ALPS e1901_v77_jbl_hd_rtw

dear all, please help to root my china mobile phone. thnks.

Star S7500
Model number: e1901_v77_jbl_hd_rtw
CPU: MT6577
CPU model: ARMv7 Processor rev 0 (v7l)
Android 4.1.1
Build number: e1901_v77_jbl_hd_rtw_20130311