-offsets.s
  MKELF   scripts/mod/elfconfig.h

编译：

　1. 根据上面导出环境变量

  export ARCH=arm
  export CROSS_COMPILE=~/myandroid/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9/bin/arm-linux-androideabi-

2. 编译
make savedefconfig     //将当前的.config生成defconfig
make imx_v7_android_defconfig   //重新生成.config
echo $CROSS_COMPILE        
//make all -j20 >> ~/debug.txt     //生成zImage
make -j20 uImage LOADADDR=0x10008000 KCFLAGS=-mno-android    //生成uImage，暂时不清楚为何

 接着编译bootimg (uImagel 和ramdisk)：

source build/envsetup.sh 
lunch sabresd_6dq-user
make bootimage