From the Macintosh ROM of Classic days, to Open Firmware in Power Macs, and on to (U)EFI with Intel, and ending up with LLB and iBoot in Apple silicon Macs.
Open Firmware
All about Mac firmware, from PowerPC Open Firmware to Apple silicon’s LLB and iBoot, and what the rules are for updating firmware.
Since replacing Open Firmware in 2006, EFI firmware has undergone major change. Now only installed as part of a macOS install or update, here’s its story.
The last five years have seen great changes in Mac firmware security. As Intel Macs are replaced by Apple Silicon models, firmware may at last be simpler and more secure at last.
The Eclectic Light Company 