Search results
Results from the WOW.Com Content Network
Those Macintoshes include a ROM chip varying in sizes up to 4 megabytes (MB), [8] which contains both the computer code to boot the computer and to run the Mac OS operating system. The ROM-resident portion of the Mac OS is the Macintosh Toolbox and the boot-ROM part of that ROM was retroactively named Old World ROM upon the release of the New ...
For iPhones, iPads and Apple silicon-based Macs, the boot process starts by running the device's boot ROM. On iPhones and iPads with A9 or earlier A-series processors, the boot ROM loads the Low-Level Bootloader ( LLB ), which is the stage 1 bootloader and loads iBoot; on Macs and devices with A10 or later processors, the boot ROM loads iBoot.
Note: The column MBR (Master Boot Record) refers to whether or not the boot loader can be stored in the first sector of a mass storage device. The column VBR (Volume Boot Record) refers to the ability of the boot loader to be stored in the first sector of any partition on a mass storage device.
Macs made from 1984 to 1998 used Old World ROM as the boot loader for all Macs produced around that time period. From 1998 up until the PowerPC to Intel transition, New World ROM was used for all Macs starting with the first iMac and later expanding to the first iBook and the Blue and White Power Mac G3.
Since the Old World ROM usually boots to Toolbox, most OSs have to be installed using a boot loader from inside Mac OS (BootX is commonly used for Linux installations). 68K-based Macs and NuBus Power Macs must have Mac OS installed to load another OS (even A/UX, which was an Apple product), usually with virtual memory turned off.
A bootloader, also spelled as boot loader [1] [2] or called bootstrap loader, is a computer program that is responsible for booting a computer. If it also provides an interactive menu with multiple boot choices then it's often called a boot manager .
The Toolbox ROM was embedded inside a CHRP script in the System Folder called "Mac OS ROM", along with a short loader stub and a copy of the Happy Mac icon suitable for display from Open Firmware. Once the ROM was loaded from disk, the Mac boot sequence continued as usual.
BootX is a graphical bootloader developed by Benjamin Herrenschmidt, which runs as an application or an extension to Mac OS 8 and 9 that allows Old World Apple computers to dualboot Linux. [ 1 ] [ 2 ]