Fatal trap 12 during boot of 5.3-BETA7 installation CD

I've got a Compaq Presario S3500CL desktop machine and every time I boot the
5.3-BETA7 miniinst installation CD (or the disc1 installation CD), I get a
Fatal trap 12 after the floppy drive controller is detected.  This Fatal
trap occurs at the same instruction pointer no matter if I boot with or
without ACPI.

I've never reported a kernel Fatal trap before, but after searching through
the mailing list for similar crashes, I noticed most people submit the
following information.  If I can provide more detailed information, please
let me know.

Here's the kernel output when performing a normal boot:

OK boot
/boot/kernel/acpi.ko text=0x3f978 data=0x1be4+0x110c
syms=[0x4+0x72a0+0x4+0x9743] Copyright (c) 1992-2004 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
	The Regents of the University of California. All rights reserved.
FreeBSD 5.3-BETA7 #0: Sat Oct  2 21:01:00 UTC 2004
    root_at_wv1u.samsco.home:/usr/obj/usr/src/sys/GENERIC
ACPI APIC Table: <IntelR AWRDACPI>
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Pentium(R) 4 CPU 2.66GHz (2666.20-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0xf27  Stepping = 7
 
Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA
,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
real memory  = 536805376 (511 MB)
avail memory = 511549440 (487 MB)
ioapic0 <Version 2.0> irqs 0-23 on motherboard
npx0: [FAST]
npx0: <math processor> on motherboard
npx0: INT 16 interface
acpi0: <IntelR AWRDACPI> on motherboard
acpi0: Power Button (fixed)
Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x408-0x40b on acpi0
cpu0: <ACPI CPU> on acpi0
acpi_button0: <Power Button> on acpi0
pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0
pci0: <ACPI PCI bus> on pcib0
agp0: <Intel 82845G host to AGP bridge> mem 0xd0000000-0xd3ffffff at device
0.0 on pci0
pcib1: <PCI-PCI bridge> at device 1.0 on pci0
pci1: <PCI bus> on pcib1
pci1: <display, VGA> at device 0.0 (no driver attached)
uhci0: <Intel 82801DB (ICH4) USB controller USB-A> port 0xd800-0xd81f at
device 29.0 on pci0
uhci0: [GIANT-LOCKED]
usb0: <Intel 82801DB (ICH4) USB controller USB-A> on uhci0
usb0: USB revision 1.0
uhub0: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered
uhci1: <Intel 82801DB (ICH4) USB controller USB-B> port 0xd000-0xd01f at
device 29.1 on pci0
uhci1: [GIANT-LOCKED]
usb1: <Intel 82801DB (ICH4) USB controller USB-B> on uhci1
usb1: USB revision 1.0
uhub1: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub1: 2 ports with 2 removable, self powered
uhci2: <Intel 82801DB (ICH4) USB controller USB-C> port 0xd400-0xd41f at
device 29.2 on pci0
uhci2: [GIANT-LOCKED]
usb2: <Intel 82801DB (ICH4) USB controller USB-C> on uhci2
usb2: USB revision 1.0
uhub2: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub2: 2 ports with 2 removable, self powered
pci0: <serial bus, USB> at device 29.7 (no driver attached)
pcib2: <ACPI PCI-PCI bridge> at device 30.0 on pci0
pci2: <ACPI PCI bus> on pcib2
rl0: <RealTek 8139 10/100BaseTX> port 0xc000-0xc0ff mem
0xdf000000-0xdf0000ff irq 23 at device 12.0 on pci2
miibus0: <MII bus> on rl0
rlphy0: <RealTek internal media interface> on miibus0
rlphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
rl0: Ethernet address: 00:10:dc:ea:72:87
isab0: <PCI-ISA bridge> at device 31.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <Intel ICH4 UDMA100 controller> port
0xf000-0xf00f,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 31.1 on pci0
ata0: channel #0 on atapci0
ata1: channel #1 on atapci0
pci0: <serial bus, SMBus> at device 31.3 (no driver attached)
pci0: <multimedia, audio> at device 31.5 (no driver attached)
fdc0: <floppy drive controller> port 0x3f7,0x3f0-0x3f5 irq 6 drq 2 on acpi0
fdc0: [FAST]


Fatal trap 12: page fault while in kernel mode cpuid = 0; apic id = 00
fault virtual address	= 0x0
fault code		= supervisor read, page not present
instruction pointer	= 0x8:0xc0776a85
stack pointer	        = 0x10:0xc1021b48
frame pointer	        = 0x10:0xc1021b4c
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, def32 1, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 0 (swapper)
trap number		= 12
panic: page fault
cpuid = 0
Uptime: 1s
Shutting down ACPI
Automatic reboot in 15 seconds - press a key on the console to abort
--> Press a key on the console to reboot, or switch off the system now.

I found instructions on how to use the "nm" command to try to resolve
symbols in a non-debug kernel.  Here's what I got from "nm":

%nm kernel | grep c0776a85
%nm kernel | grep c0776a8
%nm kernel | grep c0776a
c0776a20 t fdc_takefirst
c0776aa8 t fdctl_wr
c0776ad8 t fdout_wr
c0776a40 t fdprinttype
c0776a78 t fdsettype

It appears that the instruction pointer might be inside the fdsettype()
function call.

Looking at /usr/src/sys/dev/fdc/fdc.c, I see that fd_probe() calls
fdsettype() before it returns.

BTW, the machine runs 4.10-STABLE w/o problems. Here's what 4.10-STABLE
reports for the floppy drive and controller:

fdc0: <NEC 72065B or clone> at port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on isa0
fdc0: FIFO enabled, 8 bytes threshold
fd0: <2880-KB 3.5" drive (in 1440-KB mode)> on fdc0 drive 0

I'm not sure if there is something strange about this floppy drive, I can't
find anything on the net saying that it is a 2.88MB drive.  I always assumed
the drive was a 1.44MB drive.  The floppy drive's label says it is a
"SFD-321B/LCPN2" model.

I tried an older floppy drive and it gave the same fatal trap error.  Maybe
it is not related to the drive but the controller.

If I disable the floppy drive in the BIOS, the installation CD boots
properly into sysinstall.

Would it be worthwhile to install 5.3-BETA7 on the system and try to build a
debug kernel to see exactly where the fatal trap is occurring?

-john