3. Requirements to run Linux/m68k

3.1 Processor

You need a Motorola 680x0 processor with a programmable memory management unit (PMMU). There is no way to run it without one. This reduces the list of possible processors to 68020+68851, 68030, 68040, 68LC040, and 68060. This list of processors excludes the 68000, 68010, 68EC020, 68EC030, and 68EC040. It also excludes the CPU32 processors (683x0 series) and the ColdFire processor. Linux/m68k can never run on these processors as they lack a PMMU and an interface for an external one (some 68EC030s do have a functioning PMMU and will run Linux; however, their long-term reliability is questionable since Motorola never tested the PMMU). Consequently, all Linux/m68k software is compiled for 68020 or higher CPUs.

The following Amigas have the ``right'' processor built-in: A2500, A3000, A3000T, A4000/040 (not the A4000/030, which ships with a 68EC030 processor, unless upgraded with an 040 or 060), A4000T/040 and A4000T/060. There has been a report that the last A4000/040s produced by Commodore were shipped with 68LC040's. In that case, you will need a kernel with FPU emulation compiled in (see FPU emulation for current information).

The following Ataris (or clones) have the ``right'' processor built-in: Atari Falcon, Atari Falcon with Afterburner 040, Atari TT, and Medusa. The standard Falcon does not have an FPU built-in. In this case you will need a kernel with FPU emulation compiled in. Any processor upgrade card with a 68030 or 68040 (like the PAK/3 with or without 68881 or 68882) is able to run Linux.

Notes:

1. In some of the older TTs there is a bug in the PAL controlling the access to the FPU. This may cause crashes (see Known Bugs).
2. On the Amiga, there exists a program called ``lawbreaker'' (part of the Enforcer package). This program allows you to check whether you have a working PMMU or not (it needs to generate 5 hits in combination with Enforcer, where the last one is an alert).
3. Some 68LC040's were shipped that had bugs in the FPU emulator trap, which makes FPU emulation not work correctly. My understanding is that Motorola will swap defective chips for working units; if you purchased your computer from Apple, they apparently are offering a similar deal.

3.2 RAM

It is possible (but very difficult) to boot Linux/m68k with as little as 2 MB. Now you know that the kernel works on your system: that's it. If you want to work with it you should have at least 4 MB (8 MB is probably the working minimum if you want to run an X server).

Notes:

• On the Amiga only the size of your Fast RAM is relevant. The Chip RAM is only used internally for graphics, sound and floppy data; it is not used by normal programs.
• If you have an Amiga with 16-bit expansion RAM on a Zorro card, see 16-bit RAM.
• On Ataris, ST RAM is usable on most systems.

3.3 Hard Disk

If you want to do more than just boot Linux/m68k you will need 60 MB or more of free space on your hard disk and a supported hard disk controller. Add another 20 MB of disk space to the base requirements to use X.

In addition, you'll need some swap space. Any amount will do (and you will need less if you have more RAM). 16 MB of swap space is a fairly reasonable size for most systems.

3.4 Software

Amiga: In order to run amiboot you need AmigaOS 2.0 or higher (expansion.library V36 or later).

Amiga: amiboot works with SetPatch and RsrvMem (part of Emplant) running. Additionally, you can start amiboot with VMM running (see Known Bugs for how to do this).