Modify Ipsw File -

# 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 *

# 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). modify ipsw file

If you modify the IPSW without also exploiting the (A5–A11 chips, iPhone 4s–X), the restore will fail with error 3194 or -1 . The Deep Dive: How to Modify an IPSW

The Deep Dive: How to Modify an IPSW File (And Why You Probably Shouldn’t) Or hit a wall with IMG4 signatures

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!