March 19, 1997

Announcing the first update to MkLinux DR2.1.

The "DR2.1update1" update adds some functionality that has been available
in the WIP (work-in-progress) kernel/server pairs, but had not yet been put
into an update.

The update is available for anonymous ftp from ftp.mklinux.apple.com:

	ftp://ftp.mklinux.apple.com/pub/Updates/DR2.1update1/

or our various mirror sites, in the directory:

    .../Updates/DR2.1update1/

(Please be patient with the mirror sites, it may take them some time to
 mirror the update)

*** IMPORTANT NOTES ****

General
-------
This update consists of a new Microkernel and Linux Server.  The source
to these pieces is included, as well as the tools (and instructions) needed
to build them.


Bug Fixes
---------
We believe this update fixes the following bugs.  If any of these problems
still occur after you have installed the update, please let us know by
sending mail to bugs@mklinux.apple.com.  Use the Subject: "Bugs Recur After
DR2.1update1"

- printf messages from the mach microkernel should no longer pollute
  the console screen, they should be neatly logged by klogd.

- A bug was fixed in cd audio that could cause filesystem corruption
  on PCI powermacs.

- Should be able to boot on machines with more than about 90Mb RAM
  (if not, there's a work around, see below)


Enhancements
------------

- Initial SCSI tape support.   The tape device doesn't have the usual
  naming convention.  It is named as per the SCSI ID, so if the tape
  has SCSI ID 4, the tape devices will be /dev/st4 and /dev/nst4

  We've tested the tape using 'tar' and 'taper' (which required a simple
  fix to the config to build on a big-endian machine), please let us know
  of any problems you see.


Work Arounds
------------

- PCI (604 processor) users with fast/slow clocks:
  Until we have a better method, you may now specify the bus frequency of
  your machine in your lilo.conf file.  Boot MacOS, go to the mklinux
  control panel, click on 'custom' and add the following to the end of
  the mach_options line, with a space beforehand: " bus_speed_hz=44000000"
  ie. you'll have a line like:
	mach_options= bus_speed_hz=44000000

- For users with ATI cards, and users for whom DR2.1 freezes at boot

  The "probe" for the ATI card that exists in the DR2.1 kernel causes
  some problems for machines that do not have ATI cards.  Therefore,
  the probe (and support for the ATI card) must be enabled with a mach
  option.

  To enable probing for ATI cards users will now need to add the option:
  " video_probe=true" to the end of the mach_options line (like above).

  It is possible to have a line like:
	mach_options= bus_speed_hz=44000000 video_probe=true

- If you've got "too much" memory (more than 90Mb), and MkLinux won't boot,
  you can tell the kernel to ignore some of it.  Use the mach option -m,
  such as "-m90" (to limit the kernel to 90 megabytes).

  Adding this in, you can now have a line like:
	mach_options=-m90 bus_speed_hz=44000000 video_probe=true


Quick Guide to Files Available in the DR2.1update1 Directory:
-------------------------------------------------------------

      README
	contains this message.

      README.install
	How to install the Mach Kernel and Linux Server

      README.build
	How to build the Mach Kernel and/or Linux Server

      Mach_Kernel.gz
      vmlinux.gz
	The Mach Kernel and Linux Server in gzipped (ie. compressed) form

      DR2.1update1.osfmk.src.tgz
	Sources to Mach Kernel in gzipped tar format.
	(to extract: tar -zxpf DR2.1update1.osfmk.src.tgz)

      DR2.1update1.osfmk.export.tgz
	The export/powermac directories, which contains the "exportable"
	pieces of the Microkernel build (include files and libraries)
	(to extract: tar -zxpf DR2.1update1.osfmk.export.tgz)

      DR2.1update1.mklinux.src.tgz
	Sources to the Linux Server update in gzipped tar format.
	(to extract: tar -zxpf DR2.1update1.mklinux.src.tgz)

      DR2.1update1.tools.tgz
	Various "Mach tools" that are needed to build both the microkernel
	and the Linux server.

      ode-bin.tgz
	OSF development environment tools that are needed to build the
	microkernel.