Samsung Galaxy S21, S21+, S21 Ultra & S21 FE Root Guide
Step-by-step Odin rooting tutorial for Galaxy S21 family on Android 14 One UI 6. Covers AP tar patching, custom recovery alternatives, and thermal throttling module optimizations.
Unlocking the bootloader on Samsung devices permanently trips the physical Knox warranty bit (0x1). This permanently disables Samsung Pay, Secure Folder, and Samsung Health hardware keystores. Banking apps and Google Wallet can still be restored using Play Integrity Fix and Shamiko.
Hardware & Partition Specifications
Before flashing, confirm your device matches these exact kernel and partition specifications:
| Hardware Parameter | Target Specification | Engineering Details |
|---|---|---|
| SoC / Chipset | Exynos 2100 / Snapdragon 888 5G |
Hardware processing platform and architecture |
| Target Partition | AP Tar Package (boot.img.lz4) | The exact partition image that must be patched in Magisk |
| OS Compatibility Layer | Android 14 (Upside Down Cake) Layer → | Kernel specifications, SEPolicy patching & 16KB memory page rules |
| RAM Page Alignment | 4KB Page Standard |
Virtual memory kernel standard (Android 15/16 compatibility) |
| Firmware Package | Odin 4-File Firmware |
Official OEM stock ROM packaging format |
| Unlocking Method | OEM Unlocking + Download Mode Long Press Vol Up |
Bootloader unlocking requirement and tool |
| AVB / dm-verity | Requires vbmeta patch | Android Verified Boot verification enforcement |
Step-by-Step Rooting Procedure
Unlock the Samsung Galaxy S21, S21+, S21 Ultra & S21 FE Bootloader
Enable Developer Options by tapping Build Number 7 times in Settings → About Phone. Navigate to Settings → System → Developer Options and toggle on OEM Unlocking and USB Debugging.
OEM Unlocking + Download Mode Long Press Vol Up
Extract the Stock Partition Image
Obtain the official stock firmware archive matching your exact software build number. Extract the required partition image:
Patch Partition in the Magisk App
1. Download and install the latest official Magisk v30.7 APK onto your Samsung Galaxy S21, S21+, S21 Ultra & S21 FE.
2. Transfer the extracted stock AP Tar Package (boot.img.lz4) to your device's Download folder.
3. Open Magisk, tap Install on the top card, and choose Select and Patch a File.
4. Select your file. Magisk will patch the ramdisk and output magisk_patched_[random].img to your Download directory.
5. Transfer the patched image back to your PC via USB.
Flash Patched Image
Connect your device to your computer in bootloader/download mode and execute the verified flashing command:
Emergency Recovery & Bootloop Prevention
If your device fails to boot after installing an incompatible module, use this model-specific hardware recovery procedure:
Recovery Action: Download Mode -> Flash Stock AP
OTA Maintenance: Odin Update with HOME_CSC
Related Guides & Next Steps
Continue setting up your rooted Samsung Galaxy S21, S21+, S21 Ultra & S21 FE with essential modules and protection:
Android 14 (Upside Down Cake) Layer
OS LayerDeep dive into 16KB kernels, init_boot partitioning, and Play Integrity bypass rules.
Samsung Rooting Hub
OEM HubBrowse all supported Samsung smartphones, firmware guides, and OEM tools.
Play Integrity Fix (PIF)
ModulePass MEETS_DEVICE_INTEGRITY attestation and unblock Google Wallet on Samsung Galaxy S21, S21+, S21 Ultra & S21 FE.
Fix Magisk Bootloops
RecoveryEmergency safe mode and ADB module wipe tutorial without data loss.