Always remember: modifying firmware violates Apple's warranty and terms of service. Perform these actions only on devices you own, for educational or research purposes, within legal boundaries.
Encrypted or unencrypted disk images for the system, developer, and recovery partitions. modify ipsw file
Once you've extracted the contents of the IPSW file, you can make changes to it. This can involve modifying files, adding new files, or removing existing files. for educational or research purposes
Modifying a file can sometimes help in preventing the device from automatically updating the baseband, preserving unlock possibilities for older devices. adding new files
On checkm8-compatible devices, you can modify iBEC (the bootloader loaded into RAM) to disable signature checks for subsequent images.