Subject: Stack underflow on boot problem.
To: None <amiga-dev@sun-lamp.cs.berkeley.edu>
From: Markus Illenseer <markus@TechFak.Uni-Bielefeld.DE>
List: amiga-dev
Date: 07/05/1994 23:08:05
	For those who are using recent sups, there may be a stack underflow
	on boot that causes hangs. So far it's happened only on my 3000
	with a kernel compiled for '030's only, i.e. no FPSP or
	M68040 defined in the conf file.
	
	The symptoms are messages about an unknown trap at 0xe0,
	it's an '030/68551 "tried to put bad value in MMU register" trap.

	To get around it, add something like

	.long	0xdeadbeef

	between the

	tmpstk:

	and

	protorp:

	lines in locore.s. I'm trying to track down what causes the
	stack to underflow at boot out of the tmpstk area and clobbers
	the 0x80000002 value at protorp. For now adding a 1 word scratch
	value allows the system to boot and function.

	Not sure what all is causing this but for those playing with July
	sup's this hack may be needed to boot. Mucho thanks to Michel Hitch
	for pointers on tracking this down.

		-Rob

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