The Samsung Galaxy A20s (SM-A207F, SM-A207G, SM-A207M) is a dependable budget smartphone that serves millions of users. However, as time passes, the stock Samsung firmware often begins to feel sluggish: games lag, apps take longer to open, and the device heats up more than it should. If your Galaxy A20s has started showing its age, there's a fantastic solution: Nusantara OS.
Nusantara OS is a specially crafted GSI (Generic System Image) custom ROM designed to be exceptionally lightweight, gaming-optimized, and perfectly stable for daily use. It combines performance tweaks for smoother gaming with the reliability you need for everyday tasks calls, messaging, social media, and everything in between. Think of it as the best of both worlds: a fast, responsive experience whether you're gaming or just browsing.
This guide will walk you through installing Nusantara OS onto your Samsung Galaxy A20s. You can install it directly from your phone's internal storage, via an SD card, or by connecting to a computer whichever works best for your situation. By the end, your A20s will feel faster, run games more smoothly, and stay cool all while maintaining rock-solid stability.
⚠️ Important Warnings Before You Begin
Before we proceed, please understand what you're doing and the risks involved:
- All Data Will Be Erased: Installing a custom ROM requires formatting your data partition. Back up everything important photos, videos, contacts, app data to Google Drive, an SD card, or another device before starting.
- Warranty May Be Voided: Unlocking the bootloader and installing custom software will trip Samsung's Knox security counter, which may void your official warranty. Samsung Pay, Secure Folder, and some banking apps may stop working.
- Potential Bootloop: If you skip critical steps like formatting data or flash incompatible files, your device may become stuck in a boot loop. Follow every step carefully.
- Compatibility: This guide is specifically for the Samsung Galaxy A20s (SM-A207F, SM-A207G, SM-A207M). Do NOT attempt this on other Samsung models.
- Community GSI Build: Nusantara OS for the A20s is a community-built Generic System Image. While thoroughly tested and stable, minor edge-case features may differ from official device-specific ROMs.
✅ Prerequisites
Ensure you have all of the following before starting:
- Samsung Galaxy A20s (SM-A207F / SM-A207G / SM-A207M) with unlocked bootloader and TWRP recovery installed
- Battery charge of at least 70%
- Internet connection to download the required files
- At least 4-5 GB of free storage space internal storage, SD card, or computer works
- Complete backup of all personal data
- If you haven't yet unlocked your bootloader or installed TWRP, you must do those first; they are mandatory prerequisites.
📥 Files You Need to Download
There are two essential files you'll need. Save them to a location you can access:
| File | Purpose |
|---|---|
| Nusantara OS ROM | The main operating system file — extract it to get the .img file |
| Permissive Boot Image | Required kernel to boot the GSI properly and prevent boot loops |
Note: If the Nusantara OS file downloads in a compressed format (
.zipor.xz), extract it first until you get the.imgsystem image file. That is the file we will flash.
Where to save the files:
- Option A (Best): Copy directly to your phone's internal storage if TWRP can read it; installation is fastest.
- Option B: Save to an SD card the most reliable option if internal storage appears encrypted.
- Option C: Save to a computer first, then transfer to your phone once inside TWRP via USB.
🔑 Prerequisite: TWRP Recovery Must Be Installed
Before you can flash anything, your Galaxy A20s must already have TWRP custom recovery installed. If you haven't installed TWRP yet, you cannot proceed with this guide. You'll need to:
- Unlock your device's bootloader first
- Flash TWRP recovery
- Verify that you can successfully boot into TWRP
Once TWRP is installed and working, return here and continue with the ROM installation steps below.
📲 Step-by-Step: Install Nusantara OS
Step 1: Boot into TWRP Recovery
- Power off your Samsung Galaxy A20s completely; wait until the screen goes black and the device stops vibrating.
- Press and hold the Volume Up button + Power button simultaneously.
- When the Samsung Galaxy A20s logo appears, release ONLY the Power button while continuing to hold the Volume Up button.
- Keep holding Volume Up; the screen may go black for a moment, then TWRP will load.
Step 2: Check Storage Access & Transfer Files
Once inside TWRP, check if your internal storage is readable:
✅ If Internal Storage Is Readable:
- Great! Simply copy the extracted Nusantara OS
.imgfile and the Permissive Boot Image to your phone's internal storage. You can do this before booting into TWRP or by connecting to a computer via USB once inside TWRP. Proceed to Step 3.
❌ If Internal Storage Shows Encrypted/Random Folder Names:
- TWRP cannot read encrypted storage yet. Do this first:
- Go to Wipe → Format Data
- Type "yes" and confirm
- Reboot back into TWRP (Reboot → Recovery)
- Now internal storage will be readable
- Connect to your computer and copy both files over
- ⚠️ Important: Formatting data erases everything, so copy your files after formatting, not before. If you have an SD card, you can save the files there beforehand and avoid this complication.
Step 3: Flash the Nusantara OS System Image
- From the TWRP main menu, tap Install.
- Tap the "Install Image" button (not the regular ZIP Install button).
- Navigate to where you saved the Nusantara OS
.imgfile. - Select the file.
- When asked which partition to flash, select System Image.
- Swipe the slider at the bottom to confirm and begin flashing.
- Be patient; flashing the system image takes several minutes. Let it finish completely.
- When done, you'll see a "Successful" message.
Step 4: Flash the Permissive Boot Image
- Tap Back to return to the file selection screen.
- Tap "Install Image" again.
- Select the Permissive Boot Image file.
- When asked which partition to flash to, select Boot Image.
- Swipe to confirm and flash the boot image.
- Wait for the "Successful" confirmation.
⚠️ DO NOT SKIP THIS STEP! The Permissive Boot Image is absolutely required. Without it, your phone will almost certainly be stuck in an infinite boot loop restarting over and over without ever reaching the home screen.
Step 5: Format Data Partition (CRITICAL: Do NOT Skip)
- Return to the TWRP main menu and tap Wipe.
- Tap Format Data (NOT "Advanced Wipe").
- Type "yes" using the on-screen keyboard and confirm.
- Wait for formatting to complete.
⚠️ Even if you already formatted data earlier to make storage readable, do it again here before rebooting. This ensures the data partition is perfectly prepared for the new ROM.
Step 6: Reboot into System
- Tap Reboot → System.
- Be extremely patient. The first boot after installing a custom ROM takes much longer than usual, anywhere from 5 to 15 minutes- and is completely normal. You may see the Samsung logo for an extended time. Do NOT manually restart it.
✅ Success! Set Up Nusantara OS
Once your Galaxy A20s finally boots up:
- You'll be greeted by the Nusantara OS setup wizard.
- To speed things up, you can temporarily enable Airplane Mode during setup to skip the Wi-Fi sign-in screen quickly.
- Once you reach the home screen, reconnect to Wi-Fi, sign in with your Google account, and restore your apps.
- Verify everything works: IMEI intact, display brightness adjustable, fingerprint sensor responsive, camera functioning.
Nusantara OS is designed to be gaming-optimized AND daily-stable. You'll notice smoother animations, quicker app launches, cooler temperatures during use, and significantly reduced lag in games all while keeping every essential feature working reliably.
🎮 Why Nusantara OS? Gaming Performance + Daily Stability
Nusantara OS stands apart from other custom ROMs because it's built with a clear philosophy: great for gaming, perfect for daily use.
| Feature | Benefit |
|---|---|
| Ultra-Lightweight | Minimal bloatware, more free RAM, faster everything |
| Anti-Lag Optimizations | Tweaked CPU/GPU scheduling = smoother gaming |
| Thermal Improvements | Runs cooler, less throttling during long gaming sessions |
| Stable Daily Use | Calls, SMS, Wi-Fi, camera, fingerprint — all rock-solid |
| Clean & Polished | Thoughtful design, no unnecessary clutter |
Every essential function mobile network, Wi-Fi hotspot, IMEI, camera, fingerprint sensor remains fully functional and secure. While any custom ROM may have minor edge-case quirks, Nusantara OS has been tested and proven reliable for daily use, gaming, and everything in between.
⚠️ Troubleshooting Common Issues
Stuck in Boot Loop / Restarting Continuously
- Cause: You skipped the Permissive Boot Image step or didn't format data.
- Fix: Reboot into TWRP → Flash Permissive Boot Image → Wipe → Format Data → type "yes" → Reboot.
TWRP Shows Random/Encrypted Folder Names
- Cause: Internal storage is encrypted.
- Fix: Wipe → Format Data → type "yes" → Reboot to TWRP. Storage will now be accessible. Copy your files and proceed.
First Boot Takes a Long Time
- Normal! Custom ROMs take longer to optimize apps and services on first boot. Wait at least 15 minutes before assuming it's stuck.
📌 Quick Recap of Critical Steps
To avoid issues, remember this order:
- ✅ Have TWRP installed and working
- ✅ Download Nusantara OS + Permissive Boot Image
- ✅ Flash Nusantara OS as System Image
- ✅ Flash Permissive Boot Image as Boot Image
- ✅ Format Data (type "yes")
- ✅ Reboot → System → Be patient
Conclusion
Nusantara OS is one of the most exciting custom ROMs available for the Samsung Galaxy A20s, lightweight enough to feel snappy, optimized enough to run games smoothly, and stable enough to trust with your daily communications. By following this guide preparing your files, flashing the system image, flashing the Permissive Boot Image, formatting data, and rebooting you can breathe new life into your A20s without needing advanced technical knowledge.
The Permissive Boot Image and Format Data steps are not suggestions; they are mandatory safeguards against boot loops. Follow them exactly, be patient during that first boot, and you'll be rewarded with a faster, cooler, smoother Galaxy A20s.
Enjoy your new Nusantara OS experience! 🎮✨
