Kick start

Kickstart

The Kickstart is the part of the AmigaOS operating system that resides in ROM. It could be the equivalent of PC BIOSes, although it really goes much further than just being a motherboard configuration manager.

The Kickstart contains:

• A boot manager (Early Startup);
• The core of the AmigaOS;
• The most important libraries
• The fundamental part of the graphic environment.

Together with the Workbench they make up the operating system of the AmigaOS. However, only with the Kickstart code is it possible to boot the Amiga directly with the windowing environment and a CLI (Command Line Interface).

Contains the code necessary to boot the standard Amiga hardware and many of the core components of the AmigaOS. The function of the Kickstart is comparable to that of the BIOS plus the operating system kernel on an IBM PC compatible computer. Even so, Kickstart has more features available at boot than initially expected on a PC, eg the full window system.

The Kickstart contains many basic parts of the Amiga operating system, such as Exec, Intuition, the AmigaDOS kernel, and functionality for using plugins hardware via Autoconfig. This means that a newly powered up Amiga has many of the essential parts of an operating system available. Later versions of the Kickstart contained drivers for IDE and SCSI controllers, PC Card ports, and other hardware built into the Amiga.

On (re)boot, the Kickstart performs a number of system checks and diagnostics and then boots the Amiga chipset and some OS kernel components. It then examines the attached boot devices and tries to boot from one of the higher boot priority ones. If no bootable device is found, a screen is displayed asking the user to insert a bootable disk, typically a floppy disk.

The first Amiga model, the 1000, requires the Kickstart 1.x to be loaded from a floppy disk into a 256 KB section of RAM, called the writable control store(WCS). Some A1000 programs (mainly Dragon's Lair) included an alternative codebase to be able to use those extra 256KB for data. Later Amiga models include the Kickstart on a ROM chip, thus improving boot times. The A1000 can also be modified to include such chips.

The Kickstart was stored on 256 KB ROM chips in versions prior to AmigaOS 2.0. Later versions use 512 KB ROM chips, containing new and improved functionality. The Commodore Amiga CD32 includes a 1 MB ROM (Kickstart 3.1) with additional firmware and an integrated file system to support CD-ROM drives.

Early Amiga 3000 models were, like the A1000, packaged with the Kickstart on a floppy disk, because they included version 1.4 beta ROM. Both the 1.3 and 2.0 kickstarts could be extracted to a partition specifically named WB_1.3 or WB_2.x, respectively, and included in DEVS:kickstart, an absolute location system where the A3000 system finds it on boot and copies it to RAM. These initial A3000s supported the inclusion of the Kickstart in both ROM and floppy, although not simultaneously. An A3000 configured to use kickstart images on disk has the benefit of being able to boot from various versions of AmigaOS with high compatibility levels, simply by selecting the appropriate image at boot.

The Commodore CD-TV included ROMs with additional firmware that is not technically part of the Kickstart. The original firmware ROM of the CD-TV must be updated to install a Kickstart version later than 1.3.

The AmigaOS 2.1 is just a software update and does not have a corresponding set of ROM chips. Workbench 2.1 works on all 2.0x family Kickstart ROMs. Later versions of the AmigaOS (3.5 and 3.9) are also software-only updates and do not include corresponding ROMs, requiring the 3.1 Kickstart instead. Starting with version 3.5 of the AmigaOS, a system of components based on a ROM file is used to replace the ROM chips.

Versions

We found the following versions of the Kickstart: