MTK6577---adb shell默认root登陆

一. 原理
原理很简单就是将/default.prop文件中的ro.secure=1 改为ro.secure=0

root@android:/ # cat /default.prop
#
# ADDITIONAL_DEFAULT_PROPERTIES
#
ro.mh.product=a_b_c
ro.mh.mtkversion=mt6577
ro.mh.intenational=false
ro.secure=0
ro.allow.mock.location=1
persist.mtk.aee.aed=on
ro.debuggable=1
persist.sys.usb.config=mass_storage,adb
persist.service.acm.enable=0

二. 解压并打包boot.img
为了将default.prop这个文件修改,得需要将boot.img解包,修改,然后再打包,
最后烧进系统就可以直接root登adb shell了,步骤如下:

//a.将解压出来的mkbootimg  repack-MT65xx.pl  unpack-MT65xx.pl这三个文件放在与boot.img同一个目录下
lsun@ubuntu:/work/bootimg$ ls
boot.img  mkbootimg  repack-MT65xx.pl  unpack-MT65xx.pl

//b.解压boot.img
sun@ubuntu:/work/bootimg$ ./unpack-MT65xx.pl ./boot.img
MTK-Tools by Bruno Martins
MT65xx unpack script (last update: 31-07-2012)
Valid Android signature found...
Kernel written to ./boot.img-kernel.img
Ramdisk written to ./boot.img-ramdisk.cpio.gz
Ramdisk size: 2108 blocks
Extracted ramdisk contents to directory ./boot.img-ramdisk
Successfully unpacked kernel and ramdisk.

//c.查看一下,多了boot.img-kernel.img 与 ramdisk的文件
sun@ubuntu:/work/bootimg$ ls
boot.img  boot.img-kernel.img  boot.img-ramdisk  boot.img-ramdisk.cpio.gz  mkbootimg  repack-MT65xx.pl  unpack-MT65xx.pl

//d.修改defautl.prop文件,使adb shell可以直接用root登陆
sun@ubuntu:/work/bootimg$ vi boot.img-ramdisk/default.prop

sun@ubuntu:/work/bootimg$ chmod 777 ./mkbootimg
//e.将boot.img打包
sun@ubuntu:/work/bootimg$ ./repack-MT65xx.pl -boot ./boot.img-kernel.img boot.img-ramdisk ./boot.img_new
MTK-Tools by Bruno Martins
MT65xx repack script (last update: 31-07-2012)
Repacking boot image...
Ramdisk size: 2108 blocks
Can't exec "mkbootimg": No such file or directory at ./repack-MT65xx.pl line 82.
Repacked boot image into ./boot.img_new

//f.找不到mkbootimg则修改repack-Mt65xx.pl
sun@ubuntu:/work/bootimg$ vi repack-MT65xx.pl
将system ("mkbootimg --kernel $kernel --ramdisk new-ramdisk-repack.cpio.gz -o $outfile");改为
system ("./mkbootimg --kernel $kernel --ramdisk new-ramdisk-repack.cpio.gz -o $outfile");

//g.重新打包boot.img
sun@ubuntu:/work/bootimg$ ./repack-MT65xx.pl -boot ./boot.img-kernel.img boot.img-ramdisk ./boot.img_new 
MTK-Tools by Bruno Martins
MT65xx repack script (last update: 31-07-2012)
Repacking boot image...
Ramdisk size: 2108 blocks
Repacked boot image into ./boot.img_new

//h.查看新生成的boot.img
sun@ubuntu:/work/bootimg$ ls
boot.img  boot.img-kernel.img  boot.img_new  boot.img-ramdisk  boot.img-ramdisk.cpio.gz  mkbootimg  repack-MT65xx.pl  unpack-MT65xx.pl

工具下载:
    mtk-tools.rar (下载后改名为: mtk-tools.tar.gz)