[TUHS] 4.4BSD installed image or login shell?

Jeremy C. Reed reed at reedmedia.net
Sat Apr 21 02:56:32 AEST 2012


On Fri, 20 Apr 2012, Nick Downing wrote:

> OK, I hadn't been aware of the significance of the 2 in 4.4BSD-Lite2, so
> I understand it contains a CSRG version of the startup code, etc that
> was originally from AT&T and was left out of 4.4BSD-Lite?  Is it
> anything to do with Jolitz's work on 386BSD?  Does it have anything
> else?  Searching threw up a few results on multiprocessor locking so
> maybe it contains additional features as well as just the missing code?
> cheers, Nick

It doesn't appear to include the needed code. From looking at huge diff, 
I don't see any additions identified from Jolitz/Telemuse/386BSD. (For 
example, Lite already had Jolitz i386 code and Lite2 only had minimal 
changes to the code.)  I quote from Cover.rel2 document for Lite2:

``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, approximately 
90% of the utilities distributed as part of 4.4BSD, and most of the 
kernel (the same subsystems that were deleted in Net/2 are still missing 
in 4.4BSD-Lite Release 2 (support for executing files, doing physical 
I/O, managing the buffer cache, handling process tracing, terminal 
character I/O, and doing accounting).''

The diff is huge. Lite2 has many changes: ``includes the copy editing 
work done for the Usenix/O'Reilly manuals as well as numerous bug fixes 
and enhancements that have been accumulated in the year since the 
release of 4.4BSD-Lite. Of particular interest are the changes needed to 
port the system to 64-bit architectures, important security enhancements 
to TCP/IP, and much improved functionality for the union and 
log-structured filesystems.'' (See 
http://mail-index.netbsd.org/current-users/1995/03/23/0008.html or the 
Cover.rel2 document.)   I think is also incorporates many changes 
already done by BSDI, NetBSD, and FreeBSD.

By the way, the TUHS page at 
http://minnie.tuhs.org/cgi-bin/utree.pl?file=4.4BSD lists some files 
removed to create Lite. Actually per filenames, only the sysv_shm.c and 
shm.h and cpio.c files were removed. (cpio replaced with pax.) All were 
modified.  (That TUHS page also has two mistakes: lists /sys/sys/buf.h 
twice and misspells /sys/ufs/inode.h as indode.h.)

The Restricted Files also listed: sys/kern/kern_physio.c, 
sys/kern/vfs_bio.c, and sys/sys/tty.h and they are still included in 
Lite. Probably because files were not included in historical AT&T code, 
because newer USL code did include them, lots rewritten and so if any 
code was reused it became insignificant and was agreed on.  vfs_bio.c 
was mentioned in a declaration stating is was based on published 
pseudo-code.

Where is the actual list of files missing in Lite (that are in 
Encumbered)?



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