The SmAS project requires a minimal operating system oriented towards its needs. This means that we need only a kernel with basic functionality. In brief this functionality is:

• Basic hardware support
• Memory management
• Process management
• File management
• Networking

The hardware required by SmAS is a hard disk drive and an ethernet card, so the operating system should provide support for IDE/SCSI and ethernet interfaces. Of course for our convinience the operating system will also provide terminal support. The memory needs of the SmAS project are covered by a basic memory manager that doesn't provide swapping or even virtual memory facilities. Also the memory allocation algorithm could be as simple as first-fit. However the SmAS operating system implementation can support virtual memory for future use. Process management can be as trivial as first-come first-server, preemptive algorithms thought can add a significant performance boost so they will be supported by the SmAS operating system. The SmAS system requires severe file operations so a full featured file system should be supported, such as ext2fs. The SmAS concept encapsulates distrubuted calculation concepts and distrubution of information through a network is its primary task. The best choice is an operating system that supports the TCP/IP protocol family.

In addition various other services are required such as dynamic library and ELF executable loading are required by the SmAS operating system and are not described here.

Project Status

The research for the SmAS operating system is focused on the choice of an existing system kernel as a starting point and the integration of SmAS in this kernel. Our efforts have turned towards GNU's operating system kernel the HURD. Currently our purpose is to embed the SmAS system in the HURD implementing a kernel server.

The HURD

THe HURD is a modern kernel that supports a wide range of facilities found in these systems This choice was made for a number of reasons.

• The HURD source code is distributed under the GPL license. This means, more or less, that we can use and modify the code at will as long as our software is distributed under the same license.
• The HURD system architecture is build on top of the GNU/MACH microkernel providing an independence from hardware and a modular structure.
• The objected oriented approach of a kernel used in HURD, suits our needs as eases the modification of the kernel. Specifically the HURD consists of a number of kernel servers handling all functionality and communicating with messages.

The SmAS operating system is been researched by

Kinalis Athanasios, csst9730@cs.uoi.gr

an undergraduate student at Computer Science Department of the University of Ioannina working on his degree thesis.