WhatisaBLOCK?Ablockisthesmallestlogicallyaddressableunitofdatathataspecifieddevicecantransferinaninput/outputoperation.ForXBOX360sthatiseither16KBor132KB.WhatisaBADBLOCK?BadBlocksareblocksthatcontainoneormoreinvalidbitswhosereliabilityisnotguaranteed.BadBlocksmaybepresentwhenthedeviceisshipped,ormaydevelopduringthelifetimeofthedevice.HowtodetermineBADBLOCKS?InoneblocktherearenPages,allhaveafixedsizeof528Bytes(nomatteriftheBlockis16Kor128K).EveryPagehas16BytebigECCdataatitsend.TheblockitselfdoesnothaveECCdata,onlythepageshave!Intheorythewholeblockgetsfilledwithzerosifitsbad,practiclyit'snotlikethat.So,ifthefirst12Bytesofthepage'sECCdataisnulled,thepageismarkedbad,sothewholeblockisaswell.Theremaining4BytesoftheECCistheCRCData.Ifthefirst12BytesofECCis0xFFthepagehasnodata(empty,butNOTfaulty)andifitholdanythingelsethan0x00or0xFFthenthepageisfilledwithdata.WhathappenswhenaBADBLOCKdevelops?Therearetwomethodstoreplacetheblock.1.SkipBlockMethod2.ReserveBlockMethodHowdoestheReserveBlockMethodwork?Blocksarenotskippedbutrathertheyarere-directedtoaReservedBlockAreausedspecificallyforBadBlockreplacement.TheReservedBlockAreaalsostores/savestheBadBlockTablethatkeepstrackofthere-mapped“developedBadBlocks”.WhichmethoddoestheXBOXemploy?Shortanswerboth.In16MBnandstheXBOXexclusivelyusestheReserveBlockMethod,whilein256MBor512MBnandsitusesboth.TheMUareaofthenandusestheSkipBlockMethod,whiletheareawherethedashandkernelarestoredusestheReserveBlockMethod.16MBNANDBlocksizeRAW:18896Bytes16.5KBEladblockBadblock色Etadblock?Badblock電116MBNANDBlocksizeRAW:18896Bytes16.5KBEladblockBadblock色Etadblock?Badblock電1FirrtBloclc*t992-LastBlack:#1024-Reser^'edBadBlockArea0x20(32Blocks)JL|,B^dhlack&adblMkBadblock0adhlock 0x160R.EEervEdforData|R.EEervEdforData|Dash.KerneL-.?)IfyounoticedinthememorytableaboveanyBadblocksencounteredareconsecutivelymovedtotheReservedBadBlockArea.ThefirstBadBlock(0x168)ismovedtoBlock0x3FFinthereservedarea,thenext(0x1F6)ismovedto0X3FE,anditcontinuesuntilallBadBlockshavebeenremapped.WhenIreadmynandIhaveBadblockswhereisthatdatastored?WhenreadingyournandanyBadblockswouldhavealreadybeenremappedtothereservearea.Thisisimportanttokeepinmind,specificallywhenyouencounterBadblockswherecrucialdataiskeptsuchasblocks0x001(KeyVault),0x3DE(FirstConfigBlock),and0x3DF(SecondConfigBlock).HowwouldIremaptheBadBlocksinthediagramwithnandpro?AssumingyourattemptingtoflashthelatestreleaseofXBRebootnamedas‘xbr.bin'.Andhavemadeafull-backupandhavealreadyinjectedyourKeyVaultandConfigurationBlocksinto‘xbr.bin'.Thecommandswouldbeasfollow:nandproxbr.bin:-r16nandproxbr.bin:-w16nandproxbr.bin:-r16nandproxbr.bin:-w16nandproxbr.bin:-r16nandproxbr.bin:-w16nandproxbr.bin:-r16nandproxbr.bin:-w16badblock168.binnandproxbr.bin:-r16nandproxbr.bin:-w16nandproxbr.bin:-r16nandproxbr.bin:-w16nandproxbr.bin:-r16nandproxbr.bin:-w16nandproxbr.bin:-r16nandproxbr.bin:-w16badblock168.bin1681badblock168.bin3FF1badblock1F6.bin1F61badblock1F6.bin3FE1badblock23A.bin23A1badblock23A.bin3FD1badblock308.bin3081badblock308.bin3FC1IfusingXeLLoustoflashdoIneedtoremapBadblocks?AccordingtotheXeLLousreleasenotesno,itissupposetobeoneofthemainfeaturesoftheupdate.Thatisnottosaybugsmightnotbeencountered.Ifyouencountersuspiciousissues,andbelieveitmightberelatedtoabadflash,thenIrecommendflashingmanuallywithnandproorusingtrancy'sXBR-FlashforLinux.IhaveaBadblockbetweenblocks0x000and0x050,andcan'tbootintoXell(free60version).Firstofallensureyourusingthefree60versionofXell.NextyouwillneedtobackupthelocationoftheremappedBadBlockslikeso(RemeberyourfirstBadblockalwaysgoesto3FF,andeachfollowingBadblockgetsremappedasillustratedinthediagram):nandprolpt:-r16backup3FF.bin3FF1AssumingyourfirstBadblockwasat0x010,youwillneedtoremapthefree60Xelldatathatwasintendedtobestoredinthatblock.Likethis.nandproxell.bin:-r16xell10.bin101nandprolpt:-w16xell10.bin3FF1Lastlythebadblockneedstoerasedtopreventanycorruption:nandprolpt:-e16101XBOX256/512MBNANDBLOCKManagementRAW:276824064Byte.5(RAW:264ME.256ME)LastElock:#2048RAW:553648128Byte.5(RAW:52BME.512ME)LastERAW:276824064Byte.5(RAW:264ME.256ME)LastElock:#2048RAW:553648128Byte.5(RAW:52BME.512ME)LastElock:#4096256/512MBNANDBlocksizeRAW:13516BBytes1S2KBRAW:69206015Byte^=66MBLastBlock:*t4095=0x1000u.5ing16KBBlocksize.Badblock@3x0F3BadblockReservedforDataReservedBadBlockArea(DashTKernel...)0x20{32Blocks)ReservedforMemoryUnit(NoBadBlockArea)BadBlock-HandlinE：SkipBlockBadblock@3x403E日dblock@Badblock@珈CiCiOx'OFBUnderstanding256/512MBmemorymapandNandpro'stranslation:Theblocksizein256/512Nandsis132KB(135168Bytes).ThisisalittledifferentthenhowNandproreferencesandaddressesblocks.NomattertheBlocksizeofyournandnandprousesablocksizeof16KBthatmeansthatforeveryBadblockinthe256/512MBnandprowillreport8consecutiveerrors.IfyounoticedinthememorytableaboveanyBadblocksencounteredareconsecutivelymovedtotheReservedBadBlockArea.ThefirstBadblock(0x0F8)ismovedtoBlock0xFF8(16KB)orBlock0x1FF(132KB)inthereservedarea,anyconsecutiveBadblockswouldofbeenmovedtoblocks0xFF0(16KB)orBlock0x1FE(132KB)andsoforth.WhenIreadmynandIhaveBadblockswhereisthatdatastored?WhenreadingyournandanyBadblockswouldhavealreadybeenremappedtothereservearea.Thisisimportanttokeepinmind,specificallywhenyouencounterBadblockswherecrucialdataiskeptsuchasblocks0x001(KeyVault),0xEF7(ConfigBlock),.HowwouldIremaptheBadBlocksinthediagramwithnandpro?AssumingyourattemptingtoflashthelatestreleaseofXBRebootnamedas‘xbr.bin'.Andhavemadeafull-backupandhavealreadyinjectedyourKeyVaultandConfigurationBlocksinto‘xbr.bin'.Thecommandswouldbeasfollow:nandproxbr.bin:-r16badblockF8.binF88nandproxbr.bin:-w16badblockF8.binFF88Is8correct?Yesremembernandproreferenceblocksinsizesof16KB,but256/512MBhaveablocksizeof132KB.132/16isequalto8,thatwhyyouneedtouse8.IfusingXeLLoustoflashdoIneedtoremapBadblocks?AccordingtotheXeLLousreleasenotesno,itissupposetobeoneofthemainfeaturesoftheupdate.Thatisnottosaybugsmightnotbeencountered.Ifyouencountersuspiciousissues,andbelieveitmightberelatedtoabadflash,the