Specifications

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.