Flashing a stock ROM using SP Flash Tool is a common method to restore or update the firmware on MediaTek (MTK) based Android devices like Redmi A2. Here’s a step-by-step guide on how to do it:

Note: Flashing firmware can be risky and might lead to data loss or even bricking your device if not done correctly. Make sure to follow the steps carefully and back up your important data before proceeding.

Prerequisites:

1. Make sure your device has sufficient battery life (at least 50%).
2. Download the necessary drivers and tools:
   • SP Flash Tool: Download and install from the official website.
   • Redmi A2 stock firmware: Download the appropriate firmware for your device model.

Flashing Process:

1. Install the MTK USB Drivers:
   • Install the MTK USB drivers on your computer to enable proper communication between your device and the SP Flash Tool.
2. Download and Extract Firmware:
   • Download the correct firmware for your Redmi A2 model from a trusted source.
   • Extract the downloaded firmware package to a folder on your computer.
3. Launch SP Flash Tool:
   • Run the SP Flash Tool application as an administrator.
4. Load Scatter File:
   • In SP Flash Tool, click on the “Scatter-loading” button.
   • Navigate to the firmware folder and select the scatter file (*.txt) associated with your device. This file contains information about the firmware partition layout.
5. Configure Flashing Options:
   • After loading the scatter file, you’ll see a list of partitions to be flashed. Ensure that the necessary partitions (e.g., system, recovery) are selected.
   • Choose the appropriate flashing mode. For a complete firmware installation, select “Download Only” or “Firmware Upgrade” mode. “Format All + Download” should only be used if you’re facing serious issues with your device.
6. Connect Your Device:
   • Power off your Redmi A2.
   • Click the “Download” button in SP Flash Tool.
   • Connect your device to the computer using a USB cable while holding the Volume Down button or any key combination that triggers the device to enter Download or Flashing mode.
7. Flashing Process:
   • SP Flash Tool will start flashing the selected partitions. You’ll see a progress bar indicating the flashing process.
   • Once the flashing is complete, you’ll see a green “Download OK” message.
8. Finish and Reboot:
   • Disconnect your device from the computer.
   • Power on your device. The first boot might take longer than usual as the system is being set up.

That’s it! You’ve successfully flashed the stock firmware using SP Flash Tool. Your Redmi A2 should now be running the official stock ROM.

Remember that these instructions are based on general steps for flashing MTK-based devices. The exact steps might vary slightly based on the specific firmware and version of SP Flash Tool you’re using. So we can’t take responsibility for these instructions. Always refer to the official documentation and resources for your device and tools.