ROM for Samsung galaxy a5 2017 (SM-A520F)

The Samsung Galaxy A5 2017 (SM-A520F) remains a highly sought-after device in the refurbished and budget smartphone market, valued for its premium glass design, water resistance, and capable Exynos 7880 processor. However, after years of official support cessation, the device requires Custom ROMs to unlock its full potential, extend battery life, and run the latest versions of Android. At Magisk Modules, we specialize in providing the ecosystem necessary to enhance these custom ROM installations, ensuring stability and performance through our curated Magisk Module Repository.

Navigating the landscape of Android development for legacy Samsung devices requires precision. The Exynos 7880 architecture, while robust, presents specific challenges regarding kernel compatibility, vendor partition configurations, and SELinux policies. This comprehensive guide details the optimal Custom ROMs available for the SM-A520F, addresses common installation hurdles—such as the notorious internal storage writing issues—and integrates the essential Magisk modules required to transform this 2017 hardware into a modern daily driver.

Understanding the Samsung Galaxy A5 2017 Architecture

Before flashing any firmware, it is imperative to understand the hardware architecture of the SM-A520F. Unlike many Qualcomm-based Samsung devices, the A5 2017 runs on the Exynos 7880 Octa chipset. This System on Chip (SoC) utilizes ARM Cortex-A53 cores and the Mali-T830 MP3 GPU.

Partition Layout and A/B Seamless Updates

The SM-A520F utilizes a legacy partition layout rather than the A/B seamless update system found in modern Android devices. This means system updates require overwriting the active system partition directly, necessitating a full reflash of the ROM upon major version updates. The critical partitions for Custom ROM installation include:

• boot: Contains the kernel and initial ramdisk.
• system: Hosts the Android OS framework.
• recovery: Stores the custom recovery environment (TWRP).
• cache: Temporary storage for OTA updates (less critical for custom ROMs).
• userdata: User storage space.

Samsung’s Security Architecture (FRP and Knox)

The SM-A520F features Samsung’s Knox security platform. Flashing Custom ROMs trips the Knox warranty void bit (Knox 0x1), permanently disabling Samsung Pay and Secure Folder. Additionally, the Factory Reset Protection (FRP) lock must be bypassed correctly during the initial setup. We recommend utilizing ADB commands to disable FRP triggers during the post-installation phase to prevent boot loops into the setup wizard.

Top Custom ROMs for SM-A520F

The development community for the A5 2017 has matured, offering stable Android 10 and Android 11 builds. While Android 12 and 13 exist, they often suffer from stability issues regarding the legacy Mali drivers and proprietary Samsung camera HALs.

LineageOS 18.1 (Android 11)

LineageOS remains the gold standard for stability on the SM-A520F. Built from the ground up, it offers a near-stock Android experience with essential tweaks.

• Performance: The ROM is highly optimized for the Exynos 7880, maintaining smooth 60fps transitions.
• Battery Life: Includes custom kernel governors that manage the 1.7 GHz octa-core frequency scaling efficiently.
• Compatibility: Native support for microG makes it ideal for privacy-conscious users.

crDroid 6 and 7 (Android 10 and 11)

crDroid is a feature-rich ROM based on LineageOS, offering extensive customization options via the crDroid Settings app. However, specific versions have known bugs.

• crDroid 6.20 (Android 10): This is the most stable iteration for the A5 2017. It features active development and reliable daily performance. A known issue, however, involves write permissions to internal storage.
• crDroid 7 (Android 11): While offering a newer Android base, early builds suffered from bootloops on the A520F. Community reports suggest that crDroid 7 works successfully only if crDroid 6.20 is installed as a base firmware first, bridging the partition gaps.

Pixel Experience (Android 10)

For users desiring the Google Pixel aesthetic, Pixel Experience offers a clean interface with Google Apps (GApps) pre-integrated. This ROM sacrifices some customization for a fluid, bloat-free experience. It is generally stable but may lack specific hardware toggles (like LED notification light control) compared to LineageOS.

Addressing the crDroid Storage Bug: A Technical Guide

One of the most pervasive issues for SM-A520F users is the inability to write to internal storage on certain custom ROMs, particularly crDroid 6.20. This issue stems from f2fs (Flash-Friendly File System) versus ext4 formatting conflicts on the /data partition.

The Problem: Read-Only Internal Storage

When flashing crDroid 6.20 on a fresh install, users often encounter a “Storage Space Running Out” error, even with ample free space. This occurs because the ROM attempts to write cache and app data to a partition mounted as read-only by the recovery or kernel. The Reddit discussion highlighted confirms that without a specific base firmware, the SELinux contexts are mislabeled, preventing media and android users from writing to /data.

The Solution: The Two-Step Flash Method

Based on community validation, the workaround for crDroid 7 installation—resolving the bootloop and storage issues—involves a sequential flashing process:

1. Wipe Partitions: In TWRP, perform a Factory Reset (Wipe Data, Cache, and Dalvik). Ensure the internal storage is formatted as F2FS if supported, though ext4 is safer for compatibility.
2. Step 1 - Install crDroid 6.20: Flash the crDroid 6.20 zip file first. This populates the vendor partition with the correct file system drivers and permission maps for the Exynos 7880.
3. Step 2 - Install crDroid 7: Without rebooting into the OS (or booting once to verify storage), immediately flash the crDroid 7 zip file over the 6.20 installation.
4. Format Data: After flashing both, go to Wipe > Format Data and type ‘yes’. This ensures the encryption footer is cleared and the file system is properly initialized for the Android 11 environment.

Prerequisites for Installation

To ensure a seamless transition to a Custom ROM on the Samsung Galaxy A5 2017, the following prerequisites are mandatory.

Recovery Environment

The standard Android recovery is insufficient. You must install a custom recovery capable of handling Samsung’sOdin flashing format.

• Recommended: TWRP (Team Win Recovery Project) or OrangeFox Recovery.
• Installation: These are typically flashed via the Odin tool on Windows or Heimdall on Linux, utilizing the AP slot.
• Note: Always ensure you have the specific recovery.img for the SM-A520F. Using an image for the SM-A520FD (dual SIM) or SM-A520K (Korean variant) can result in a hard brick.

Samsung USB Drivers and Odin

A Windows PC is recommended for the initial recovery installation. Samsung USB drivers must be installed to allow Odin to recognize the device in Download Mode.

• Odin3 v3.13.1 or newer is required to flash the TWRP tar file.
• Heimdall is the preferred cross-platform alternative for Linux users, utilizing heimdall flash.

Battery and Backup

• Charge Level: Ensure the device battery is above 60%. A sudden shutdown during the partition flashing process can corrupt the EMMC, permanently bricking the device.
• NANDroid Backup: Once TWRP is installed, create a full backup of the stock ROM (System, Data, Boot, EFS) to an external SD card. The EFS partition contains IMEI data; losing it will render the device unable to connect to cellular networks.

The Role of Magisk in Custom ROMs

Once the Custom ROM is booting successfully, the installation of Magisk is the next critical step. As the developers of Magisk Modules, we emphasize that Magisk is not merely for root access but is the gateway to systemless modifications.

Why Systemless Root?

Traditional rooting methods (like Chainfire’s SuperSU) modify the /system partition directly, triggering SafetyNet and breaking banking apps. Magisk mounts root overlays in a virtualized partition, keeping the original system files intact.

Essential Modules from the Magisk Module Repository

To optimize the A5 2017 on Custom ROMs, we recommend specific modules available at https://magiskmodule.gitlab.io/magisk-modules-repo/:

1. Exynos 7880 Thermal Throttling Fix: The A5 2017 tends to throttle aggressively under load. A custom thermal configuration module can unlock sustained performance for gaming without overheating (capped at 85°C).
2. GSIs and Vendor Display Interfaces: If utilizing a GSI (Generic System Image), a vendor display interface module is often required to fix camera and display scaling issues on the 1080p Super AMOLED panel.
3. Audio Modification Libraries: Samsung’s stock audio drivers are excellent. A module to port the stock Samsung SoundAlive engine to AOSP ROMs ensures the headphone audio quality matches the stock experience.
4. SQLite Database Optimization: Custom ROMs often leave background job logging enabled. An optimization module can defragment the app databases, reducing battery drain from android.process.media.

Step-by-Step Installation Procedure

Follow this procedure to install a stable Custom ROM on the Samsung Galaxy A5 2017.

Phase 1: Flashing TWRP

1. Download the twrp-3.x.x-a520f.tar file.
2. Power off the device. Boot into Download Mode by holding Volume Down + Home + Power.
3. Open Odin on your PC. Uncheck Auto Reboot.
4. Load the TWRP tar file into the AP slot.
5. Click Start. Once passed, immediately hold Volume Up + Home + Power to boot into TWRP (preventing the stock recovery from overwriting TWRP).

Phase 2: Wiping and Formatting

1. In TWRP, go to Wipe > Advanced Wipe.
2. Select Dalvik / ART Cache, System, Data, and Cache. Swipe to Wipe.
3. Crucial Step: Go to Wipe > Format Data. Type ‘yes’. This wipes the data partition and removes encryption, which is the primary cause of boot loops in custom ROMs.

Phase 3: ROM Installation

1. Download the Custom ROM zip (e.g., LineageOS 18.1 or crDroid).
2. Transfer the zip to the device via MTP or ADB sideload (adb push rom.zip /sdcard/).
3. Go to Install in TWRP. Navigate to the ROM zip.
4. Swipe to flash.
5. (Optional) If the ROM does not include GApps, flash the arm64 compatible package immediately after the ROM (e.g., OpenGApps or MindTheGApps). Do not flash GApps before the ROM or on top of a GApps-included ROM.
6. Wipe Cache/Dalvik and reboot.

Post-Installation Configuration

After the device boots, you will enter the Android Setup Wizard. Upon reaching the home screen, the system will be relatively bare. This is where the Magisk Modules ecosystem becomes vital.

Verifying Root Access

1. Open the Magisk app.
2. Check the installed version. If a “Direct Install” update is available, perform it to ensure the init_boot patch is stable.
3. Browse our repository (https://magiskmodule.gitlab.io/magisk-modules-repo/) for modules that complement the specific ROM chosen.

Fixing Common Legacy Issues

• Camera Quality: AOSP ROMs often suffer from reduced camera quality compared to stock Samsung One UI. We recommend using a Camera2 API Enabler module to force the use of the Google Camera (GCam) port, which significantly improves dynamic range and low-light performance on the Exynos 7880.
• Battery Drain: If you notice excessive drain in the first 24 hours (due to indexing), install a Doze GMS Config module to optimize Google Play Services’ background activity.

Troubleshooting Common Errors

Boot Loop After Flashing

If the device gets stuck in a boot loop (Samsung logo infinite loop):

• Cause: File system corruption or incorrect GApps.
• Solution: Boot into TWRP. Wipe Cache and Dalvik. If that fails, Format Data again and reflash the ROM. Ensure the ROM zip is not corrupted (verify MD5).

“Error 255” in TWRP

This error occurs when TWRP cannot mount the system or data partition.

• Cause: Encryption is still active on the data partition.
• Solution: Go to Wipe > Format Data. This is mandatory for most AOSP ROMs on Samsung devices.

Internal Storage Not Mounting (The crDroid Issue)

As mentioned in the user report, if internal storage is read-only:

• Cause: Missing vold configurations or SELinux denials.
• Solution: This is often fixed by the two-step flashing method (6.20 -> 7). If not, flash a SELinux Mode Changer module from the Magisk repository and set it to Permissive temporarily (though Enforcing is recommended for security).

Long-Term Maintenance and Updates

Maintaining a Custom ROM on the Samsung Galaxy A5 2017 requires a disciplined approach.

OTA Updates

Most Custom ROMs like LineageOS and crDroid support OTA updates via an in-app updater.

• Never install an OTA update directly through the updater app without TWRP installed.
• Process: Download the update via the app, reboot to recovery, flash the update zip, flash GApps (if needed), and flash the Magisk zip (if the update overwrites the boot partition).

Module Management

Keep your Magisk Modules lean. Installing too many modules can cause system instability or the dreaded “Boot Loop of Death.”

• Periodically check the Magisk Module Repository for updates.
• Remove unused modules via the Magisk app to ensure the system boots quickly and runs efficiently.

Why Choose Magisk Modules?

While there are many sources for rooting tools, Magisk Modules (https://magiskmodule.gitlab.io) offers a curated selection of modules specifically tested for stability on legacy devices like the Galaxy A5 2017. Our repository focuses on:

• Performance Enhancements: Kernel tweaking and CPU governors.
• Visual Customization: System UI themes that are lightweight and battery-efficient.
• Functionality: Restoring features removed by Custom ROMs (e.g., Samsung Health or Secure Wi-Fi wrappers).

By combining a stable Custom ROM like crDroid 6.20 or LineageOS 18.1 with the optimized modules from our repository, the Samsung Galaxy A5 2017 can perform at a level surpassing its original factory state.

Conclusion

The Samsung Galaxy A5 2017 (SM-A520F) is a capable device that deserves a second life through Custom ROMs. While the path to Android 11 involves navigating technical hurdles—such as the specific installation order for crDroid versions and file system formatting protocols—the result is a secure, fast, and modern Android experience.

We at Magisk Modules are committed to supporting this legacy hardware. By following the detailed procedures outlined above and utilizing our repository, users can bypass the obsolescence imposed by the manufacturer and enjoy a fully customized, root-accessible smartphone. Always remember to verify your device model, backup your data, and prioritize stability over experimental builds to ensure the longevity of your device.