| Partition Name | Description | File Type (SP Flash Tool) | | :--- | :--- | :--- | | | Bootloader for MTK chips. DO NOT UNCHECK this, but handle with care. | preloader_a37m.bin | | NVRAM | Stores IMEI, Wi-Fi MAC, Bluetooth addresses. | NVRAM | | Boot Image | Kernel and ramdisk. | boot.img | | Recovery | Stock recovery (replaces TWRP if installed). | recovery.img | | System | The Android OS (usually Lollipop 5.1 or Marshmallow 6.0). | system.img | | Userdata | Factory reset data. | userdata.img | | Cache | Temporary system files. | cache.img |