eCos might be a more worthy porting target. For starters, there's already a 68k port, albeit for later embedded 68ks, and it is currently developed, supported, and deployed.
http://en.wikipedia.org/wiki/ECos
eCos (embedded configurable operating system) is an open source, royalty-free, real-time operating system intended for embedded systems / It is designed to be customizable / programmed in the C programming language, and has compatibility layers and APIs for POSIX and µITRON./
eCos was designed for devices with memory size in the tens to hundreds of kilobytes / It can be used on hardware with too little RAM to support embedded Linux /
eCos runs on a wide variety of hardware platforms, including / Motorola 68000 / PowerPC /
eCos Porting Guide
One of the key aspects of eCos is its configuration system. It allows the programmer to control what functionality and features are included at runtime. Selecting from package modules, the programmer can layer different functionality, such as an Ethernet driver and networking support or a different scheduling algorithm, according to the needs of the application. Unwanted features can be eliminated easily to reduce the resource footprint. The configuration system also enables developers to employ third-party components to extend and enhance the functionality of the operating system.
eCos was designed for portability to a wide variety of 16-, 32-, and 64-bit processors and platforms. eCos is assembled from different components layered on each other to add the needed support for a given system. The base of this layered architecture is the hardware abstraction layer (HAL). Once the HAL has been ported to run on a given target's processor and any specific configuration needed for the target platform itself is added, eCos can be up and running quickly.
The only
M68k port I can find is for the Coldfire. As I understand it from others' comments here, the Coldfire ISA is a
subset of that for 680x0s, so my very rough guess is that a backport would be feasible. There would probably be a
lot of custom coding involved to get peripheral device support (ethernet, serial, video, SCSI etc)
Course, you could just stick a IIe PDS card into a Mac and run Contiki on that :rambo:
