3
Software/Firmware Description
60
POST error handling
The
Power
On
Self
Test
(POST)
carried
out
by
BIOS
after
startup
examines
the
functionality
of
the
modules
present
on
the
system.
It
reports
any
errors
to
IPMC
in
the
form
of
platform
event
messages.
The
BIOS
continues
the
boot
process
as
long
as
no
errors
are
detected
that
might
be
essential
to
proper
BIOS
operation.
Errors
that
might
affect
BIOS
or
system
operation
can
cause
the
BIOS
to
halt
the
boot
process.
Due
to
the
CPM’s
design
complexity,
the
initialize
time
of
discovered
sub
‐
FRUs
can
vary
significantly
from
product
to
product.
The
BIOS
cannot
predict
sub
‐
FRU
initialization
time,
and
some
boot
devices
could
be
missed
if
allowance
is
not
made
for
this
variable
initialization
time.
A
BIOS
setup
option
allows
user
specification
of
a
sub
‐
FRU
initialization
time
so
the
BIOS
waits
a
specified
amount
of
time
before
it
proceeds
with
the
boot
device
discovery.
Optimization
routines
shorten
the
wait
time
if
all
the
FRUs
are
either
not
installed,
inactive,
or
become
active
before
the
specified
initialization
time
expires.
If
communication
with
the
IPMC
fails,
the
BIOS
unconditionally
waits
for
the
time
configured.
If
any
sub
‐
FRU
is
unable
to
reach
a
required
FRU
state
within
the
time
limit,
the
BIOS
reports
a
system
event
to
the
IPMC.
A
progressive
boot
feature
causes
the
BIOS
to
re
‐
attempt
booting
the
boot
devices
even
if
it
fails.
The
“round
robin
progressive
boot”
causes
the
BIOS
to
attempt
booting
from
the
next
device
in
the
device
list
until
all
boot
order
entries
are
tried.
The
process
repeats
indefinitely
until
a
boot
attempt
succeeds,
or
the
system
is
reset.
Watchdog support
In
addition
to
the
RAS
features
supporting
CPM
boot,
the
following
watchdog
timers
support
the
CPM
in
the
pre
‐
boot
and
OS
runtime
environments:
•
Corrupt
Flash
Detection
(CFD)
watchdog
timer
•
IPMI
Baseboard
Management
Controller
(BMC)
watchdog
timer
The
Corrupt
Flash
Detection
(CFD)
watchdog
timer
is
a
software
‐
based
watchdog
implemented
in
the
IPMC
to
recover
the
system
at
boot
when
the
primary
BIOS
flash
is
either
blank
or
corrupted.
The
IPMC
starts
the
CFD
watchdog
timer
at
payload
reset,
and
it
will
force
a
switch
to
the
secondary
boot
Flash
if
it
is
not
stopped
within
a
specified
time
period.
The
Baseboard
Management
Controller
(BMC)
watchdog
timer
is
a
programmable
watchdog
timer
controlled
by
the
IPMC.
The
BMC
watchdog
timer
triggers
a
configurable
action
(the
default
action
is
reset)
if
some
fault
condition
in
the
system
prevents
a
stop/strobe
of
the
BMC
watchdog.
The
BMC
watchdog
timer
implementation
is
based
on
the
IPMI
specification
and
can
be
configured
or
disabled
by
standard
IPMI
v1.5
commands.
Its
programmable
range
is
from10
ms
to
6,553,600
ms
(6553.5
sec)
in100
ms
(0.1
sec)
intervals.
By
default,
BIOS
enables
the
BMC
watchdog
timer.
The
IPMC
by
default
disables
the
BMC
watchdog
timer
after
a
system
reset.