Download latest Android 4.4.4 KitKat firmware for Xiaomi Mi2 & Mi2S smartphones from here or from here. Download GF firmware version from here or here. Download previous firmware from here.
Archive name: XIAOMI_M2_M2S_V6_4.4.4_20160327
Archive file size: 623 MB / 370 MB
Image: XIAOMI_M2_M2S_V6_SJJL_4.4.4_ROM_20160327A / XIAOMI_M2_M2S_V6_SJJL_4.4.4_ROM_20160327B / XIAOMI_2A_MIUI_V6_SJJL_ROM_20160327GF
Model: Xiaomi Mi2 & Mi2S smartphones
Platform: Qualcomm Snapdragon S4 / Snapdragon 600
Build number: aries-user 4.4.4 KTU84P 5.4.4 release-keys
Caution: Please do not update firmware unless you know what you are doing, you really want it or it is absolutely necessary. Firmware updates may occasionally have bad results, like bricking your device, temporarily or permanently. The firmware update process is done entirely at your own risk. Before attempting to update the firmware, back up your data.