Use prtconf to find the reason of unexpected reboots

In some cases, "prtconf -vp" can help determine the cause of an unexpected crash/reboot just by knowing what the "reset-reason:" is.

# /usr/sbin/prtconf -pv

System Configuration: Sun Microsystems sun4u

Memory size: 4352 Megabyte

System Peripherals (PROM Nodes):

Node 0xf0029c1c

clock-frequency: 05f5e10

previous-reset-reason: 'POR'

banner-name: '8-slot Sun Enterprise E4500/E5500'

idprom: 01800800.20a0f6d3.00000000.a0f6d3a9.00000000.00000000.00000000.00000000

reset-reason: 'S-POR'

fatal-reset-info: 00006000

breakpoint-trap: 0000007f

#size-cells: 00000002

name: 'SUNW,Ultra-Enterprise'

...

We see that the "reset-reason" is a 'S-POR'. Use the following UltraSPARC(R) II chart to see what might have caused this reset.

reset-reason	Description	Could be caused by
POR	Power On Reset	HW Fatal Reset
S-POR	Soft Power On Reset	Panic, Regular reboot
B-POR	Button Power On Reset	Power-cycle, Power loss
S-XIR	Soft eXternaly Initiated Reset	Watchdog Reset
B-XIR	Button eXternaly Initiated Reset	XIR Button pressed

For the UltraSPARC(R) III systems only the V880 and V480 with OBP 4.10.7+ records the reset-reason. These are the possible codes:

POR Non-specific Trap Type 1

HPOR Sys Power On Normal Power On Reset

APOR Alarm Power On Alarm Power On Reset

(03) Undefined Undefined, should not happen

BPOR Button Reset Hardware "Button" reset

RPOR R/SC Reset RSC/RMC/SC/etc. reset

JPOR JTAG Reset JTAG/Scan-induced reset

WPOR Sys Watchdog System-wide external Watchdog

WDOG CPU Watchdog CPU-specific watchdog reset

XIR External/NMI System/CPU XIR

SIR CPU Instr CPU-specific SIR

ED CPU RED-State CPU-specific RED-State Expection

FATAL Sys Hardware System-wide hardware error/reset

ROMT ROM-Trap ROM Trap -- should not happen

SPOR Software/User General command reset

Note: The system should not have been power cycled or rebooted manually otherwise the "reset-reason" won't correspond to the reason of the unexpected reboot.