Modding emmc with ufi box and root the system manual
BTW, I just saw some people post on a chinese forum, link below:
https://tieba.baidu.com/p/6536366728?pn=1
The poster have a SONY BRAVIA 65X8500G Chinese version(x850G in US), running Android TV 9.0 but no GSM, no youtube, no netflix,no Alexa nor Airplay2.
So they want to root the TV and add the GSM and Airplay. or even more.
The poster did not say much how he do that, but as we can see from the photo, he root it and modify the firmware with other regional firmware.
I find some resualt in his other thread that he flash different firmware on his chinese version 65X8500G hardware.
China Frimware (cna)(1603610100): boot normally, works fine
China Frimware(cna)(1603590100)(downgrade): boot normally, works fine
US Frimware(naa)(1603598100): boot normally, can't finish initial setup wizard
EU Frimware(eua)(1603598100): black screen after SONY logo,can't enter the system
Ph Frimware(laa)(1603598100): black screen after SONY logo,can't enter the system
Japan Frimware(jpa)(1603598100): black screen after SONY logo,can't enter the system
APAC (paa): no android 9 firmare yet
HK (hka): no android 9 firmare yet
TW (twa): no android 9 firmare yet
Here is how he root the tv
1. use A male -A male USB Cable physical contect the PC and TV,using adb to enter the fastboot mode, unlock bootload, there is no code needed.
after you enter the fastboot mode, all the button combinations are invalid,if anything goes wrong, noway to fix it by yourself.
1a. after unlock, disable the verify boot
1b. there is anti rollback,ab slot, you can not boot the slot with low firmware version, change the vb index, you can bypass the anti rollback
2. you can use Magisk to root it now.
3. after root the TV you can use Magisk to patch the boot,and flash it under recovery mode. Do NOT wipe data, otherwise you will have bootanimation loop.
4. do not forget set_active/setActiveBootSlot after you flash the boot, also reset retry count and unmark curent slot successful mark
I am not an Android developer, I just try to translate the Chinese into English.
Hope someone can understand this, and make it more easier for people to root their Sony bravia android TV.