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June 28, 1991
Dear Colleague:
We are happy to send you information about our June, 1991 update to our 1988 networking release. This software is copyrighted by the University of California and others, but may be freely redistributed. It is available to anyone and requires no previous license, either from AT&T or The Regents of the University of California. The license agreement is similar to that of the first BSD Networking Release; however, this version includes much additional software that is not network-related. The new release contains those portions of the 4.3BSD-Reno release that are available for distribution without other licenses, as well as new material that has been written or contributed since the Reno release. Although many portions of this release have been written or integrated only recently, and thus have not been well tested, we have received numerous requests for these portions of the system. Therefore, we are providing this release as an experimental test release for interested developers. The distribution includes both software developed at Berkeley and also a large amount of software contributed by authors outside of Berkeley (for details, see the attached contributors list).
This packet is designed to serve two purposes. The first is to acquaint you with the details of our distribution so you may decide if you wish to purchase it. The second purpose is to tell you how to obtain our distribution.
Distribution contents"The distribution is a source distribution only," "and does not contain program binaries for any architecture." Thus, it will not be possible to compile or run this software without a pre-existing system that is already installed and running. In addition, the distribution does not include sources for a complete system. It includes source code and manual pages for the C library and approximately three-fourths of the utilities distributed as part of 4.3BSD-Reno. An approximate list of the included and excluded utilities is provided in the attached utilities list.
Additionally, the distribution includes source code for most of the 4.3BSD-Reno kernel, including machine support for the HP9000/300 series (Motorola 680x0-based machines) and for PCs built by Compaq and others (Intel 386/486-based machines with ISA/AT or EISA bus only). A limited number of device drivers are provided. The distribution does not include the machine support for the Tahoe and VAX architectures found in the standard BSD distributions. "The kernel source code is not complete for any architecture." Specifically, the kernel support for executing files, doing physical I/O, managing the buffer cache, handling process tracing and doing accounting is not included for licensing reasons.
"This software distribution is provided on 1/2'' 9-track tape" "and 8mm cassette only." The distribution is available on a single 6250 BPI 9-track tape, one 8mm Exabyte cassette, or on three 1600 BPI 9-track tapes. No other media are currently available.
This distribution represents an intermediate point in the development of 4.4BSD; several new facilities have been completed and are ready for external testing, while other new facilities slated for the 4.4BSD release have not yet been integrated. The major addition since the 4.3BSD-Reno release is the replacement of the 1979 vintage virtual memory system with a virtual memory implementation derived from Carnegie-Mellon's MACH operating system. The kernel sources have been reorganized to collect all machine-dependent files for each architecture under one directory, and most of the machine-independent code is now free of code conditional on specific machines. The user structure and process structure have been reorganized to eliminate the statically-mapped user structure and to make most of the process resources shareable by multiple processes. The kernel has been converted to be compatible with ANSI C, including function prototypes for many of the exported functions.
Intended audience for this distributionThis release is intended for system developers and others who wish to preview or experiment with the most recent Berkeley system. It may also be useful as an update to earlier BSD or BSD-derived systems, although substantial work will be required to integrate portions of this release into older systems. This distribution is not intended to be used on production systems, nor is it intended for sites without sufficient expertise to find and fix problems that are encountered. It is not suitable for the home hobbyist wishing to run BSD on a 386 PC. It is intended to be used to provide an advance look at some of the facilities and interfaces that we will be distributing in 4.4BSD. Our goal in making this release available is to obtain feedback on problems in the design or implementation of these facilities and interfaces. This distribution will allow adventurous sites to gain experience with the new framework and to provide input as it evolves into 4.4BSD. Because many of the oldest and most stable parts of the system have been replaced to eliminate proprietary code, this software is not as stable, reliable or well documented as most BSD distributions. Much of the work to be done between now and the 4.4BSD distribution is release engineering and documentation.
Only limited support will be provided by our group. Specifically, we cannot provide help with installation of this software on other systems. We are, of course, interested in getting feedback on problems that you encounter in this release. Some of the interfaces in this release will change before the release of 4.4BSD (in part based on feedback from this test group). Therefore, you should not depend on applications ported to this release working unchanged on 4.4BSD. We appreciate your help in this debugging effort and look forward to hearing from you. Please send your comments to net2-bugs@Berkeley.EDU.
The code in this distribution may be redistributed and used in released products. However, you are strongly encouraged to upgrade any code that you use from this distribution to the similarly-licensed distribution of the 4.4BSD code within one year of its release.
Summary of changes since the first networking distributionWe regret that changes documents are not available; this section outlines the major changes. In addition to the inclusion of a much larger portion of the BSD system, there are four major new kernel facilities available in this release. They are ISO/OSI networking support, a freely-redistributable implementation of UFS and NFS, a new virtual memory implementation, and the conversion to and addition of the POSIX.1 facilities. There are numerous other changes throughout the system.
The ISO/OSI Networking consists of a kernel implementation of transport class 4 (TP-4), Connectionless Network Protocol (CLNP), and 802.3-based link-level support (hardware-compatible with Ethernet\(dg). .FS \(dgEthernet is a trademark of the Xerox Corporation. .FE The session and presentation layers are provided outside the kernel by the ISO Development Environment (ISODE). Included in this development environment are file transfer and management (FTAM), virtual terminals (VT), a directory-services implementation (X.500), and miscellaneous other utilities.
A new virtual filesystem interface has been added to the kernel to support multiple filesystems. Although generally similar to Sun Microsystems' vnode interface, the Berkeley interface has been structured for more efficient support of filesystems that maintain state (such as the local filesystem). In addition to the local ``fast filesystem'' (UFS), we have added an implementation of the network filesystem (NFS) from the University of Guelph that fully interoperates with the NFS shipped by Sun and its licensees. Because this NFS implementation was done using only the publicly available NFS specification, it does not require a license from Sun for use in source or binary form. It runs over UDP to be compatible with Sun implementation by default, however, it can be configured on a per-mount basis to run over TCP. Using TCP allows it to be used quickly and efficiently through gateways and over long-haul networks. We have also added a memory-based filesystem that runs in pageable memory, which allows large temporary filesystems without requiring dedicated physical memory.
The quota system has been rewritten to support both user and group quotas (simultaneously if desired). Quota expiration is based on time rather than the previous metric of number of logins over quota. This change makes quotas more useful on fileservers onto which users seldom login.
The new virtual memory implementation is derived from the MACH operating system developed at Carnegie-Mellon, and was ported to the BSD kernel at the University of Utah. The MACH virtual memory system call interface has been replaced with the ``mmap''-based interface described in the ``Berkeley Software Architecture Manual'' (see UNIX Programmer's Manual, Supplementary Documents, PS1:6). The interface is similar to the interfaces shipped by several commercial vendors such as Sun, Convex Computer Corp. and AT&T. The integration of the new virtual memory is functionally complete, but still has serious performance problems under heavy memory load. The internal kernel interfaces have not yet been completed and the memory pool and buffer cache have not yet been merged. These changes are expected before the release of 4.4BSD.
This distribution contains most of the interfaces specified in the POSIX.1 system interface standard. The biggest area of change is a new terminal driver. The terminal driver is similar to the System V terminal driver with the addition of the necessary extensions to get the functionality previously available in the 4.3BSD terminal driver. This distribution also adds the POSIX job control interface, which is similar to the 4.3BSD job control interface, but adds a security model that was missing in the 4.3BSD job control implementation. Other additions include POSIX signals, FIFOs, byte-range file locking, and saved user and group identifiers.
There are a number of new tools and utilities included in this release. A new version of make allows much-simplified makefiles for the system software and allows compilation for multiple architectures from the same source tree (which may be mounted read-only). Notable additions to the libraries include functions to traverse a UNIX file hierarchy, database interfaces to btree and hashing functions, a new, fast implementation of stdio and a radix sort function. The additions to the utility suite include greatly enhanced versions of programs which display system status information, implementations of various tools traditionally found in System V releases and many others.
We have been tracking the POSIX 1003.2 shell and utility work and have included prototypes of many of the proposed utilities. Because most of the traditional utilities have been replaced to eliminate code proprietary to AT&T, you should realize that the utility software may not be as stable, reliable or well documented as in traditional Berkeley releases. In particular, almost the entire manual suite has been rewritten to be freely redistributable and, in many instances, it does not correctly reflect the current state of the software. It is also worth noting that, in rewriting this software, we have generally been rewarded with significant performance improvements. Most of the libraries and header files have been converted to be compliant with ANSI C. The default compiler (gcc) is compatible with ANSI C, but supports traditional C as a command-line option. The system libraries and utilities all compile with either ANSI or traditional C.
Work has also progressed in several other areas. Several important enhancements have been added to the TCP/IP protocols including TCP header prediction and serial line IP (SLIP) with header compression. The routing implementation has been completely rewritten to use a hierarchical routing tree with a mask per route to support the arbitrary levels of routing found in the ISO protocols. The routing table also stores and caches route characteristics to speed the adaptation of the throughput and congestion avoidance algorithms.
The Kerberos (version 4) authentication software has been integrated into much of the system (except NFS) to provide the first real network authentication on BSD.
The hardware supported is:
The reason that this distribution is not considered an alpha release of 4.4BSD is because it does not contain several major interfaces that we plan to have available for that distribution. These include:
This release does include several important structural kernel changes. The kernel uses a new internal system call convention; the use of global (``u-dot'') variables for parameters and error returns has been eliminated, and interrupted system calls no longer abort using non-local goto's (longjmp's). A new sleep interface separates signal handling from scheduling priority, returning characteristic errors to abort or restart the current system call. This sleep call also passes a string describing the process state, which is used by the ps(1) program.
Many data structures that were previously statically allocated are now allocated dynamically. These structures include process structure entries, user and system file tables, the mount table, the vnode table, the name cache, and the quota structures.
How to obtain this softwareThe following procedure is necessary to obtain this software and license from Berkeley. As the software is freely distributable, you may also obtain part or all of this release from other sites.
Before the distribution can be sent, we require:
All the above material must be sent to: Pauline Schwartz, Distribution Coordinator Computer Systems Research Group Computer Science Division, EECS University of California Berkeley, California 94720 Once these three items have been received and are in proper order, the distribution will be sent to the technical address given on the Site Information Form. We cannot provide delivery dates. Once the material is assembled and packaged, the distribution is shipped by commercial carrier. Order of shipment will be based on time of arrival of the properly completed paperwork. Because of the differential in costs of shipping outside the United States, we ask that organizations outside the continental United States pay the collect shipping charges.
The most expedient way to insure that your full distribution is sent as quickly as possible is to include, in a single package, two copies of the completed and properly signed BSD Networking Software, Release 2 License Agreement (without modification) with Exhibit A, the check properly made out to ``The Regents of the University of California, Computer Systems Reseach Group,'' and a completely filled out Site Information Form, and to send this single package to the address noted above.
Please note that if you modify the BSD Networking Software, Release 2 License Agreement, you may experience a delay of three months or more before receiving an acceptance or denial of the changes. We reserve the right to cancel your application if we have not received the requested paperwork within 60 days from the date of our request.
Special CasesUniversity of California Sites. If you are a part of the University of California, you must send the following items to the Computer Systems Research Group: 1) a letter signed by the Director or Head of Department requesting this distribution and stating that you have read and understood the BSD Networking Software, Release 2 License Agreement and that your organization will abide by it, 2) an IOC for $850.00 for a single 6250 BPI tape or 8mm Exabyte tape or $950.00 for two 1600 BPI tapes, and 3) a Site Information Form.
A Special NoteThe procedures and rules set out in this document are University constraints that must be followed in order for the distribution of software to be possible. The Computer Systems Research Group has no control over these constraints and must reject your application if material submitted is not in order.
If You Have Read Everything and Still Need HelpIf you have questions about the licensing process after reading this letter, you may contact Pauline Schwartz via electronic mail at either bsd-dist@CS.Berkeley.EDU or uunet!bsd-dist@CS.Berkeley.EDU, or call her at 415-642-7780. She will not be able to answer technical questions. Sincerely yours, Marshall Kirk McKusick
Computer Systems Research Group