Bug 144045

Booting with ACPI enabled in BIOS on Norco-7732 motherboard based box which
designed for network appliances (http://www.norcotek.com/NORCO-7732V.php)
leads to that:

kernel trap 12 with interrupts disabled


Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0xf000e2c3
fault code              = supervisor read, page not present
instruction poRoot mount waiting for: usbus2 usbus1 usbus0
uhub0: 2 ports with 2 removable, self powered
uhub1: 2 ports with 2 removable, self powered
inter   = 0x20:0xc0509799
stack pointer           = 0x28:0xc2f71c9c
frame pointer           = 0x28:0xc2f71cc0
code segment            = base rx0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = resume, IOPL = 0
current process         = 10 (idle)
[thread pid 10 tid 64003 ]
Stopped at      acpi_battery_get_battinfo+0x2859:       movzbl  0(%ebx),%eax
db>

Fix: 

Disabling ACPI avoids the trap. Here is the output of bt:

db> bt
Tracing pid 10 tid 64003 td 0xc3036b90
acpi_battery_get_battinfo(c2e71cd4,c0abc632,1,c2e71cf4,c086174f,...) at acpi_battery_get_battinfo+0x2859
set_fpregs(1,c2e71cf4,c086174f,1,0,...) at set_fpregs+0x11b
cpu_idle(1,0,c3036b90,c2e71cf4,0,...) at cpu_idle+0x12
sched_idletd(0,c2e71d38,0,0,0,...) at sched_idletd+0x6f
fork_exit(c08616e0,0,c2e71d38) at fork_exit+0x90
fork_trampoline() at fork_trampoline+0x8
--- trap 0, eip = 0, esp = 0xc2e71d70, ebp = 0 ---
db>
How-To-Repeat: Enable ACPI in BIOS and try to boot.