critical BOOT failure updating to latest 5-Stable (5.4)

[Billy Newsom]

I have a usable kernel that I built from 5-Stable sources on July 4th, 
2005. But the last two days, I tried to compile and install the lastest 
5-Stable, and neither one would boot.

During the boot, the entire normal dmesg is output (the part which is in 
"bold" on the CRT), except the last line which normally says,
	Mounting root from ufs:/dev/ad0s1a
the system freezes with the disk LED "on" on the computer.

So the last message I see on the screen during the failed boot is this:
SMP: AP CPU #1 Launched!
<Freeze>

Okay, since I tried two kernels, and both froze up at the same place, 
but there was one minor difference, here it is... I saw this error the 
very last time I booted to the second bad kernel:

ad0: TIMEOUT - READ_DMA retrying (2 retries left) LBA=0

This error was right below the line
SMP: AP CPU #1 Launched!

Okay, that is definitely an indication of some sort of timing or driver 
issue. But as far as I know, this hard disk has no other known problems, 
and obviously it boots flawlessly on the other 5.4 kernels and has for a 
long, long time. Has anything changed in the bootstrap code for the last 
two months in 5-Stable?

I have not left the machine frozen for more than a couple of minutes, 
but during that time Scroll Lock/Scroll Back won't work. But it's 
possible the system is possibly in a long (but finite) state of disk 
reading and it's not completely frozen.

I am inclusing the dmesg from a good boot. It looks like the bad boot 
messages are the same, at least as far as I can tell.


Copyright (c) 1992-2005 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 5.4-STABLE #0: Mon Jul  4 18:28:47 CDT 2005
     root at me.me.me:/usr/obj/usr/src/sys/BILLYSMP3
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Pentium Pro (199.31-MHz 686-class CPU)
   Origin = "GenuineIntel"  Id = 0x617  Stepping = 7
 
Features=0xfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV>
real memory  = 536870912 (512 MB)
avail memory = 515719168 (491 MB)
MPTable: <IBM-PCCO CrossFire MP>
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
  cpu0 (BSP): APIC ID:  1
  cpu1 (AP): APIC ID:  0
ioapic0: Assuming intbase of 0
ioapic0 <Version 1.1> irqs 0-23 on motherboard
npx0: <math processor> on motherboard
npx0: INT 16 interface
cpu0 on motherboard
cpu1 on motherboard
pcib0: <MPTable Host-PCI bridge> pcibus 0 on motherboard
pci0: <PCI bus> on pcib0
isab0: <PCI-ISA bridge> at device 1.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <Intel PIIX3 WDMA2 controller> port 
0xfff0-0xffff,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 1.1 on pci0
ata0: channel #0 on atapci0
ata1: channel #1 on atapci0
uhci0: <Intel 82371SB (PIIX3) USB controller> port 0x5400-0x541f irq 19 
at device 1.2 on pci0
usb0: <Intel 82371SB (PIIX3) USB controller> 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
rl0: <D-Link DFE-530TX+ 10/100BaseTX> port 0x5000-0x50ff mem 
0x50000000-0x500000ff irq 18 at device 6.0 on pci0
miibus0: <MII bus> on rl0
rlphy0: <RealTek internal media interface> on miibus0
rlphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
rl0: Ethernet address: 00:50:ba:4d:57:6f
pci0: <display, VGA> at device 11.0 (no driver attached)
orm0: <ISA Option ROM> at iomem 0xc0000-0xc7fff on isa0
fdc0: <Enhanced floppy controller> at port 0x3f0-0x3f5 irq 6 drq 2 on isa0
fd0: <1440-KB 3.5" drive> on fdc0 drive 0
atkbdc0: <Keyboard controller (i8042)> at port 0x64,0x60 on isa0
atkbd0: <AT Keyboard> irq 1 on atkbdc0
kbd0 at atkbd0
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <6 virtual consoles, flags=0x300>
sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0
sio0: type 16550A
sio1 at port 0x2f8-0x2ff irq 3 on isa0
sio1: type 16550A
ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0
ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode
ppc0: FIFO with 16/16/8 bytes threshold
ppbus0: <Parallel port bus> on ppc0
lpt0: <Printer> on ppbus0
lpt0: Interrupt-driven port
ppi0: <Parallel I/O> on ppbus0
ep0: <3Com 3C509B-TPO EtherLink III (PnP)> at port 0x210-0x21f irq 5 on isa0
ep0: Ethernet address: 00:a0:26:77:23:83
unknown: <PNP0303> can't assign resources (port)
unknown: <PNP0700> can't assign resources (port)
unknown: <PNP0501> can't assign resources (port)
unknown: <PNP0401> can't assign resources (port)
unknown: <IBM37a0> can't assign resources (port)
Timecounters tick every 10.000 msec
IP Filter: v3.4.35 initialized.  Default = pass all, Logging = enabled
Interrupt storm detected on "irq5: ep0"; throttling interrupt source
ad0: 8809MB <QUANTUM FIREBALLP KA9.1/A42.0400> [17898/16/63] at 
ata0-master WDMA2
ad2: 2014MB <WDC AC22100H/10.07H11> [4092/16/63] at ata1-master WDMA2
acd0: DVDROM <TOSHIBA DVD-ROM SD-M1212/1R14> at ata1-slave PIO4
SMP: AP CPU #1 Launched!
Mounting root from ufs:/dev/ad0s1a