Patch-based method; considered harder for Apple to patch server-side. iOS 15.0 - 18.1.1 UnlockTool
Creating a functional ramdisk for the iPhone XR involves several high-level steps. Unlike the iPhone 7 or 8, you cannot simply use ipwnder or checkra1n due to the lack of a BootROM exploit. Instead, modern methods rely on (a bootloader replacement) or Blackbird exploits (for iOS 13–15). iphone xr ramdisk
Use a toolkit like or sshtar to generate a ramdisk.dmg and devicetree.img4 for the XR ( iPhone11,8 ). Example (with sshtar): Patch-based method; considered harder for Apple to patch
Sending ramdisk... Patching ASLR... Mounting filesystem... iphone xr ramdisk