🇧🇷 Portuguese

The Oilsky M308 is a portable digital audio player (DAP) running Android 9.0, focused on high fidelity audio but fully capable of being optimized into a dedicated, lightweight, streamlined player.

Warning: These operations may brick your device. I take no responsibility for any damage.

• boot_imgs/boot.img — Example of original boot image backup

• boot_imgs/magisk_patched-29000_K4B4T.img — Ready-to-flash Magisk-patched boot image

• data/adb/services.d/ — Optimization/automation shell scripts

  • 99-google.sh
  • 99-powersave.sh
  • 99-reduce-priority.sh
  • 99-services.sh

• debloat.sh — Aggressive bloatware removal script

• dont-disable.txt — List of packages you must not disable (to avoid bootloop)

• img/oilsky_mkt.jpg — Oilsky product photo

• magisk_modules/Hi-Res-Audio-Enabler-MagiskModule.zip — Magisk Hi-Res Audio Module

1. Prerequisites
2. Backing Up boot.img with mtkclient
3. Patching boot.img with Magisk
4. Using the Ready Magisk Boot Image (Optional)
5. Flashing the Patched boot.img with fastboot
6. System Optimization (RAM/CPU)
7. Magisk Modules & Hi-Res Audio
8. System Debloat & Battery Saving
9. Restoring the Original boot.img
10. References

• Python installed
• mtkclient (link)
• ADB and Fastboot installed
• Magisk APK (official link)
• Compatible Oilsky M308 firmware
• Unlocked bootloader (fastboot oem unlock)
• USB debugging enabled

Power off the device, unplug USB, and prepare for BROM mode.

On your PC, run:

python mtkclient.py r boot boot.img
# mtkclient will wait for device connection.

Connect the device without pressing any buttons. mtkclient will back up the boot partition as boot.img. Keep this file safe!

1. Transfer the boot.img to your device (USB, adb push, or SD card).
2. Install and open the Magisk app.
3. Tap Install > Uncheck recovery mode > Next > Method > Select and Patch a File > choose your boot.img.
4. Magisk will generate magisk_patched-XXXXX.img.
5. Copy this file back to your PC.

If you want to use a pre-patched boot image, one is available at:

• boot_imgs/magisk_patched-29000_K4B4T.img

WARNING: Always back up your original boot image before flashing any new image! Using an image from another firmware or device may cause irreparable brick.

On your PC:

adb reboot bootloader
fastboot flash boot magisk_patched-XXXXX.img
fastboot reboot

For an even lighter system, try:

• Launcher: Pie Launcher (super lightweight)
• Music Player: Poweramp (lets you force Hi-Res output and view audio processing details)

Additional scripts can be found in data/adb/services.d/ (see: 99-powersave.sh, 99-reduce-priority.sh).

• BuiltIn-BusyBox (Magisk)
• Hi-Res-Audio-Enabler (customized, available at magisk_modules/Hi-Res-Audio-Enabler-MagiskModule.zip): Based on reiryuki/Hi-Res-Audio-Enabler-Magisk-Module, forces 32-bit / 192 kHz headphone output (even though the device specs list only 16-bit support).

Special thanks to reiryuki for the original scripts.

Note: The debloat.sh script is extremely aggressive and is designed to turn the device into a simple, dedicated player! Install your launcher and other apps first, or adjust the scripts as needed.

• After rooting, run debloat.sh and reboot.
• Never disable packages listed in dont-disable.txt — doing so can cause bootloop.

As root, copy the scripts from data/adb/services.d to the same location on your device. These scripts, run on every boot, will disable Google services, force airplane mode, reduce process priority, and disable various background services. Feel free to edit them to your needs.

To restore your original boot:

fastboot flash boot boot.img

Always keep a backup of your original boot.img to avoid bricks.

• mtkclient
• Magisk (topjohnwu)
• ADB/Fastboot
• Pie Launcher (F-Droid)
• Poweramp
• Hi-Res Audio Enabler (reiryuki)
• BuiltIn-BusyBox Magisk Module