Android内核编译（支持netfilter/iptalbes）(can't initialize iptables table `filter': iptables who)

Android模拟器默认内核不支持netfilter，所以试图使用iptalbes时，会出现错误。

# iptables -L
iptables -L
iptables v1.3.7: can't initialize iptables table `filter': iptables who? (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.
#

解决方法是重新编译一个android内核，编译的时候打开netfilter相关模块，用新内核替换原有内核即可。

实验环境：ubuntu10.04 64bit

下载适用模拟器的android内核代码

root@ubuntu:~/android/kernel# git clone https://android.googlesource.com/kernel/goldfish.git
Initialized empty Git repository in /home/shanks/android/kernel/goldfish/.git/
remote: Counting objects: 28280, done
remote: Finding sources: 100% (6/6)
remote: Getting sizes: 100% (5/5)
remote: Compressing objects: 100% (5/5)
Receiving objects: 100% (2442118/2442118), 499.20 MiB | 772 KiB/s, done.
remote: Total 2442118 (delta 2048586), reused 2442116 (delta 2048586)
Resolving deltas: 100% (2048602/2048602), done.

查看可用版本

root@ubuntu:~/android/kernel/goldfish# git branch -a
* master
  remotes/origin/HEAD -> origin/master
  remotes/origin/android-goldfish-2.6.29
  remotes/origin/android-goldfish-3.4
  remotes/origin/linux-goldfish-3.0-wip
  remotes/origin/master

下载2.6.29版本。

root@ubuntu:~/android/kernel/goldfish# git checkout remotes/origin/android-goldfish-2.6.29
Checking out files: 100% (26821/26821), done.
Note: checking out 'remotes/origin/android-goldfish-2.6.29'.

下载完成后，设置编译所需环境变量。

root@ubuntu:~/android/kernel/goldfish# export ARCH=arm
root@ubuntu:~/android/kernel/goldfish# export SUBARCH=arm
root@ubuntu:~/android/kernel/goldfish# export CROSS_COMPILE=arm-eabi-
root@ubuntu:~/android/kernel/goldfish# export PATH=<PWD>/prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin:$PATH

运行make

make goldfish_defconfig

接下来配置编译的模块，这个过程可能会报缺少一些必要的包，可以提前安装相关的包，也可以根据错误逐步添加。

root@ubuntu:~/android/kernel/goldfish# apt-get install ia32-libs

下面是实验过程记录。

root@ubuntu:~/android/kernel/goldfish# make menuconfig
 *** Unable to find the ncurses libraries or the
 *** required header files.
 *** 'make menuconfig' requires the ncurses libraries.
 *** 
 *** Install ncurses (ncurses-devel) and try again.
 *** 
make[1]: *** [scripts/kconfig/dochecklxdialog] Error 1
make: *** [menuconfig] Error 2


root@ubuntu:~/android/kernel/goldfish# apt-get install libncurses-dev
Reading package lists... Done
Building dependency tree       
Reading state information... Done

再运行make menuconfig，选择相关模块。

配置完成后，进行编译

root@ubuntu:~/android/kernel/goldfish# make -j4
make: arm-eabi-gcc: Command not found
  CHK     include/linux/version.h
make[1]: `include/asm-arm/mach-types.h' is up to date.
  CHK     include/linux/utsrelease.h
  SYMLINK include/asm -> include/asm-arm
  CC      scripts/mod/empty.o
/bin/sh: arm-eabi-gcc: not found
make[2]: *** [scripts/mod/empty.o] Error 127
make[1]: *** [scripts/mod] Error 2
make: *** [scripts] Error 2

root@ubuntu:~/android/kernel/goldfish# apt-get install lib32ncurses5-dev

root@ubuntu:~/android/kernel/goldfish# make -j4
  CHK     include/linux/version.h
  SYMLINK include/asm -> include/asm-arm
make[1]: `include/asm-arm/mach-types.h' is up to date.
  CHK     include/linux/utsrelease.h
  CC      scripts/mod/empty.o
.../prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/../lib/gcc/arm-eabi/4.4.3/../../../../arm-eabi/bin/as: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory
make[2]: *** [scripts/mod/empty.o] Error 1
make[1]: *** [scripts/mod] Error 2
make: *** [scripts] Error 2
root@ubuntu:~/android/kernel/goldfish# apt-get install ia32-libs


  OBJCOPY arch/arm/boot/zImage
  Kernel: arch/arm/boot/zImage is ready

编译完成后，使用新内核运行模拟器。

...\tools>emulator.exe -avd CM2.3 -kernel ....\zImage -show-kernel -no-snapshot
serial0 console
Uncompressing Linux......................................................... done, booting the kernel.
Initializing cgroup subsys cpu
Linux version 2.6.29-gcb06bef (root@ubuntu) (gcc version 4.4.3 (GCC) ) #1 Thu Nov 8 01:35:29 PST 2012
CPU: ARM926EJ-S [41069265] revision 5 (ARMv5TEJ), cr=00093177
CPU: VIVT data cache, VIVT instruction cache  

问题得以解决

参考：
http://source.android.com/source/building-kernels.html
http://blog.csdn.net/fdl19881/article/details/7467129