S3C2410下WinCE6.0的启动过程详解

equiredforthestacks.
cmpr5,#ARMv6;v6orlater?
;ARMV6_MMU
orrger0,r0,#PTL2_KRW
;PREARMV6_MMU
orrltr0,r0,#PTL2_KRW+(PTL2_KRW<2)+(PTL2_KRW<4)+(PTL2_KRW<6)
;NeedtoreplicateAPbitsintoall4fieldsforpre-V6MMU

strr0,[r4,#0xF0*4];storeentryforexceptionstacksandvectors
;other3entriesnowunused

addr9,r10,#KPage-PTs;(r9)=ptrtokdatapage
orrr0,r9,#PTL2_SMALL_PAGE;(r0)=PTEfor4K(C=B=0)

;ARMV6_MMU(conditioncodesstillset)
orrger0,r0,#PTL2_KRW_URO;Nosubpageaccesscontrol,sowemustsetthisalltokr/w+ur/o
;PREARMV6_MMU
orrltr0,r0,#(PTL2_KRW<0)+(PTL2_KRW<2)+(PTL2_KRW_URO<4)
;(r0)=setpermskr/wkr/wkr/w+ur/or/o
strr0,[r4,#0xFC*4];storeentryforkerneldatapage
orrr0,r4,#PTL1_2Y_TABLE;(r0)=1stlevelPTEforhighmemorysection
addr1,r10,#0x4000
strr0,[r1,#-4];storePTEinlastslotof1stleveltable

;Fillinfirstlevelpagetableentriestocreate"staticallymapped"regions
;fromthecontentsoftheOEMAddressTablearray.
;
;(r5)=architectureid
;(r9)=ptrtoKDatapage
;(r10)=ptrto1stlevelpagetable
;(r11)=ptrtoOEMAddressTablearray

addr10,r10,#0x2000;(r10)=ptrto1stPTEfor"unmappedspace"

movr0,#PTL1_SECTION
orrr0,r0,#PTL1_KRW;(r0)=PTEfor0:1MB(C=B=0,kernelr/w)
20movr1,r11;(r1)=ptrtoOEMAddressTablearray(physical)

25ldrr2,[r1],#4;(r2)=virtualaddresstomapBankat
ldrr3,[r1],#4;(r3)=physicaladdresstomapfrom
ldrr4,[r1],#4;(r4)=numMBtomap

cmpr4,#0;Endoftable?
beq%F29

ldrr12,=0x1FF00000
andr2,r2,r12;VAneeds512MB,1MBaligned.

ldrr12,=0xFFF00000
andr3,r3,r12;PAneeds4GB,1MBaligned.

addr2,r10,r2,LSR#18
addr0,r0,r3;(r0)=PTEfornextphysicalpage

28strr0,[r2],#4
addr0,r0,#0x00100000;(r0)=PTEfornextphysicalpage

subr4,r4,#1;DecrementnumberofMBleft
cmpr4,#0
bne%B28;MapnextMB

bicr0,r0,#0xF0000000;ClearSectionBaseAddressField
bicr0,r0,#0x0FF00000;ClearSectionBaseAddressField
b%B25;Getnextelement

29
subr10,r10,#0x2000;(r10)=restoreaddressof1stlevelpagetable

;Theminimalpagemappingsaresetup.InitializetheMMUandturniton.

;therearesomeCPUswithpipelineissuesthatrequiresidentitymappingbeforeturningonMMU.
;WellcreateanidentitymappingfortheaddresswelljumptowhenturningonMMUonandremove
;themappingafterweturnonMMUandrunningonVirtualaddress.

ldrr12,=0xFFF00000;(r12)=maskforsectionbits
andr1,pc,r12;physicaladdressofwhereweare
;NOTE:weassumethattheKernelStartfunctionneverspamacross1Mboundary.
orrr0,r1,#PTL1_SECTION
orrr0,r0,#PTL1_KRW;(r0)=PTEfor1Mforcurrentphysicaladdress,C=B=0,kernelr/w
addr7,r10,r1,LSR#18;(r7)=1stlevelPTentryfortheidentitymap
ldrr8,[r7];(r8)=savedcontentofthe1st-levelPT
strr0,[r7];createtheidentitymap

movr1,#1
mtc15r1,c3;Setupaccesstodomain0andclearother
mtc15r10,c2;setuptranslationbase(physicalof1stlevelPT)

movr0,#0
mcrp15,0,r0,c8,c7,0;FlushtheI&DTLBs

mfc15r1,c1
orrr1,r1,#0x007F;changedtoread-mod-writeforARM920Enable:MMU,Align,DCache,WriteBuffer

cmpr5,#ARMv6;r5stillset
;ARMV6_MMU
orrger1,r1,#0x3000;vectoradjust,ICache
orrger1,r1,#1<23;V6-formatpagetables
orrger1,r1,#ARMV6_U_BIT;V6-setUbit,letAbitcontrolunalignmentsupport
;PREARMV6_MMU
orrltr1,r1,#0x3200;vectoradjust,ICache,ROMprotection

ldrr0,VirtualStart
cmpr0,#0;makesurenostallon"movpc,r0"below
mtc15r1,c1;enabletheMMU&Caches
movpc,r0;&jumptonewvirtualaddress
nop

;MMU&cachesnowenabled.
;
;(r10)=physcialaddressof1stlevelpagetable
;(r7)=entryin1stlevelPTforidentitymap
;(r8)=saved1stlevelPTsaveat(r7)
VStartldrr2,=FirstPT;(r2)=VAof1stlevelPT
subr7,r7,r10;(r7)=offsetinto1st-levelPT
strr8,[r2,r7];restorethetemporaryidentitymap
mcrp15,0,r0,c8,c7,0;FlushtheI&DTLBs

;
;setupstackforeachmodes:currentmode=supervisormode
;
ldrsp,=KStack
addr4,sp,#KData-KStack;(r4)=ptrtoKDataStruct

;setupABORTstack
movr1,#ABORT_MODE:OR:0xC0
msrcpsr_c,r1;switchtoAbortModew/IRQsdisabled
addsp,r4,#AbortStack-KData

;setupIRQstack
movr2,#IRQ_MODE:OR:0xC0
msrcpsr_c,r2;switchtoIRQModew/IRQsdisabled
addsp,r4,#IntStack-KData

;setupFIQstack
movr3,#FIQ_MODE:OR:0xC0
msrcpsr_c,r3;switchtoFIQModew/IRQsdisabled
addsp,r4,#FIQStack-KData

;setupUNDEFstack
movr3,#UNDEF_MODE:OR:0xC0
msrcpsr_c,r3;switchtoUndefinedModew/IRQsdisabled
movsp,r4;(sp_undef)=&KData

;switchbacktoSupervisormode
movr0,#SVC_MODE:OR:0xC0
msrcpsr_c,r0;switchtoSupervisorModew/IRQsdisabled
ldrsp,=KStack

;continueinitializationinC
addr0,sp,#KData-KStack;(r0)=ptrtoKDataStruct
strr6,[r0,#pAddrMap];storeVAofOEMAddressTableinKData
blARMInit;callCfunctiontoperformtherestofinitializations
;uponreturn,(r0)=entrypointofkernel.dll

movr12,r0
ldrr0,=KData
movpc,r12;jumptoentryofkernel.dll