NetBSD/sparc 1.4.2 README file

	1. boot floppies built from release sources are DOA.

	The install kernels in the release sources have grown just enough
	to break the memory layout used by the default sparc bootloader.
	Due to the vnd problems described in item #3, the correct set of
	changes wasn't known until after code freeze, and the sources that
	are distributed will produce boot floppies that fail in some way.

	Ironically, a set of alternate boot loaders to accomodate large
	kernels is now provided (and used), but is not actually needed by
	the final kernel images. While rebuilding to pick up the bug fixes
	described in #2 (below), it was discovered that the larger ramdisk
	had shrunk and a smaller area could be reserved in the INSTALL
	kernel. This reduced the INSTALL kernels just enough for the
	existing sparc boot loader to handle them.

	2. kernels built from release sources DOA on SparcStation 1 and ELC.

	Kernels built from release sources have been observed to crash on
	a SparcStation 1 while attaching the keyboard, and on a SparcStation
	ELC at approximately the point where bwtwo gets attached. Fixes for
	these have been applied to the GENERIC and INSTALL kernels provided.

	3. severe problems observed when using vnd devices on IPX (sun4c).

	The IPX build machine has been unable to reliably build boot
	floppies without crashing for the last few weeks of the release.
	A Sparcbook 3gx (sun4m) booting from the same hard drive succeeded
	however, and was used to produce the final bootfs images (which
	tested successfully on both machines).

	The symptoms are that use of vnd0 in src/distrib/sparc/ramdisk/...
	often fails, either by panic'ing the machine or by causing further
	attempts at disk I/O to never complete (resulting in slow creeping
	uselessness for all processes). For some reason it never happens
	with "miniroot" or "ramdisk.sysinst", only with "ramdisk".

	Evidence gathered so far suggests that either the build IPX is
	going senile or a latent bug in 1.4.x was tickled by changes to the
	release branch between 20000127-UTC and 20000225-UTC. However, due
	to the inconsistent reproducibility of the bug, this is not proven.
	"It's one of those bugs that doesn't always hit unless you really
	need things to work just one more time."

	4. INSTALL.html generated with "latin1" character set, not ASCII.

	5. file-system UNION disabled in GENERIC* kernels for security reasons.

	Due to concerns about known security exploits using the UNION file
	system, it has been disabled in the shipping kernels.


	The LAST_MINUTE file contains diffs for all of the above.

	Todd Whitesel
	toddpw @ netbsd.org
	Thu Mar 16 16:53:29 PST 2000