rooting the droid (Motorola A855) rooted

By thomas, 10 December, 2009
This is my first android phone, so I thought I'd share my experience of rooting the phone. All credit to Zinx Verituse over on Alldroid.org

Note: I just updated to the update released December 10th for the droid and was able to reapply the update.zip.

The instructions are here

  • Download this file and rename it update.zip on the sdcard.
  • turn off the phone
  • turn on the phone holding down the x key on the keyboard
  • When you see the Motorola symbol, press Vol+ and Camera buttons together.
  • An onscreen menu will appear, use the d-pad to navigate to update.zip and type return to apply
  • After the phone reboots, Go to Settings -> Applications -> Development and enable USB Debugging
  • Connect the droid to your desktop, download the sdk
  • unpack the sdk and navigate to tools directory
  • as root/administrator run adb start-server
  • next run adb shell
  • su to root /system/bin/su
  • remount the root filesystem rw
    # mount rootfs / rootfs ro 0 0 tmpfs /dev tmpfs rw,mode=755 0 0 devpts /dev/pts devpts rw,mode=600 0 0 proc /proc proc rw 0 0 sysfs /sys sysfs rw 0 0 tmpfs /sqlite_stmt_journals tmpfs rw,size=4096k 0 0 none /dev/cpuctl cgroup rw,cpu 0 0 /dev/block/mtdblock4 /system yaffs2 ro 0 0 /dev/block/mtdblock6 /data yaffs2 rw,nosuid,nodev 0 0 /dev/block/mtdblock5 /cache yaffs2 rw,nosuid,nodev 0 0 /dev/block/mtdblock0 /config yaffs2 ro 0 0 /dev/block//vold/179:1 /sdcard vfat rw,dirsync,nosuid,nodev,noexec,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0 # mount -o remount -o rw -t yaffs2 /dev/block/mtdblock4 /system
    I don't know if the device will always be the same (/dev/block/mtdblock4), best to check first.
  • now make a copy of sh and call it su-something or replace su
    # cd /system/bin # cat sh > su or # cat sh >su-fake # chmod 4775 su or # chmod 4775 su-fake # exit
You now have either su or su-fake that you can run from terminal emulator on the phone and become root. To start using your new privileges, install busybox and symlink to it for all the tools that are missing...