[Redmi Note 9 Questions & Answers] Manjotbenipal:
You can flash your merlin with miflash in fastboot mode irrespective of the chipset.

I have used this method to flash the stock miui rom and I cannot gaurantee succes in case of any third party rom.

I will not be responsible if you brick your device

use at your own risk

Ths guide is for flashing in fastboot without miflash if you are facing some windows problems

YOUR BOOTLOADER MUST BE UNLOCKED

CHECK IT UNDER: SETTINGS>ADDITIONAL SETTINGS>DEVELOPER OPTIONS>MIUNLOCK STATUS

GUIDE

1. Download the fastboot Rom for your device and exract it.

Download it from here:(https://xiaomifirmwareupdater.com/archive/miui/merlin/).

2.Download ADB and Fastboot on your PC Aand install(search about it on google).

3. Download platform tools latest version(download link : https://developer.android.com/studio/releases/platform-tools)(Extract if needed).

4.Now move the extracted files of ROM to platform tools folder.

You should copy or move these files to platform tools folder:

View attachment 5645849

5. Now open flashall.bat with a text editor. It will look like this:View attachment 5645853

6.Erase all the unnecessary content from commands

View attachment 5645855

THESE COMMANDS WILL BE NEEDED WHILE FLASHING IN THE STEPS GIVEN BELOW

WARNING: The content in arrow brackets are an iplaces where you should add the path of file whiie flashing. eg. after writing fastboot flash peloader <you should darg and drop the file here or you can paste the path of preloader file>

(fastboot flash peloader D:\Roms\merlin roms\merlin_in_global_images_V12.0.1.0.QJOINXM_20200731.0000.00_10.0_in\images)

7. Always select the right file as the names of files will be same both in images and flashall.bat file.

8.Now open the platform tools folder and click SHIFT+RIGHTCLICK and select OPEN CMD HERE

or

click on the path of folder and type cmd there and click enter :

View attachment 5645859

9. cmd will open as given:View attachment 5645861

10 . Now connect your phone with pc and type

<adb devices>

you should be able to see your phone serial number and a window will appear on your device

click always alllow and allow your pc to establish a connection with your phone by clicking yes.

11. Again type <adb devices> in cmd and now 'device' should be written besides serial number.

11.TO BOOT INTO FASTBOOT MODE

Type: <adb reboot bootloader> in cmd OR press and hold volume down. + powerbutton simultaneously unti you see a fastboot logo on your device screen.

12. Now type <fastboot devices> and look whether your device is shown or not.

If you cannot see your device serial number with fastboot written besides it then it is a driver issue

WATCH SOME OTHER GUIDES OR VIDEOS REGARDING INSTALLATION OF FASTBOOT DRIVERS OR USB DRIVERS

13. After you see your device in cmd you are ready to flash.

14. ENTER the command one by one which were modified from flashall.bat.

fastboot erase boot
fastboot flash preloader <path of preloader.bin >
fastboot flash logo <path of logo.bin >
fastboot flash tee1 < path of tee.img >
fastboot flash tee2 < path of tee.img >
fastboot flash scp1 < path of scp.img >
fastboot flash scp2 <path of scp.img
fastboot flash sspm_1 < path of sspm.img >
fastboot flash sspm_2 <path of sspm.img >
fastboot flash lk <path of lk.img>
fastboot flash lk2 < path of lk.img>
fastboot flash super< path of super.img>
fastboot flash cache <path of \cache.img>
fastboot flash recovery <path of recovery.img>
fastboot flash boot <path of boot.img>
fastboot flash dtbo <path of dtbo.img >
fastboot flash vbmeta <path of vbmeta.img >
fastboot flash spmfw <path of spmfw.img>
fastboot flash md1img < path of md1img.img >
fastboot flash vbmeta_system < path of vbmeta_system.img>
fastboot flash vbmeta_vendor < path of vbmeta_vendor.img>
fastboot flash cust < path of cust.img>
fastboot flash exaid < path of exaid.img>
fastboot flash userdata < path of userdata.img>
fastboot reboot

Take care of the spaces you should leave only one space between individual words of above commands

Now your device is flashed and it will automatically reboot into new STOCK ROM