1.1. Objectives

In previous work, we performed validation, performance and robustness testing of the TenDRA technology to ensure its capability to implement and fully bootstrap a UNIX-like operating system. We also provided an assessment of the capability of TenDRA technology to express a fully portable operating system implementation. This work was very successful, and the results are reported in a summary report.

However, though we originally planned to conduct this first experiment on two different architectures, an Intel/486 and a Sun/Sparc platforms running UnixWare, it was completed only for the Intel/486 platform. After discussions with DRA, it was then decided to focus the second part of the project on the Unix commands, and to switch from the UnixWare to the Linux operating system. The motivations for a revised plan were:

• OSF is developing a Linux server for the Intel/486 and PowerPC platforms, and we would like to deliver the set of associated commands in ANDF format. In the event, native Linux commands for PowerPC became available in the meantime.

• Repeating on the Sparc platform the work already done on the i486 platform would bring little added-value, while requiring a significant amount of work. The major benefit of the work on a second platform would be to demonstrate that a set of commands along with its API can be defined in ANDF format and then installed on two different platforms.

Thus, the objective of the second part of the project is the production in ANDF format of Linux commands, and their installation on two platforms. This will demonstrate the ability of the TenDRA technology to produce a set of architecture neutral commands and, at completion of the project, will provide a set of freely distributable commands in ANDF format.

The project, which lasted 9 months, started on July 1995, and was finished at the end of March 1996.

This report summarizes all the work done under the contract for this second part of the project.

1.2. General description

The commands, one part of a Unix system, are based on some standard APIs, XPG3 for example, plus some extensions, which together form the interface shared with the libraries against which they are built. The commands should not have any assembly code, unlike the other parts of a Unix system.

As for other software OSF already ported to ANDF, the port of the Linux commands is done in three steps:

• The NAT-NAT step, which consists in rebuilding the commands with the native compilation chain, to ensure that they can be regenerated from their source files.

• The DRA-NAT step, for which the TenDRA technology is used as a replacement of the native compilation chain to build the commands, using the native system header files, as for a classical compilation chain. This part involves dealing with discrepancies between the native and the TenDRA code generators.

• The DRA-DRA step, which will consist in using the TenDRA technology as a portability tool. The API shared by the commands and libraries is defined, and used to produce the commands in architecture independent ANDF code. This code will be installed and validated on the selected machines.

We initially planned to conduct the experiment on the Intel/i386 and IBM/PowerPc platforms, both running the Linux operating system. However, the Linux system for the IBM/PowerPC platform was still under development at the time we needed it, in December 1995. So we decided to replace it by a Digital/Alpha platform, the only other platform for which a Linux port was sufficiently advanced at that time. However, it is a 64-bit platform, so this switch was more of a challenge, because of the fundamental change in data sizes. It provided additional tests of the TenDRA portability attributes.