[Galaxy Grand 2 General] mobihack:
So I had a look and this is what I found:

1) Mounts /system and /hidden as /preload and checks ro.build.fingerprint

2) Update checks for patches applied to system apps using md5 hash. If patch is applied, update is cancelled.

Ie. If system apps are modified, no update for you!

3) Deletes:

"/system/app/Drive.apk", "/system/csc/BNG/",

"/system/csc/BNG/csc_contents/",

"/system/csc/BNG/csc_contents/enforceskippingpackages.txt",

"/system/csc/BNG/system/", "/system/csc/BNG/system/csc/",

"/system/csc/BNG/system/csc/contents.db",

"/system/csc/BNG/system/csc/customer.xml",

"/system/csc/BNG/system/csc/others.xml",

"/system/csc/BNG/system/csc/sales_code.dat",

"/system/csc/BNG/system/etc/",

"/system/csc/BNG/system/etc/csc_apks_list_BNG.txt",

"/system/csc/BNG/system/etc/csc_ringtones_list_BNG.txt",

"/system/csc/BNG/system/etc/hidden_apks_list_BNG.txt",

"/system/csc/contents.db", "/system/csc/customer.xml",

"/system/csc/others.xml", "/system/csc/sales_code.dat",

"/system/etc/Bluetooth_cal.acdb",

"/system/etc/General_cal.acdb", "/system/etc/Global_cal.acdb",

"/system/etc/Handset_cal.acdb", "/system/etc/Hdmi_cal.acdb",

"/system/etc/Headset_cal.acdb", "/system/etc/Speaker_cal.acdb",

"/system/etc/snd_soc_msm/snd_soc_msm_Tapan",

"/system/lib/libcrashreporter.so",

"/system/lib/libfilterframework_jni.so",

"/system/lib/libgcastv2_base.so",

"/system/lib/libgcastv2_support.so",

"/system/lib/libgoogle_hotword_jni.so",

"/system/lib/libjgcastservice.so",

"/system/lib/libmoviemaker-jni.so", "/system/lib/libnetjni.so",

"/system/lib/libpatts_engine_jni_api_ub.so",

"/system/lib/libphotoeditor_native.so",

"/system/usr/srec/en-US/commands.abnf",

"/system/usr/srec/en-US/dnn",

"/system/usr/srec/en-US/hclg_shotword",

"/system/usr/srec/en-US/hmm_symbols",

"/system/usr/srec/en-US/hmmlist",

"/system/usr/srec/en-US/hotword.config",

"/system/usr/srec/en-US/hotword_classifier",

"/system/usr/srec/en-US/hotword_normalizer",

"/system/usr/srec/en-US/hotword_prompt.txt",

"/system/usr/srec/en-US/hotword_word_symbols",

"/system/usr/srec/en-US/phone_state_map",

"/system/usr/srec/en-US/wordlist", "/system/CSCVersion.txt",

"/system/app/GoogleTTS.apk",

"/system/etc/secure_storage/.system.bin.wpa_supplicant/ss_id",

"/system/etc/secure_storage/ss_config",

"/system/lib/libPowerStretch.so",

"/system/usr/srec/en-US/metadata",

"/system/app/GoogleDrive.apk", "/system/lib/libRSSupport.so",

"/system/lib/libpatts_engine_jni_api.so",

"/system/lib/libplus_jni_v8.so",

"/system/lib/librs.antblur.so",

"/system/lib/librs.antblur_constant.so",

"/system/lib/librs.antblur_drama.so",

"/system/lib/librs.drama.so", "/system/lib/librs.film_base.so",

"/system/lib/librs.fixedframe.so", "/system/lib/librs.grey.so",

"/system/lib/librs.image_wrapper.so",

"/system/lib/librs.retrolux.so", "/system/lib/librsjni.so",

"/system/usr/srec/en-US/acoustic_model",

"/system/usr/srec/en-US/embed_phone_nn_model",

"/system/usr/srec/en-US/embed_phone_nn_state_sym",

"/system/usr/srec/en-US/google_hotword.config",

"/system/usr/srec/en-US/google_hotword_clg",

"/system/usr/srec/en-US/google_hotword_logistic",

"/system/usr/srec/en-US/hmmsyms",

"/system/usr/srec/en-US/hotword_symbols",

"/system/usr/srec/en-US/lintrans_model",

"/system/usr/srec/en-US/symbols",

"/system/recovery.img"

4) Extracts and updates many files

5) boot.img is updated

6) Sets appropriate permissions

That's it

Sent from my SM-G7102