1. eric_j
  2. oskit

Overview

		The OSKit - Flux Operating System Toolkit
		   Version 0.97 - January 15, 1999

		Snapshot 20020317 - March 17, 2002
		 


For major changes since release 0.96 in Dec. 1998 see the file ./ANNOUNCE

INTRODUCTION
This is the top level directory of the source distribution of the OSKit.  The
OSKit is a framework and a set of 31 component libraries oriented to operating
systems, together with extensive documentation.  By providing in a modular way
not only most of the infrastructure "grunge" needed by an OS, but also many
higher-level components, the OSKit's goal is to lower the barrier to entry to
OS R&D and to lower its costs.  The OSKit makes it vastly easier to create a
new OS, port an existing OS to the x86 (or in the future, to other
architectures supported by the OSkit), or enhance an OS to support a wider
range of devices, file system formats, executable formats, or network services.
The OSKit also works well for constructing OS-related programs, such as boot
loaders or OS-level servers atop a microkernel.

For language researchers and enthusiasts, the OSKit lets them concentrate on
the real language issues raised by using advanced languages inside operating
systems, such as Java, Lisp, Scheme, or ML--- instead of spending six months
first writing boot loader code, startup code, device drivers, kernel printf and
malloc code, a kernel debugger, etc.  With the recent addition of extensive
multithreading and sophisticated scheduling support, the OSKit also provides a
modular platform for embedded applications, as well as a novel component-based
approach to constructing entire operating systems.  See doc/html/roadmap.html
for a quick overview of the components.


SOME COOL EXAMPLES
With the code available from www.cs.utah.edu/projects/flux/oskit/kaffe/
the highly portable Kaffe JVM from www.transvirtual.com "just works" on the
bare PC hardware using the OSKit.  Yes, a "Java OS"-- but you can also
reconfigure the OSKit to run Kaffe/OSKit on top of Unix, which is great for
debugging.  Almost all the changes are already merged into the mainline Kaffe
tree.  (Note the restriction that currently the only display support for Kaffe
kernels is to use the OSKit's xclient support to display on another machine
that runs an X server.)  On our ftp site in flux/oskit/doom, we also provide
patches for Doom, to get a "DoomOS."


DOCUMENTATION
See ANNOUNCE for more quick answers.  For the latest versions of
those files, look at www.cs.utah.edu/projects/flux/oskit/.  Detailed
instructions on how to install and use the OSKit are contained in Chapter One
of the document in the `doc' subdir.  Text, Postscript, and 2-up Postscript of
the 500-page document are in doc/oskit.*.gz.  An HTML version is here at
doc/html/index.html as well as at www.cs.utah.edu/projects/flux/oskit/doc/.

Don't let the size of the doc scare you!  You probably won't need to read
practically any of it to use the OSKit for simple things.  We provide some 45
small example kernels and recommend that you start learning by example and by
doing (modifying them), like most good hackers do, and read to fill in
details, for reference, or to cure insomnia.  However, reading Chapter One of
the doc is a very good idea, especially the roadmap, doc/html/roadmap.html.
Also, you might scan the top-level directories and the examples.  Each
directory should have a README.  Finally, the CREDITS file gives just that.


--------------------------------------------------------------------------

Requirements:

1) Hardware: The OSKit requires an Intel 486 PC or above, with at least
   four MB of memory. A floppy or hard disk is required to load OSKit
   kernels (at least the first one; see "netboot" below), but is not
   required to run them.

2) Software: native build environment for either Linux or FreeBSD.
   The latest snapshot has only been tested with the default build
   environments provided with FreeBSD 4.3/4.5 and Red Hat Linux 7.1/7.2.
   In particular, we have not done any testing with GCC 3 releases.
   Cross building is possible and it's been done frequently on HP machines.
   Build tools required are GNU make, gcc 2.7.x or 2.95.x and binutils 
   2.8.x or 2.9.x.

3) A boot loader that can load one of Linux, Mach, BSD, or
   MultiBoot-compliant images.  (Our DOS loader is current broken;
   see the BUGS file.)

4) The GNU linker is required if creating BSD/Mach boot images on FreeBSD 2.x
   (available at ftp://flux.cs.utah.edu/flux/oskit/boot/bsd/).

---------------------------------------------------------------------------

Configuring and building step-by-step:

The OSKit follows the GNU conventions for configuration, building, and
installation. The "configure" script in the top level directory will
attempt to guess your system type and locate various required tools
such as the C compiler. You can configure the OSKit to build itself in
its own source directory, simply by moving to that directory and
typing ./configure, or you can build the OSKit into a separate object
directory by changing to that directory and running the configure
script from there. The introductory section of the OSKit documentation
describes the OSKit specific options to configure in detail. As an
example, to configure the OSKit on a FreeBSD machine, generating a.out
format, you would run configure as follows:

  /somepath/oskit/configure --prefix=/somepath/install \
	--build=i586-freebsd --host=i386-mach

On Linux, building ELF format, you'd simply do:
	/somepath/oskit/configure --prefix=/somepath/install

Once the OSKit is configured, you can proceed to build the OSKit by
going to the directory you have chosen to build it in, and running GNU
"make" (e.g., just "make" on Linux systems, or "gmake" on BSD
systems). Once the build completes, you can 'make install' to make the
OSKit binaries and header files to make it publicly available.

Disk usage:

-Source and doc tree is 7.5M compressed, 30.5M uncompressed.
-ELF object tree without debug, without profile, without docs: 48M.
 The examples dir is 20M of that.
-ELF object tree with debug, without profile, without docs: 221M.

---------------------------------------------------------------------------

Using the OSKit:

The examples/x86 directory contains a number of example kernels that
you can use to experiment with the OSKit. The simplest example is the
"hello" kernel, which prints "Hello World" on the console, and then
reboots. If you have built the entire OSKit tree, the sample kernels
will have already been built. If not, go to the examples/x86 directory
and run GNU make.

The resulting hello binary conforms to the "multiboot" standard, and
is immediately ready to boot with a multiboot compliant loader such as
GRUB (www.uruk.org/grub/). You can also use the OSKit's "netboot" loader,
which can directly load multiboot images across the network. 

Other boot formats supported by the OSKit are Linux, Mach, and BSD (MS-DOS is
currently broken).  The conversion utilities supplied to convert from
multiboot format are "mklinuximage", "mkbsdimage", and "mkdosimage." These
utilities are automatically built and installed with the OSKit, when
configured for the appropriate host.  Due to the extra difficulty and delicacy
of building them they are also provided in binary form, in
ftp://flux.cs.utah.edu/flux/oskit/boot/.  As an example, to convert the
hello kernel into the format required by the BSD and Mach boot loaders:

	/somepath/install/bin/mkbsdimage hello

Note that by default, the resulting image is placed in a file called
"Image" in the current directory. This image can then be copied to the
root partition of your machine, and booted like any other kernel. In
the case of the hello kernel, it will simply print "Hello World",
exit, and then reset the machine (after waiting for a key press if
you're on the VGA console).

---------------------------------------------------------------------------

Netboot:

As an alternative, you can use the OSKit's NetBoot loader to load the
original multiboot image from across the network. The NetBoot loader is
contained in the boot/net directory, and will have been built along with
the rest of the OSKit. NetBoot is a small kernel that provides one
service: fast (re)booting of other multiboot compliant operating systems
across the network. There are several requirements for using NetBoot:

1) NetBoot itself must be in one of the accepted boot formats described
   above in order to load, and it must reside in the root directory of
   the machine being used to boot kernels.

2) NetBoot requires a BOOTP server to be running on the local network in
   order to obtain the IP address, gateway address, netmask, and
   hostname of the host it runs on. If no BOOTP server responds when
   NetBoot is booted, it will ask to retry or exit.

3) The files that NetBoot fetches and boots must reside in a directory
   that is NFS exported to the host running NetBoot.

If all of these requirements are satisfied, then you can boot the
hello kernel across the network as follows:

	Netboot: ipaddr:/somepath/examples/x86/hello

--------------------------------------------------------------------------

BSD Boot Support:

The easiest way to get BSD boot image support (boot/bsd) is to have a
linker on your path that is configured for both ELF and Mach formats.
That way, you can build your oskit with ELF tools, but write out an
I386Mach format adaptor that is suitable for the BSD loader. The best
approach we found is to take a vanilla binutils 2.9.1, and configure
it as follows (assuming a FreeBSD 3.0 system):

        /build/src/binutils-2.9.1/configure --prefix=/build/tools
                --target=i386-mach \
                --enable-targets=i386-mach,i386-unknown-freebsdelf3.0

Then setenv AOUT_LD to:

        /build/tools/bin/i386-mach-ld -m i386mach

Then configure and build your oskit, which will now include a bsd boot
adaptor directory, built with ELF tools of course. Then you can take an ELF
version of netboot (from the same build tree) and run it through a modified
mkbsdimage, which references a new linker script. This linker script does
the usual munging of sections and such, so that the output image actually
works. 

--------------------------------------------------------------------------

More sophisticated examples:

There are numerous example kernels, but we highlight just a few that
demonstrate more useful functionality. Pointers to the relevant sections
in the documentation are provided as well.

1) examples/x86/socket_com.c: This is a test program for the TCP/IP
   stack. It first does two fingers and then waits for incoming date
   requests. It is written to the Component Object Model (COM)
   interfaces for the TCP/IP stack. See the "OSKit Networking Framework"
   and "FreeBSD Networking" sections.

2) examples/x86/socket_bsd.c: Same as previous example, but is written
   to the oskit libc socket interface. See the "Minimal C Library" and
   "FreeBSD Networking" sections.

3) examples/x86/blkio.c: This is a program that illustrates the use of
   the block device drivers. It reads blocks of data from a disk, and
   optionally writes data to the disk. See the "Block I/O Interface"
   section. 

4) examples/x86/netbsd_fs_com.c: Illustrate the use of the NetBSD 
   filesystem code using the COM interfaces. An assortment of operations
   are performed, including reading and writing files, creating
   directories, looking up files, linking files, and renaming files. See
   the "Disk Partition Interpreter", "File Interface," "Directory
   Interface" and "Open File Interface" sections of the documentation.

5) examples/x86/dphils.c: This program illustrates the use of the POSIX
   threads package, solving the classic dining philosophers problem
   using monitors. See the "POSIX Threads" section of the documentation.

-------------------------------------------------------------------------

For known problems see the BUGS file.

-------------------------------------------------------------------------

Cross building:

It's been done at least under HPUX and under our BSD for HP's.
Should work in general.
	HPUX:
		config options: --target=i486-linux --host=hppa1.1-hp-hpux
		gcc 2.7.2, binutils 2.8.1
		[ had trouble building libgcc as I recall ]
	
--------------------------------------------------------------------------

Version Information:

The following is a list of the versions of software from which
the OSKit derives large chunks of code:

FreeBSD:	2.1.7.x (networking, glue), 2.2.2 (C and math libs)
NetBSD:		1.2
Linux:		2.0.29
x11:		XFree86 3.3.1
svgalib:	1.3.0
Mach:		basically what was our "mach4"

--------------------------------------------------------------------------

Contact Information:

Send comments, suggestions, bugs, and fixes to oskit-users@cs.utah.edu.

For messages just to the Utah developers send to oskit@flux.cs.utah.edu.

To be added to appropriate mailing lists, send mail to:
  oskit-users-request@cs.utah.edu		(oskit users/hackers)
  oskit-announce-request@cs.utah.edu		(major announcements only)
You do not have to be on both lists at once; mail to the announce list
also goes to the users list (but not vice versa, of course.)

Archives of the mailing lists are available in
  ftp://flux.cs.utah.edu/flux/oskit/mail/html/index.html	(HTML)
  ftp://flux.cs.utah.edu/flux/oskit/mail/index.html		(mbox)


Have fun!

The Flux Research Group
Department of Computer Science
University of Utah
http://www.cs.utah.edu/projects/flux/