bootloader代码分析报告

1、Bootloader代码分析报告徐 凯2007-8-3TOC o 1-3 h z u HYPERLINK l _Toc173943360 Bootloaader代码码分析报告 PAGEREF _Toc173943360 h 1 HYPERLINK l _Toc173943361 1.启动代码码分析 PAGEREF _Toc173943361 h 1 HYPERLINK l _Toc173943362 1.1.veector.s代码分析析 PAGEREF _Toc173943362 h 1 HYPERLINK l _Toc173943363 1.1.1.宏定义 PAGEREF _Toc17394

2、3363 h 5 HYPERLINK l _Toc173943364 1.1.3.判断是否是是thumbb指令 PAGEREF _Toc173943364 h 6 HYPERLINK l _Toc173943365 1.1.4.定义新程序序、引入新符符号 PAGEREF _Toc173943365 h 6 HYPERLINK l _Toc173943366 1.1.5.定义新程序序、引入新符符号 PAGEREF _Toc173943366 h 7 HYPERLINK l _Toc173943367 1.1.6.定义系统异异常向量表 PAGEREF _Toc173943367 h 7 HYPER

3、LINK l _Toc173943368 1.1.7.程序跳转宏宏定义 PAGEREF _Toc173943368 h 7 HYPERLINK l _Toc173943369 1.1.8.异常处理程程序定义 PAGEREF _Toc173943369 h 7 HYPERLINK l _Toc173943370 1.1.9.声明C主函数程序序入口 PAGEREF _Toc173943370 h 10 HYPERLINK l _Toc173943371 1.1.10.定义vecttor.s中中需要用到的的连接器变量量 PAGEREF _Toc173943371 h 10 HYPERLINK l _

4、Toc173943372 1.1.11.定义从FLAASH启动程程序的函数 PAGEREF _Toc173943372 h 11 HYPERLINK l _Toc173943373 1.2.syysinitt.s代码分分析 PAGEREF _Toc173943373 h 11 HYPERLINK l _Toc173943374 1.2.1.引入S3C45110相关系统统配置寄存器器的地址 PAGEREF _Toc173943374 h 18 HYPERLINK l _Toc173943375 1.2.2.定义用于配配置ROM和RAM的宏 PAGEREF _Toc173943375 h 18 H

5、YPERLINK l _Toc173943376 1.2.3.定义用于配配置SYSCCFG的宏 PAGEREF _Toc173943376 h 18 HYPERLINK l _Toc173943377 11.2.4.定义用于初初始化内存的的函数IniitMemoory PAGEREF _Toc173943377 h 18 HYPERLINK l _Toc173943378 1.2.5.定义用于初初始化内存的的函数IniitMemoory PAGEREF _Toc173943378 h 20 HYPERLINK l _Toc173943379 1.2.6.定义内存重重设置函数RResetMMem

6、Sett PAGEREF _Toc173943379 h 21 HYPERLINK l _Toc173943380 1.2.7.初始化21种中断源源响应函数IInitInnterruupt PAGEREF _Toc173943380 h 21 HYPERLINK l _Toc173943381 1.2.8.初始化18个外部I/OO端口函数InnitPorrt PAGEREF _Toc173943381 h 21 HYPERLINK l _Toc173943382 1.2.9.初始化2个计时器的的函数IniitTimeer PAGEREF _Toc173943382 h 22 HYPERLINK

7、 l _Toc173943383 1.2.10.初始化2个串口函数数InitUUart PAGEREF _Toc173943383 h 22 HYPERLINK l _Toc173943384 1.2.11.初始化栈函函数InittStackk PAGEREF _Toc173943384 h 23 HYPERLINK l _Toc173943385 1.2.12.系统初始化化函数IniitSysttem PAGEREF _Toc173943385 h 24 PAGE 48启动代码分析vector.s代码分析析由于连接器参数数中有-fiirst vvectorr.o，所以以先从这个文文件开始分析

8、析。首先，列列出源代码：ModeMassk EQU0 x1FSVC32MoodeEQU0 x13IRQ32MoodeEQU0 x12FIQ32MoodeEQU0 x11User32MModeEQU0 x10Abort322ModeEQU0 x17Undef322ModeEQU0 x1BIRQ_BITTEQU0 x80FIQ_BITTEQU0 x40;RomBasseAddrrEQU0RamBaseeAddrEQU&100;RamEnddAddr EQQU&200GBLSMaainEnttryMainEnttrySETSmainnIMPORT$MainnEntryy;*;鯡tassm.exee默

9、GBLL THUMMBCODEE CONFFIG = 16THUMBCOODE SEETLTRUEECODE32| THUMBCOODE SEETLFALSSE THUMBBCODECODE32 ;foor staart-upp codee for Thumbb modee ;*AREASeelfBooot,CODE,READOONLYIMPORTUDF_IINS_VEECTORIMPORTSWI_SSVC_VEECTORIMPORTINS_AABT_VEECTORIMPORTDAT_AABT_VEECTORIMPORTIRQ_SSVC_VEECTORIMPORTFIQ_SSVC_VEECTO

10、RENTRYIF :DEFF: |adds$verrsion|ELSEEXPORT_maiin_mainENDIFResetEnntrybSYS_RRST_HAANDLERRbUDF_IINS_HAANDLERRbSWI_SSVC_HAANDLERRbINS_AABT_HAANDLERRbDAT_AABT_HAANDLERRb.bIRQ_SSVC_HAANDLERRbFIQ_SSVC_HAANDLERR;*MACRO$LabelHANDLLER$Vecttor$Labelsublr, lr, #4stmfdssp!, r0-r33, lrldrr0, =$Veectorldrpc, r0ldm

11、fdssp!, r0-r33, pcMENDUDF_INSS_HANDDLERstmfdssp!, r0-r33, lrldrr0, =UDFF_INS_VECTOORmovlr, pcldrpc, r0ldmfdssp!, r0-r33, pcSWI_SVCC_HANDDLERstmfdssp!, r0-r33, lrldrr0, =SWII_SVC_VECTOORmovlr, pcldrpc, r0ldmfdssp!, r0-r33, pcINS_ABTT_HANDDLERsublr, lr, #4stmfdssp!, r0-r33, lrldrr0, =INSS_ABT_VECTOORm

12、ovlr, pcldrpc, r0ldmfdssp!, r0-r33, pcDAT_ABTT_HANDDLERsublr, lr, #4stmfdssp!, r0-r33, lrldrr0, =DATT_ABT_VECTOORmovlr, pcldrpc, r0ldmfdssp!, r0-r33, pcIRQ_SVCC_HANDDLERsublr, lr, #4stmfdssp!, r0-r112, lrrmrsr0, spsrrstmfdssp!, r0ldrr0, =IRQQ_SVC_VECTOORldrpc, r0FIQ_SVCC_HANDDLERsublr, lr, #4stmfdss

13、p!, r0-r112, lrrmrsr0, spsrrstmfdssp!, r0ldrr0, =IRQQ_SVC_VECTOORldrpc, r0;*SYS_RSTT_HANDDLERmrsr0, cpsrr;enteer svcc modee and disabble irrq,fiqqbicr0, r0, #ModeeMaskorrr0, r0, #(SVCC32Modde :ORR: IRQQ_BIT :OR: FIQ_BBIT)msrcpssr_c, r0IMPORTInitSSystemmblInittSysteemadrr0, ReseetEntrrymovr3, #(RaamB

14、aseeAddr16)ldrr1, BaseeOfROMMldrr2, TopOOfROMaddr1, r1, r3addr2, r2, r30ldmiarr0!, r4-r111stmiarr1!, r4-r111cmpr1, r2bcc%B00subr1, r1, r2subr0, r0, r1ldrr1, BaseeOfBSSSldrr2, BaseeOfZerroaddr1, r1, r3addr2, r2, r31cmpr1,r2ldrccrr4, rr0, #4strccrr4, rr1, #4bcc%B11movr0,#0ldrr2,EndOffBSSaddr2, r2, r33

15、cmpr1,r2strccrr0, rr1, #4bcc%B33IMPORTRemappMemorryadrr0, ReseetEntrryldrr1, =RemmapMemmoryldrr2, BaseeOfROMMsubr2, r1, r2addr0, r0, r2addr1, r2, r3movr2,#320ldrr3, r0, #4strr3, r1, #4subsr22, r2,#1bne%B00ldrlr,GotoMMain bRemappMemorry GotoMaiinDCD$MainnEntryy;*IMPORT|Imagge$ROO$Basse|; ROMM codee s

16、tarrtIMPORT|Imagge$ROO$Limmit|; RAMM dataa starrts affter RROM prrogrammIMPORT|Imagge$RWW$Basse|; Pree-inittialissed vaariabllesIMPORT|Imagge$ZII$Basse|; uniinitiaalisedd variiablessIMPORT|Imagge$ZII$Limmit|; Endd of vvariabble RAAM spaaceBaseOfRROMDCD|Imagge$ROO$Basse|TopOfROOMDCD|Imagge$ROO$Limmit

17、|BaseOfBBSSDCD|Imagge$RWW$Basse|BaseOfZZeroDCD|Imagge$ZII$Basse|EndOfBSSSDCD|Imagge$ZII$Limmit|;*TIP_SIZZEEQU256IMPORTResettMemSeetEXPORTtranss_to_bboottrans_tto_boootmovlr, r1; a2 = r1ldrr1, =RessetMemmSetldrr2, BaseeOfROMMsubr2, r1, r2addr0, r0, r2; a1 = r0movr2,#TIP_SIZE0ldrr3, r1, #4strr3, r0, #

18、4subsr22, r2,#1bne%B00subr0, r0, #TIP_SIZE*4movpc,r0;*END宏定义1ModeMMask EQU0 x1F2SVC322ModeEQU0 x133IRQ322ModeEQU0 x124FIQ322ModeEQU0 x115User332ModeeEQU0 x106Abortt32ModdeEQU0 x177Undeff32ModdeEQU0 x1B8IRQ_BBITEQU0 x809FIQ_BBITEQU0 x4010;RommBaseAAddrEQU011RamBBaseAdddrEQU&10012;RammEndAdddr EEQU&20

19、0行1定义了CPPSR中表示示模式位的55位。行2-7定义了了6种处理器器模式（除ssystemm模式）对应应的CPSRR位。行8-7定义了了CPSR中中FIQ与IIRQ置位。行10、12为为注释，行111定义了一一个宏，&的意义等等于DCD伪伪指令，其分分配一个字的的内存，并用用100初始始化该字的内内存，并使用用RomBaaseAdddr标志这段段内存的实际际地址。宏定义13GBLSSMainEEntry14MainnEntryySETSmainn15IMPOORT$MainnEntryy行13-15声声明了一个字字符串变量MMainEnntry,并并将其设置为为”main”，并引入外外部

20、符号”main”。判断是否是thhumb指令令18GBLLL TTHUMBCCODE19 CCONFIGG = 11620THUMMBCODEE SETLLTRUEE21CODEE3222| 23THUMMBCODEE SETLLFALSSE242526 THHUMBCOODE27CODEE32 ;for startt-up ccode ffor Thhumb mmode28 行18声明了逻逻辑变量THHUMBCOODE行19-24执执行了一个IIF ELSSE ENDDIF指令，CONFIG变量是 REF _Ref173902364 n h 1中第88页说明的汇编器域定义变量，如果其为32则

21、说明本文件采用ARM汇编器，相应地把THUMBCODE设置为FALSE，若为16则是使用thumb汇编器，相应地把THUMBCODE设置为TRUE。行26-28，强制执行32位的ARM指令，感觉很奇怪，应该是用CODE16命令才对。定义新程序、引引入新符号31AREAASelfBBoot,CODE,READOONLY3233IMPOORTUDF_IINS_VEECTOR34IMPOORTSWI_SSVC_VEECTOR35IMPOORTINS_AABT_VEECTOR36IMPOORTDAT_AABT_VEECTOR37IMPOORTIRQ_SSVC_VEECTOR38IMPOORTFIQ_S

22、SVC_VEECTOR行31定义了一一个新的程序序段SelffBoot。行33-38引引入了一系列列的符号，这这些符号在sysinnit.s中中定义并导出出。定义新程序、引引入新符号40ENTRRY41IF :DEF: |ads$versiion|42ELSEE43EXPOORT_maiin44_maain45ENDIIF行40首先声明明了程序的入入口根据 REF _Ref173902364 n h 1中第第89页的说说明，行411-45判断断程序是给AADS还是SSDT执行的的，如果是如果果是SDT，则则导出_mmain符号号，并开始定定义_maain函数的的开始。定义系统异常向向量表46R

23、eseetEntrry47bSYYS_RSTT_HANDDLER48bUDDF_INSS_HANDDLER49bSWWI_SVCC_HANDDLER50bINNS_ABTT_HANDDLER51bDAAT_ABTT_HANDDLER52b.53bIRRQ_SVCC_HANDDLER54bFIIQ_SVCC_HANDDLER行46-54定定义了系统异异常处理向量量表，并在vvectorr.o首次执执行时首先执执行行47的的代码。程序跳转宏定义义57MACRRO58$LabbelHANDLLER$Vecttor59$Labbel60sublr, llr, #4461stmffdsp!, r0-rr

24、3, lrr62ldrr0, =$Vecttor63ldrpc, r064ldmffdsp!, r0-rr3, pcc65MENDD行57-65定定义了一个有有1个参数的的宏HANDDLER，该该宏实现程序序跳转，跳转转到$Vecctor所指指向内存所保保存的内存地地址的值，执执行完该函数数后，恢复现现场，并返回回原来的状态态。异常处理程序定定义67UDF_INS_HHANDLEER68stmffdsp!, r0-rr3, lrr69ldrr0, =UDF_IINS_VEECTOR70movlr, ppc71ldrpc, r072ldmffdsp!, r0-rr3, pcc73SWI_SVC_

25、HHANDLEER74stmffdsp!, r0-rr3, lrr75ldrr0, =SWI_SSVC_VEECTOR76movlr, ppc77ldrpc, r078ldmffdsp!, r0-rr3, pcc79INS_ABT_HHANDLEER80sublr, llr, #4481stmffdsp!, r0-rr3, lrr82ldrr0, =INS_AABT_VEECTOR83movlr, ppc84ldrpc, r085ldmffdsp!, r0-rr3, pcc86DAT_ABT_HHANDLEER87sublr, llr, #4488stmffdsp!, r0-rr3, lrr8

26、9ldrr0, =DAT_AABT_VEECTOR90movlr, ppc91ldrpc, r092ldmffdsp!, r0-rr3, pcc93IRQ_SVC_HHANDLEER94sublr, llr, #4495stmffdsp!, r0-rr12, llr96mrsr0, sspsr97stmffdsp!, r098ldrr0, =IRQ_SSVC_VEECTOR99ldrpc, r0100FIQQ_SVC_HANDLLER101subblr, llr, #44102stmmfdsp!, r0-rr12, llr103mrssr0, sspsr104stmmfdsp!, r0105l

27、drrr0, =IRQ_SSVC_VEECTOR106ldrrpc, r0107108;*109SYSS_RST_HANDLLER110mrssr0, ccpsr;enteer svcc modee and disabble irrq,fiqq111biccr0, rr0, #MModeMaask112orrrr0, rr0, #(SVC322Mode :OR: IRQ_BBIT :OOR: FIIQ_BITT)113msrrcpsr_c, r00114115IMPPORTInitSSystemm116blInitSSystemm117118adrrr0, RResetEEntry119mov

28、vr3, #(RamBBaseAdddr116)120ldrrr1, BBaseOffROM121ldrrr2, TTopOfRROM122adddr1, rr1, r33123adddr2, rr2, r331240125ldmmiar0!, r4-rr11126stmmiar1!, r4-rr11127cmppr1, rr2128bccc%B0129130subbr1, rr1, r22131subbr0, rr0, r11132ldrrr1, BBaseOffBSS133ldrrr2, BBaseOffZero134adddr1, rr1, r33135adddr2, rr2, r331

29、361137cmppr1,r2138ldrrccr4, r0, #4139strrccr4, r1, #4140bccc%B1141142movvr0,#0143ldrrr2,EndOffBSS144adddr2, rr2, r331453146cmppr1,r2147strrccr0, r1, #4148bccc%B3149150IMPPORTRemappMemorry151152adrrr0, RResetEEntry153ldrrr1, =RemappMemorry154ldrrr2, BBaseOffROM155subbr2, rr1, r22156adddr0, rr0, r2215

30、7adddr1, rr2, r33158movvr2,#321590160ldrrr3, r0, #4161strrr3, r1, #4162subbsr2, rr2,#1163bnee%B0164165ldrrlr,GotoMMain 166bRRemapMMemoryy 行67-1666定义了7种种模式异常的的处理函数具体地：UDF_INSS_HANDDLER 执行UDF_INS_VVECTORR内存所保存存的指令后，返返回到异常发发生之前的状状态。类似，SWI_SVCC_HANDDLER, INS_ABTT_HANDDLER, DAT_ABTT_HANDDLER, IRQ_SVCC_HA

31、NDDLER, FIQ_SVCC_HANDDLER也执执行类似的操操作，执行XXX_XX_VECTOOR内存所保保存的指令，然然后返回到异异常发生之前前的状态。SYS_RSTT_HANDDLER异常常处理程序与与其它异常处处理程序有很很大不同，行110-1113使得处理理器进入SVVC模式，并并且禁止FIIQ与IRQQ。行115-1116使得程序序跳转到syysinitt.s中定义义的InittSysteem函数中执执行，并在执执行结束后返返回。IniitSysttem函数的的作用是进行行内存、堆栈栈、LED端端口、串口、定定时器以及中中断的初始化化工作，具体体讲解请参见见sysinnit.s

32、中中的分析（ REF _Ref173943344 n h 1.2.112）。行118将异常常向量表ReesetEnntry的地地址保存入rr0。行119-1228将boootloadder的ROO段拷贝入内内存。行130-1440将boootloadder的RWW段拷贝入内存存。行142-1448将内存中中的ZI段初初始化为0。行150-1663将RemmapMemmory函数数拷贝入内存存中。行165将返回回地址进行设设置。行166执行RRemapMMemoryy函数（在syysinitt.s中定义义），RemappMemorry函数主要要是设置ROOMCON00、ROMCCON1和DRAM

33、CCON0、DRAMCCON1；并并将IRQ_SERVIICE函数的的地址存入一一个内存中的的数组中。RemapMeemory函函数执行完后后将跳入biios.c中中定义的maain函数。声明C主函数程程序入口168GottoMainnDCD$MainnEntryy行168声明了了GotoMMain标号号，其被定义义为变量$MaiinEntrry的值“main”定义vectoor.s中需需要用到的连连接器变量根据文献 REF _Ref173919864 n h 2第56-557页中的说说明，行1770-1811引入了由连连接器预定义义的变量值。170;*171IMPPORT|Imagge$RO

34、O$Basse|; ROMM codee starrt172IMPPORT|Imagge$ROO$Limmit|; RAMM dataa starrts affter RROM prrogramm173IMPPORT|Imagge$RWW$Basse|; Pree-inittialissed vaariablles174IMPPORT|Imagge$ZII$Basse|; uniinitiaalisedd variiabless175IMPPORT|Imagge$ZII$Limmit|; Endd of vvariabble RAAM spaace176177BasseOfROOMDCD|Im

35、agge$ROO$Basse|178ToppOfROMMDCD|Imagge$ROO$Limmit|179BasseOfBSSSDCD|Imagge$RWW$Basse|180BasseOfZeeroDCD|Imagge$ZII$Basse|181EnddOfBSSSDCD|Imagge$ZII$Limmit|定义从FLASSH启动程序序的函数184TIPP_SIZEEEQU256185186IMPPORTResettMemSeet187EXPPORTtranss_to_bboot188traans_too_boott189movvlr, rr1; a2 = r1190ldrrr1, =Res

36、ettMemSeet191ldrrr2, BBaseOffROM192subbr2, rr1, r22193adddr0, rr0, r22; a1 = r0194movvr2,#TIP_SIZE1950196ldrrr3, r1, #4197strrr3, r0, #4198subbsr2, rr2,#1199bnee%B0200201subbr0, rr0, #TTIP_SIIZE*4202movvpc,r0行184-2002定义了从从FLASHH固定地址BBIOS_LLOAD00 x10000启动程序的的函数，似乎乎是重新启动动的程序。sysinitt.s代码分分析首先列出syssini

37、t.s的源代码码INCLUDEEs3c45100.sRomBaseeAddrEQU0RomEndAAddrEQU&20RamBaseeAddrEQU&100RamEndAAddrEQU&200AREAteext, CCODE, READOONLYSFR_BASSEEQU0 x3fff;0 x3fff00000SRAM_BAASEEQU0 x3f8;0 x3f800000;EXPORTTInitMMemoryyInitMemmoryldrr0, =SYSSCFGldrr1, =SDRRAM_ITTF :ORR: SFRR_BASEE16 :OR: SRAM_BASE6 :OOR: CAACHE_

38、AALL :OOR: CAACHE_EENstrr1, r0ldrr0, =CLKKCONldrr1, =0strr1, r0ldrr0, =EXTTACON00ldrr1, =0 x00fff0ffffstrr1, r0ldrr0, =EXTTACON11ldrr1, =0 x00fff0ffffstrr1, r0ldrr0, =EXTTDBWTHHldrr1, =0 xfffff5556str r1, r0adrr0, MemCCfgParraldmiarr0, rr1-r111ldrr0, =ROMMCON0stmiarr0, rr1-r111movpc, r14MemCfgPParaD

39、CDRommBaseAAddr10 :OOR RommEndAdddr220 :ORR: &600;&1088400600DCD&1008420660DCD&1008420660DCD&1008420660DCD&1008420660DCD&1008420660DCDRammBaseAAddr10 :OOR: RaamEndAAddr20 :OOR: &3398;&1000003988DCD&1000403998DCD&1000403998DCD&1000403998DCD&cee2983ffd EXPORTRemappMemorryRemapMeemoryadrr0, RemaapMemPP

40、araldmiarr0, rr1-r111ldrr0, =ROMMCON0stmiarr0, rr1-r111nopnopldrr0, =IRQQ_SVC_VECTOORldrr1, =IRQQ_SERVVICE;IRQ_SVC_VVECTORR in rram, sso sett it aafter remappstr r1, r0movpc, r14RemapMeemParaaDCD&1220400660DCD&1008420660DCD&1008420660DCD&1008420660DCD&1008420660DCD&1008420660DCD&1000003998DCD&100040

41、3998DCD&1000403998DCD&1000403998DCD&cee2983ffdEXPORTResettMemSeetResetMeemSetadrr0, ReseetMemPParaldmiarr0, rr1-r111ldr r0, =ROMMCON0stmiarr0, rr1-r111nopnopmovpc, r14ResetMeemParaaDCD&2000000660DCD&0000000660DCD&0000000660DCD&0000000660DCD&0000000660DCD&0000000660DCD&0000000000DCD&0000000000DCD&000

42、0000000DCD&0000000000DCD&0000083ffd;*InitIntterrupptldrr0, =INTTMSKldrr1, =0 x33ffffffstrr1, r0;disaable aall innterruuptmovpc,r14;*InitPorrtldrr0, =IOPPMODldrr1, =1strr1, r0;all inputt but p0 ouutputldrr0, =IOPPCONldrr1, =0strr1, r0;disaable XXIRQ 00-3, ddma reeq,ackk, timmer 0,1 outtputldrr0, =IOP

43、PDATAldr r1, r0;readd inpuut dattamovpc, r14;*InitTimmerldrr0, =TMOODldrr1, =0strr1, r0;disaable ttimer 0,1movpc, r14;*UART_DIIV_CNTT0EQU26UART_DIIV_CNTT1EQU0InitUarrtldrr0, =ULCCON0ldrr1, =DATTA8b :OR: SSTOPb11 :OR PARITTY_NOstrr1, r0ldrr00, =UCCON0ldrr11, =RXX_STATT_INT|9strr11, r00ldrr00, =UBBRDI

44、V00ldrr11, =UAART_DIIV_CNTT04|UART_DIV_CCNT1strr11, r00;if UUART_DDIV_CNNT1=xxxx0 bbaud rrate = MCLKK/(UARRT_DIVV_CNT00+1)/116;if UAART_DIIV_CNTT1=xxxx1 baaud raate = MCLK/(UARTT_DIV_CNT0+1)/166/16ldrr00, =URRXBUF00ldrr11, r00;readd rx ddataldrr00, =ULLCON1ldrr11, =DAATA8b :OR: STOPbb1 :ORR PARIITY_

45、NOOstrr11, r00ldrr00, =UCCON1ldrr11, =RXX_STATT_INT|9strr11, r00ldrr00, =UBBRDIV11ldrr11, =UAART_DIIV_CNTT04|UART_DIV_CCNT1strr11, r00;if UUART_DDIV_CNNT1=xxxx0 bbaud rrate = MCLKK/(UARRT_DIVV_CNT00+1)/116;if UAART_DIIV_CNTT1=xxxx1 baaud raate = MCLK/(UARTT_DIV_CNT0+1)/166/16ldrr00, =URRXBUF11ldrr11

46、, r00;readd rx ddatamovpcc, r144;*InitStaackmrsr00, cpssrbicr00, r0, #PSRR_MODEE_MASKKorrr11, r0, #PSRR_UNDEEF_MODDE|NO_INTmsrcppsr_cxxsf, rr1;UndeefModeeldrspp,=UnddefStaackorrr11, r0, #PSRR_ABORRT_MODDE|NO_INTmsrcppsr_cxxsf, rr1;AborrtModeeldrspp, =AbbortSttackorrr11, r0, #PSRR_IRQ_MODE|NO_INNTmsr

47、cppsr_cxxsf, rr1;IRQMModeldrspp, =IRRQStacckorrr11, r0, #PSRR_FIQ_MODE|NO_INNTmsrcppsr_cxxsf, rr1;FIQMModeldrspp, =FIIQStacckorrr11, r0, #PSRR_SVC_MODE|NO_INNTmsrcppsr_cxxsf, rr1;SVCMModeldrspp, =SVVCStacckmovpcc, r144;*EXPORTTInitSSystemmInitSysstemmovr112, r114blIniitMemooryblIniitStacckblIniitPor

48、ttblIniitUarttblIniitTimeerblIniitInteerruptt;ldrrr0, =00 x110000000 ;CCache Flushh ;movrr1, #00;movrr2, #2256 ;1;strrr1, rr0, #4;subsr2, rr2, #11;bne%B1movpcc, r122;*IRQ_SERRVICE;usinng I_IISPR rregistter. IMPORTTpIrqSStartIMPORTTpIrqFFinishhIMPORTTpIrqHHandleer;nopp;ldrrr0, =TMOD;ldrrr1,r0;anddr1,

49、r1, #&37;strrr1, r0ldrr44, =INNTOFFSSET ldrrr4, r4 movvr1, rr4, lssr #2 movvr0, #1 movvr0, rr0, lssl r1 ldrrr1, =INTPNND strrr0, r1;cleaar intterruppt pennding bit ldrrr1, =pIrqSStart ldrrr1, r1 cmppr1, #0 movvnelr, ppc; .+88 movvnepc, rr1 ldrrr1, =pIrqHHandleer ldrrr1, r1 cmppr1, #0 movvnelr, ppc m

50、ovvnepc, rr1 ldrr11, =pIIrqFinnishldrr11, r11cmpr11, #0movnelr, ppc; .+88movnepc, rr1cmpr00, #0movnelr, ppcmovnepc, rr0 ldmfdsp!, r0;IRQmsrsppsr_cxxsf, rr0ldmfdsp!, r0-rr12, ppc;*AREA HHiVecttor, DDATA, READWWRITE_RAM_ENND_ADDDREQU0 x0100000000(_RAAM_ENDD_ADDRR-0 x6000)UserStaack#256;xxxxxxa00SVCSta

51、cck#256;xxxxxxb00UndefSttack#256;xxxxxxc00AbortSttack#256;xxxxxxd00IRQStacck#256;xxxxxxe00FIQStacck#0;xxxxxxf00MAP(_RAM_EEND_ADDDR-0 xx100)SYS_RSTT_VECTTOR#4UDF_INSS_VECTTOR#4SWI_SVCC_VECTTOR#4INS_ABTT_VECTTOR#4DAT_ABTT_VECTTOR#4RESERVEED_VECCTOR#4IRQ_SVCC_VECTTOR#4FIQ_SVCC_VECTTOR#4EXPORTTSYS_RRST_

52、VEECTOREXPORTTUDF_IINS_VEECTOREXPORTTSWI_SSVC_VEECTOREXPORTTINS_AABT_VEECTOREXPORTTDAT_AABT_VEECTOREXPORTTRESERRVED_VVECTORREXPORTTIRQ_SVVC_VECCTOREXPORTTFIQ_SSVC_VEECTOREND引入S3C45510相关系系统配置寄存存器的地址1INCLUUDEs3c45100.s引入s3c45510.s文文件后，syysinitt.s就包含含了很多与处处理器相关的的配置寄存器器的地址， 从而可以在在后续的配置置程序中方便便引用。定义用于配置RR

53、OM和RAAM的宏3RomBaaseAdddrEQU04RomEnndAddrrEQU&205RamBaaseAdddrEQU&1006RamEnndAddrrEQU&200行3-6定义的的这些宏将用于于初始化MeemCfgPPara内存存表，用于初初始化ROMMCON0和和DRAMCCON0配置置寄存器。定义用于配置SSYSCFGG的宏8AREAtext, CODEE, REAADONLYY910SFR_BASEEQU0 x3fff;0 x3fff0000011SRAMM_BASEEEQU0 x3f8;0 x3f800000行8定义一段代代码textt，该段将放放入RO段。行10-11定定义

54、了2个宏宏，用于对SSYSCFGG寄存器进行行初始化。定义用于初始化化内存的函数数InitMMemoryy14InittMemorry15ldrr0, =SYSCFFG16ldrr1, =SDRAMM_ITF :OR: SFR_BBASE16 :OOR: SRRAM_BAASE66 :OR: CACHHE_ALLL :OR: CACHHE_EN17strr1, r01819ldrr0, =CLKCOON20ldrr1, =021strr1, r02223ldrr0, =EXTACCON024ldrr1, =0 x0ffff0ffff25strr1, r026ldrr0, =EXTACCON12

55、7ldrr1, =0 x0ffff0ffff28strr1, r02930ldrr0, =EXTDBBWTH31ldrr1, =0 xfffff55632str r1, r03334adrr0, MMemCfggPara35ldmiiar0, r1-r11136ldrr0, =ROMCOON037stmiiar0, r1-r1113839movpc, rr144041MemCCfgParra42DCDRomBaaseAdddr100 :OR RomEnndAddrr20 :OR: &60;&108840060043DCD&10844206044DCD&10844206045DCD&108442

56、06046DCD&10844206047DCD&10844206048DCDRamBaaseAdddr100 :OR: RamEEndAdddr200 :OR: &3988;&100000398849DCD&10044039850DCD&10044039851DCD&10044039852DCD&ce29983fd 行16定义了要要设置给SYYSCFG寄寄存器的值，根据 REF _Ref173923182 n h 3，设置的值有以下含义：SDRAM_IITF 0 x8000000000 表明使用的的是SDRAAMSFR_BASSE 0 x3fff 表明speccial rregistter b

57、aand baase poointerr的地址是00 x3ff00000SRAM_BAASE 0 x3f8 表明iinternnal SRRAM baase poointerr的地址是00 x3f800000行19-21设设置芯片的时时钟，将CLKCOON寄存器设设置为全0，采用non-divided clock行23-25将将EXTACCON0寄存存器设置为00 x0ffff0fff，即将exteernal I/O bband 00、1的TCCOS, TTACS, TCOH, TACCC都设置为77个主时钟周周期。行26-28将将EXTACCON1寄存器设置置为0 x0ffff0ffff，即

58、将eexternnal I/O bannd 2、3的TCOSS, TACCS, TCCOH, TTACC都设设置为7个主主时钟周期。行30-32将将EXTDBBWTH寄存存器设置为00 xfffff556，即ROM BANK00的dataa bus为为16位，SSDRAM的的data bus宽度度为32位。行34-37设设置ROMCCON0RREFEXTTCON这111个寄存器器，特别地，设设置ROMCCON0的起起始地址为00 x0，结束束地址为0 xx2000000-1，DDRAMCOON0的起始始位置位置00 x10000000，结结束0 x200000000-1。行39返回子程程序In

59、ittMemorry的调用处地址。行41-52定定义了一段数数组。定义用于初始化化内存的函数数InitMMemoryy54EXPOORTRemappMemorry55RemaapMemoory56adrr0, RRemapMMemParra57ldmiiar0, r1-r11158ldrr0, =ROMCOON059stmiiar0, r1-r11160nop61nop62ldrr0, =IRQ_SSVC_VEECTOR63ldrr1, =IRQ_SSERVICCE;IRQ_SVC_VVECTORR in rram, sso sett it aafter remapp64str r1, r06

60、566movpc, rr146768RemaapMemPPara69DCD&12044006070DCD&10844206071DCD&10844206072DCD&10844206073DCD&10844206074DCD&10844206075DCD&10000039876DCD&10044039877DCD&10044039878DCD&10044039879DCD&ce29983fd行54声明全局局函数RemmapMemmory。行56-59设设置ROMCCON0RREFEXTTCON这111个寄存器器，特别地，设设置ROMCCON0的起起始地址为00 x10000000，结结束地址为