# Unmount hdiutil detach /Volumes/iPhoneRoot hdiutil create -format UDZO -srcfolder modified_root modified_fs.dmg Rename to Restore.ipsw mv modified_fs.dmg Restore.ipsw Rebuild the IPSW zip zip -r custom_firmware.ipsw *
If you just want to customize iOS, look into or Dopamine / palera1n — they modify the running OS without permanently altering the IPSW. modify ipsw file
Knowledge is neutral. Use these techniques for research, preservation, or education — never for bypassing paid features or distributing malware. Have you successfully modified an IPSW for an older device? Or hit a wall with IMG4 signatures? Drop a comment below! Have you successfully modified an IPSW for an older device
# Check what kind of DMG it is file Restore.ipsw dmg extract Restore.ipsw root_fs.dmg Or use 7zip 7z x Restore.ipsw Mount the DMG (on macOS) hdiutil attach root_fs.dmg On Linux (using dmg2img) dmg2img Restore.ipsw root_fs.img sudo mount -t hfsplus -o loop,ro root_fs.img /mnt/ipsw # Check what kind of DMG it is file Restore
The Deep Dive: How to Modify an IPSW File (And Why You Probably Shouldn’t)
If you modify the IPSW without also exploiting the (A5–A11 chips, iPhone 4s–X), the restore will fail with error 3194 or -1 .
# Rename to .zip mv iPhone3,1_6.1.6_10B500_Restore.ipsw firmware.zip unzip firmware.zip -d ipsw_extracted cd ipsw_extracted Now you’ll see the raw components. The Restore.ipsw file is a compressed DMG (Apple Disk Image).