Searching online yields dozens of "MStar firmware tools." Most are broken, abandoned, or simply wrappers around dd. The Exclusive variant we are discussing refers to a closed-source or highly specialized script family (often leaked from official service centers or developed by Chinese reverse engineers like Hako, MSToolKit, or FirmwareModKit).
Once you have the boot.img or system.img:
The dump mstar unpack repack tool exclusive exists in a gray area. dump mstar unpack repack tool exclusive
Manufacturer Warning: Using this tool voids warranties. Modified firmware can permanently disable your device if the bootloader hash chain fails.
Always keep a backup of your original dump on two separate drives. If your repack fails, you can always flash back the exact original. Searching online yields dozens of "MStar firmware tools
Due to the exclusive nature, you cannot find it on GitHub. Try these avenues (with extreme caution):
Danger Zone: Many EXE files claiming to be the exclusive tool contain ransomware or miners. Run them inside a Windows Sandbox or a disposable VM with no internet access. Manufacturer Warning: Using this tool voids warranties
Better yet, look for Python-based open-source alternatives (like mstar-unpack.py on GitLab) and modify them to add the exclusive features yourself.