If you come across terms like “bootloader unlock” or “OEM unlock” when looking to customize your Samsung Galaxy S20 but don’t know what is it, then you are in the right place.

Unlocking the bootloader is a step for users who want to install custom ROMs, recoveries, or obtain root access to their devices. In this guide, we’ll cover everything you need to know about the bootloader on your Samsung Galaxy S20, why you might need to unlock it, and the steps to do so. Let’s get started!

Note: Solutions in this guide will work on any Samsung Galaxy S20 model (S20, S20 Plus, S20 Fe, and S20 Ultra models.)

Editor’s note: We created these instructions using a Samsung Galaxy S20 running Android 13. Depending on your device’s software version, some steps and menu positions may look slightly different.

What is a Bootloader?

Have you ever thought about what happens when you power on your Samsung Galaxy S20? The bootloader is a component that kicks off this process. But what exactly is a bootloader?

In general, a bootloader is a piece of low-level software that initializes the hardware of your device and loads the operating system (OS). It’s the first piece of code that runs when you turn on your device. You can think of it as the gatekeeper that makes sure the right OS is loaded securely.

If you want a technical explanation, it is like the BIOS on a computer. The bootloader exists in a reserved partition of the device’s non-volatile memory called the “NAND” flash memory and operates at a level above the device’s firmware but below the operating system. Its responsibilities include:

• Initializing hardware components: The Bootloader ensures that all the necessary parts of your phone are in a ready state to function correctly.
• Verifying digital signatures: It checks the integrity of the OS and other software components to ensure they haven’t been altered, which is a critical security measure.
• Loading the OS into memory: Once it verifies the software, it loads the OS kernel into RAM to set the stage for the device to boot up completely.

The bootloader in the Samsung Galaxy S20 works similarly to other Android smartphones. However, unlike other Android devices, the Galaxy S20’s bootloader contains an additional layer of security called Samsung’s Knox security platform.

How to Unlock the Bootloader in Samsung Galaxy S20

Unlocking the bootloader is a process that allows you to gain deeper access to the phone’s operating system. This is a necessary step if you plan to install custom ROMs, recoveries, or perform other advanced software modifications.

Note: Please read the warranty section before unlocking the bootloader. This process will wipe all data on your device, so ensure you have backed up any important information.

Here are the steps to unlock the bootloader on your Samsung Galaxy S20:

Enable Developer Options:

1. Go to Settings. Scroll down and tap on “About phone”.

2. Tap on “Software information”.

3. Find the “Build number” and tap on it 7 times until you see a message that says “Developer mode has been enabled”.

Enable OEM Unlocking:

1. Return to the main Settings menu.
2. Scroll down and tap on “Developer options” which should now be visible.

3. Scroll down and toggle on the “OEM unlocking” option.

Enter Download Mode:

1. Power off your Galaxy S20.
2. Press and hold the Volume Up and Volume Down buttons simultaneously.
3. While holding these buttons, connect your phone to a computer using a USB cable.
4. Continue holding the buttons until you see a warning screen.

Unlock the Bootloader:

1. Once in Download Mode, long press the Volume Up button to unlock the bootloader.
2. Press the volume up button again to confirm unlocking the bootloader.

Your phone will display a message confirming that the bootloader is unlocked. The device will automatically reboot, and on startup, it will perform a factory reset. After these steps, your Samsung Galaxy S20 will have an unlocked bootloader. 

FAQ

Does Samsung Allow Bootloader Unlock?

While Samsung does not explicitly prevent users from unlocking the bootloader on their devices, the company does not actively encourage it either. The reason behind this approach is tied to security and user experience.

Unlocking the bootloader on a Samsung Galaxy S20, or any Samsung device for that matter, can pose potential security risks. This is because the bootloader serves as a security checkpoint that ensures only trusted software runs on the device. By unlocking it, you are lowering the phone’s defenses against malicious software.

Furthermore, Samsung Knox, their security platform includes a set of security checks to safeguard user data. Unlocking the bootloader can trip the Knox warranty, which indicates that non-Knox-approved software has been loaded onto the device. This can lead to the loss of security features and services provided by Knox.

Does unlocking the bootloader void warranty?

It is important to understand unlocking the bootloader on your Samsung Galaxy S20 may avoid your device’s warranty. Unlocking the bootloader itself does not directly void the warranty; however, it’s the actions that typically follow the unlocking process that can affect warranty status.

This means, that if you decide to install custom firmware, root the device, or make other system-level changes after unlocking the bootloader, these modifications will void the warranty.

Does Unlocking Bootloader Delete Everything?

Yes. When you unlock the bootloader on your Samsung Galaxy S20, it will indeed erase all the data on your device.

Is the bootloader a firmware?

No. The bootloader is not firmware itself, but rather a piece of code that is crucial for the device’s firmware.

Is the bootloader the same as the download mode?

No, the bootloader and download mode are not the same things. Each serves a distinct purpose within the device’s ecosystem.

Download mode is a state that Samsung devices can enter, which allows for system-level modifications or installations. It is also known as Odin mode, named after the Odin tool used to flash firmware on Samsung devices.

Is the bootloader and fastboot the same?

No, the bootloader and fastboot are not the same things. The bootloader is a specific code that is stored on the device’s memory and is executed at startup, fastboot is a protocol that allows you to communicate with the bootloader for development and troubleshooting purposes.