How to flash stock ROM using TWRP on Tecno Spark K7, leaving TWRP intact What are the right steps of flashing stock ROM using TWRP (Tecno Spark K7, Android 7.0 Nougat, TWRP v3.0.2), and still have TWRP Recovery on the phone, after the process.
I already have the phone backed up and have the stock ROM as a zip file.
you need a linux machine for converting sparse image into raw partition image  

sudo apt-get install android-tools-fsutils android-tools-adb android-tools-fastboot  
simg2img system.img system.ext4  


connect phone in twrp  

adb push system.ext4 /dev/block/bootdevice/by-name/system  


if file smaller than &lt; 4 GiB you can rename to system.emmc.win, copy to sdcard and restore from twrp directly, or manually restore from built-in terminal  

cat /external_sd/system.emmc.win &gt; /dev/block/bootdevice/by-name/system  


repeat this for vendor/odm (if exist). boot.img is already in raw format and can be renamed into boot.emmc.win directly  

your data and internal storage is maybe encrypted, if you want to backup you need to adb pull /dev/block/dm-0 or /dev/block/bootdevice/by-name/userdata + /dev/block/bootdevice/by-name/metadata
or
make twrp backup and adb pull -p -a /sdcard