The ARC specific portion of the OpenBSD 2.1 release is found in the
"arc" subdirectory of the distribution.  That subdirectory is laid
out as follows:

.../2.1/arc/
		INSTALL.arc	Installation notes; this file.

		bsd.rd		ARC RAMDISK kernel. This is the
				kernel that should be booted when
				installing OpenBSD.

		*.gz		ARC binary distribution sets;
				see below.

		bsd		ARC GENERIC kernel in ELF format.
				This is the kernel installed by the
				install script.

		bsd.ecoff	ARC GENERIC kernel in ECOFF format.
				This kernel may be used to boot a
				system from a MSDOS disk.

The ARC ramdisk image is a bootable kernel+rootimage. This kernel is used
when a system is installed for the first time. The file is in ECOFF format.

The OpenBSD/arc binary distribution sets contain the binaries which
comprise the OpenBSD 2.1 release for ARC systems. There are seven binary
distribution sets.  The binary distribution sets can be found in
subdirectories of the "arc/bins" subdirectory of the OpenBSD 2.1
distribution tree, and are as follows:

	base21	The OpenBSD/arc 2.1 base binary distribution.  You
		MUST install this distribution set.  It contains the
		base OpenBSD utilities that are necessary for the
		system to run and be minimally functional.  It
		includes shared library support, and excludes
		everything described below.
		[ 15.0M gzipped, 50.9M uncompressed ]

	comp21	The OpenBSD/arc Compiler tools.  All of the tools
		relating to C, C++, and FORTRAN (yes, there are two!).
		This set includes the system include files
		(/usr/include), the linker, the compiler tool chain,
		and the various system libraries (except the shared
		libraries, which are included as part of the base
		set).  This set also includes the manual pages for all
		of the utilities it contains, as well as the system
		call and library manual pages.
		[ 15.9M gzipped, 60.2M uncompressed ]

	etc21	This distribution set contains the system
		configuration files that reside in /etc and in several
		other places.  This set MUST be installed if you are
		installing the system from scratch, but should NOT be
		used if you are upgrading.  (If you are upgrading,
		it's recommended that you get a copy of this set and
		CAREFULLY upgrade your configuration files by hand.)
		[ 92K gzipped, 450K uncompressed ]

	game21	This set includes the games and their manual pages.
		[ 2.9M gzipped, 7.5M uncompressed ]

	man21	This set includes all of the manual pages for the
		binaries and other software contained in the base set.
		Note that it does not include any of the manual pages
		that are included in the other sets.
		[ 2.5M gzipped, 9.4M uncompressed ]

	misc21	This set includes the system dictionaries (which are
		rather large), the typesettable document set, and
		man pages for other architectures which happen to be
		installed from the source tree by default.
		[ 1.8M gzipped, 6.2M uncompressed ]

	text21	This set includes OpenBSD's text processing tools,
		including groff, all related programs, and their
		manual pages.
		[ 1.0M gzipped, 4.2M uncompressed ]