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Not everyone has a Windows laptop sitting next to the phone. Plenty of people flash ROMs from the phone itself, and for most jobs that is completely fine. What matters is knowing which of the three routes your ROM belongs to, because they are not interchangeable and getting it wrong is how phones end up unusable.

The setup part is short: two APKs, Termux Monet and Termux API, both installed with their permissions granted before you start. Then the flash file from the link. After that everything splits into three paths.

What you need

• Termux Monet and Termux API, installed with permissions granted. Grant them before you start, not when a command fails and you are mid-flash.
• The Termux flash file from the link, placed where Termux can see it.
• The ROM zip for your device, plus the vendor_boot image if your build needs one.
• USB debugging on if you are going to use a PC, or a working terminal setup if you are not.
• A backup. Every one of these routes has a step that erases data somewhere.
• The habit of reading a command before you run it. Some of these are device-specific.

Method 1 - the fastboot ROM

This is the stock-style route. You open the flash tool, choose the fastboot flash option, put the phone in fastboot mode, and let it run. The tool handles the partition writes for you, which is exactly why this is the safest of the three for someone who is new to this.

The catch is what it does to your phone. A fastboot ROM flash writes the full image set, so internal storage comes back empty. That is not a bug in the tool. That is the job. Move your photos off first.

Expect it to take a few minutes and print a long list of partition names while it works. Do not unplug. Do not poke the screen to see if it is alive.

Method 2 - an AOSP ROM through recovery

This route is for clean AOSP builds that come as a flashable zip rather than a fastboot package. Set up the recovery tool first, then flash the recovery and boot images, then send the ROM across.

The order is the part that matters. Recovery and boot images go on before the ROM, because the recovery you already have is usually not the one this build expects. Flashing the ROM first and then trying to fix recovery afterwards is a much harder evening.

Once recovery is in place, the ROM goes across the same way it would from a PC: sideload style, with the phone sitting in recovery and the terminal doing the pushing.

Method 3 - modded ROMs and the vendor_boot step

This is the one to slow down on. Modded ROMs like OxygenOS and DyperOS do not follow either of the first two routes. Here you flash vendor_boot by hand with the fastboot command, then sideload the ROM.

That manual command is where people get hurt. It is short, it looks harmless, and if it was written for a different device you will find out the hard way. Read it. Check that the file name matches the vendor_boot image you downloaded for your exact model. Do not paste a command out of a forum post for another phone.

Then boot recovery, format data, sideload the ROM, and let it boot. If you skipped vendor_boot, recovery will not mount anything and it will look like the zip is corrupt. It is not. You missed a step.

Where people get stuck

• Jumping straight to the ROM. Both the recovery route and the modded route need something flashed before the ROM itself. Skipping it wastes an hour.
• A command written for another device. Fastboot commands that name files and partitions are specific. Copying one from another model's guide is a real way to brick a phone.
• Forgetting the wipe. A fastboot ROM flash erases everything. So does formatting data in recovery. People notice when the photos are gone, not before.
• Permissions not granted. Termux needs its permissions up front. Granting them halfway through a command run is not a good time.

One honest note

Doing this entirely from the phone is convenient, and it works. But a PC is genuinely easier for the recovery and vendor_boot routes, because you can see the output scroll by and you are not fighting a small terminal on a touchscreen. If you have any option at all, and the job is method two or method three, borrow a laptop.

If you do go the PC route, the free Rom Flasher tool on GitHub installs the ADB and fastboot driver for you so you are not stuck with an unrecognised device in Device Manager.

Full description from the video

Three ways to install a ROM on an Android phone - fastboot ROMs, AOSP builds and modded ROMs like OxygenOS or DyperOS - and two of them work without a PC.

Not everyone keeps a Windows laptop next to the phone, and not every ROM flashes the same way. That's the whole point here. The setup is two APKs, Termux Monet and Termux API, both with permissions granted before you start. From there it splits into three routes. Route one handles the stock-style fastboot ROM through the Mi-flash style tool. Route two does AOSP through recovery, where you flash the recovery and boot images first. Route three is the modded ROMs, and that's the one where you flash vendor_boot by hand. Get that command wrong and you'll know about it.

🛠️ What You Need

• Termux Monet and Termux API APKs, permissions granted
• The Termux flash file from the link below
• Your ROM zip, and vendor_boot for AOSP or modded builds
• USB debugging on, or a PC with ADB and fastboot
• A backup, and the habit of reading a command before pasting it

📝 Three Methods

1. Fastboot ROM - open the flash tool, choose the fastboot flash option, put the phone in fastboot, let it run. This wipes the phone.
2. AOSP ROM - set up the recovery tool first, flash the recovery and boot images, then send the ROM across.
3. Modded ROM - flash vendor_boot manually with the fastboot command, then sideload the ROM. OxygenOS, DyperOS and friends go this way.

⚠️ Where People Get Stuck

• Jumping straight to the ROM and skipping the recovery or vendor_boot step.
• Pasting a command written for a different device.
• Forgetting that a fastboot ROM flash erases everything, then wondering where the photos went.

❓ Common Questions

• Do I need a PC? No, Termux covers it. A PC just makes it easier.
• Which method is safest? The fastboot ROM route, because the tool does the work.
• Which one bricks people? Method three. Slow down there.
• Can I use this on any phone? The commands are device-specific.

Common questions

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