Among the images and XML files, you will often see a file named flash_all.bat (or sometimes flash_all_except_storage.bat and flash_all_lock.bat ).
When you download a "Fastboot ROM" for a Xiaomi device (file extension .tgz ), you extract it to find several .bat files: flash all bat xiaomi
For developers or tinkerers, you can modify flash_all.bat to: Among the images and XML files, you will