分类： WINDOWS
2008-08-22 09:18:25
| 在Windows CE 6.0中，内核（Kenerl）和OEM代码被分成oal.exe、kernel.dll和kitl.dll三个部分，其中启动代码（startup）和OAL层的实现部分不再与内核链接生成NK.exe，取而代之的是启动代码（startup）和硬件相关且独立于内核的OAL层的实现部分编译成oal.exe，而与内核相关且独立于硬件的OAL层代码包含在kernel.dll中；内核无关传输层（KITL）的支持代码从OAL层分离出来编译成kitl.dll。 |
| 从表面上看，好像只是代码重新组合了一下，从帮助文档中BSP的移植过程看好像也是这么一回事，实际上，整个Windows CE 6.0内核布局发生了很大的改变。Windows CE 6.0的启动过程也是如此，如果你想按照Windows CE 5.0的启动顺序去分析Windows CE 6.0的启动顺序，可能会走到一个死胡同。主要是因为Windows CE 6.0在启动过程中调用了kernel.dll和kitl.dll两个动态链接库的原因，而且Windows CE6.0不再编译生成KernKitlProf.exe内核文件。 |
| 从Windows CE 6.0的帮助文档可以看出，WinCE6.0的启动只与oal.exe和kernel.dll有关，至于kitl.dll，只有将操作系统编译成具有KITL功能时才用到。分析Windows CE 6.0的启动过程实际上找到编译oal.exe和kernel.dll的源码位置。 |
| 首先看一下将WinCE6.0编译成诸如WinCE5.0所说的基本内核情况，即kern.exe。对于oal.exe源码位置比较容易找到，因为oal.exe是启动代码与硬件相关的OAL层实现文件编译而成，所以只需在BSP的OAL目录中便能找到。而对于kernel.dll，在BSP目录结构中，基本上无法找到kernel.dll的编译文件，所以必须从其他方面着手。 |
| 下面为WinCE 6.0的编译日志输出文件：makeimg.out在文件复制过程的一部分： |
| Copying E:\WINCE600\OSDesigns\xsbase270\xsbase270\RelDir\XSBase270_ARMV4I_Release\oal.exe to E:\WINCE600\OSDesigns\xsbase270\xsbase270\RelDir\XSBase270_ARMV4I_Release\nk.exe for debugger Copying E:\WINCE600\OSDesigns\xsbase270\xsbase270\RelDir\XSBase270_ARMV4I_Release\kern.dll to E:\WINCE600\OSDesigns\xsbase270\xsbase270\RelDir\XSBase270_ARMV4I_Release\kernel.dll for debugger |
| 从日志输出文件可以看出，在文件复制过程中，WinCE6.0编译器将oal.exe更名为nk.exe，而将kern.dll文件更名为kernel.dll，也就是说，kern.dll文件的实现部分就是kernel.dll的实现体。根据前面的分析，oal.exe是与硬件相关独立于内核的OAL层的实现部分，而kernel.dll为内核相关独立于硬件的OAL层的实现部分。同样可以从最后整合后的二进制配置文件ce.bib文件中看出端倪。 |
| ; @CESYSGEN IF CE_MODULES_NK nk.exe E:\WINCE600\OSDesigns\xsbase270\xsbase270\RelDir\XSBase270_ARMV4I_Release\oal.exe NK SHZ kitl.dll E:\WINCE600\OSDesigns\xsbase270\xsbase270\RelDir\XSBase270_ARMV4I_Release\kitl.dll NK SHZ kernel.dll E:\WINCE600\OSDesigns\xsbase270\xsbase270\RelDir\XSBase270_ARMV4I_Release\kern.dll NK SHZ ; @CESYSGEN ENDIF |
| 而kern.dll动态库在整个Windows CE6.0中没有显式编译过程，即没有一个sources文件有kern.dll的编译过程，所以只能从操作系统的编译文件Makefile中寻找其编译过程。下面看一下$(_PUBLICROOT)\common\CESYSGEN\makefile中的部分内容： |
| nk::$(NK_COMPONENTS) $(NK_REPLACE_COMPONENTS) @copy $(SG_INPUT_LIB)\oemstub.pdb $(SG_OUTPUT_OAKLIB) @copy $(SG_INPUT_LIB)\oemstub.lib $(SG_OUTPUT_OAKLIB) set TARGETTYPE=DYNLINK set TARGETNAME=kern set RELEASETYPE=OAK set DLLENTRY=NKStartup set DEFFILE=NO_DEF_FILE set TARGETLIBS= set SOURCELIBS=%%NKLIBS%% $(SG_INPUT_LIB)\nkmain.lib $(SG_INPUT_LIB)\fulllibc.lib $(MAKECMD) /NOLOGO NOLIBC=1 kern.dll |
| 从上述代码中可以发现，原来kern.dll动态库是从oemstub.lib编译而来，而且与nkmain.lib有关。 |
| 在理顺了上述文件的相互之间的关系之后，再来分析Windows CE 6.0的启动过程可能就比较容易啦。 |
| 在理清了上述文件的关系之后，便可以分析任意一款基于ARM微处理器的Windows CE 6.0的启动过程，现在以深圳亿道电子技术有限公司开发的基于PXA270 ARM开发平台为例，分析Windows CE 6.0操作系统启动过程。 |
| 1、Startup函数： |
| 从Windows CE 6.0的帮助文档可以看出，WinCE6.0的启动只与oal.exe和kernel.dll有关，至于kitl.dll，只有将操作系统编译成具有KITL功能时才用到。分析Windows CE 6.0的启动过程实际上找到编译oal.exe和kernel.dll的源码位置。 |
| oal.exe的通过Startup函数完成硬件的初始化。Startup.s代码与该硬件平台的Bootloader启动代码共用，其中PreInit函数主要完成将ARM处理器工作模式切换到管理员模式、同时关闭MMU，并检测系统启动原因,如果是热启动、即在该函数调用之前已经启动了Bootloader程序，相当基本硬件初始化已经完成，则直接跳转到OALStartUp函数中；否则需要进行硬件中断屏蔽、内存、系统时钟频率、电源管理等硬件的基本初始化过程。（具体过程见代码的分析） |
| $(_PLATFORMROOT)\xsbase270\src\common\Startup\Startup.s LEAF_ENTRY StartUp bl PreInit
tst r10, #RCSR_HARD_RESET
beq OALStartUp
tst r10, #RCSR_GPIO_RESET
bne Continue_StartUp
bl xlli_mem_init ;初始化内存控制器
ldr r0, =xlli_PMRCREGS_PHYSICAL_BASE;
ldr r0, [r0, #xlli_PSPR_offset];
mov r1, r10;
bl XllpPmValidateResumeFromSleep;
cmp r0, #0;
bne Failed_Sleep_Resume; Sleep_Resetldr r0, =xlli_PMRCREGS_PHYSICAL_BASE;
ldr r0, [r0, #xlli_PSPR_offset];
mov r1, r10;
b XllpPmGoToContextRestoration;
Failed_Sleep_Resume
ldr r1, =xlli_RCSR_SMR
bic r10, r10, r1
Continue_StartUp
bl xlli_intr_init; ;初始化中断控制器
bl EnableClks; ;使能内核时钟(内存/OS定时器/FFART时钟之需)
bl OALXScaleSetFrequencies ;设置系统频率
bl xlli_mem_Topt
bl xlli_mem_restart ;复位内存，使其处于工作模式
bl xlli_ost_init ;初始化操作系统定时器
bl xlli_pwrmgr_init ;初始化电源管理
bl xlli_IMpwr_init ;初始化内部存储器
b
ENTRY_END |
| 2、OALStartUp函数： |
| 在系统硬件初始化完毕之后，Startup调用OALStartUp函数，OALStartUp函数主要完成将OEMAddressTable表传递给内核；然后调用KernelStart函数跳转到内核OEMAddressTable表的主要作用表的每一个入口都定义了一个内存中的物理位置、内存的大小以及映射这物理地址的静态虚拟地址； |
|
◆静态虚拟内存地址被定义在缓冲存储器的范围之内；
◆内核可以创建非缓冲的内存地址指向到相同的物理地址；
◆对于同一物理地址，既有一个缓冲的虚拟内存地址，也有一个非缓冲的虚拟内存地址；
◆OEMAddressTable最后必须以0结尾；
◆对于MIPS和SHx类型的CPU，物理地址与虚拟地址的映射由CPU完成，无需创建OEMAddressTable |
| $(_PLATFORMROOT)\xsbase270\src\Inc\ Oemaddrtab_cfg.inc)： ALIGN g_oalAddressTable DCD 0x80000000, 0xA0000000,64; XSBASE270: SDRAM (64MB).
DCD 0x84000000, 0x5C000000,1; BULVERDE: Internal SRAM (64KB bank 0).
DCD 0x84100000, 0x58000000,1; BULVERDE: Internal memory PM registers.
DCD 0x84200000, 0x4C000000,1; BULVERDE: USB host controller.
DCD 0x84300000, 0x48000000,1; BULVERDE: Memory controller.
DCD 0x84400000, 0x44000000,1; BULVERDE: LCD controller.
DCD 0x84500000, 0x40000000,32; BULVERDE: Memory-mapped registers
DCD 0x86500000, 0x00000000,64; XSBASE270: nCS0: Boot Flash (64MB).
DCD 0x96600000, 0x3C000000,64; BULVERDE: PCMCIA S1 common memory space.
DCD 0x8A600000, 0x38000000,32; BULVERDE: PCMCIA S1 attribute memory space.
DCD 0x8C600000, 0x30000000,32; BULVERDE: PCMCIA S1 I/O space.
DCD 0x8E500000, 0x2C000000,64; BULVERDE: PCMCIA S0 common memory space.
DCD 0x92500000, 0x28000000,32; BULVERDE: PCMCIA S0 attribute memory space.
DCD 0x94500000, 0x20000000,32; BULVERDE: PCMCIA S0 I/O space.
DCD 0x96500000, 0xE0000000,1; XSBASE270: Zero-bank .
DCD 0x96600000, 0x14000000,1; XSBASE270: nCS5: eXpansion board header.
DCD 0x96600000, 0x10000000,64; XSBASE270: nCS4: USB2.0/IDE controller.
DCD 0x9A700000, 0x0C000000,1; XSBASE270: nCS3: SMSC 91C111 Ethernet controller.
DCD 0x9A800000, 0x0A000000,1; XSBASE270: nCS2 : Board registers (CPLD).
DCD 0x9A900000, 0x04000000,32; XSBASE270: nCS1: Secondary flash (32MB).
DCD 0x9F900000, 0x50000000,1; BULVERDE: Camera peripheral interface.
DCD 0x9FA00000, 0x14700000,1
DCD 0x00000000, 0x00000000,0;end of table
END $(_PLATFORMROOT)\xsbase270\src\oal\OalLib\Startup.sALIGN LEAF_ENTRY OALStartUp
add r0, pc, #g_oalAddressTable - (. + 8)
mov r11, r0
b KernelStart
nop
nop
nop
nop
nop
nop STALLb STALL ;Spin forever. |
| 3、KernelStart函数主要作用： |
|
◆完成OEMAddressTable表中的物理地址到虚拟地址和虚拟地址到物理地址之间的映射；
◆对存储器页表和内核参数区存储空间（RAM或DRAM）进行清零处理。
◆读出CPU的ID号，内核需要根据该ID决定ARM的MMU处理，因为ARMV6和ARMV6之前的ARM处理器的MMU处理过程有所区别；
◆设置并开启MMU和Cache，因为在Startup函数关闭MMU和Cache；
◆设置ARM处理器工作模式的SP指针，ARM处理器共用7种不同的工作模式（USER、FIQ、IRQ、Supervisor、Abort、Undefined、System），除用户模式(USER)和系统模式（System）之外，其他5种工作模式都有具有特定的SP指针寄存器（ARM处理器称其为影子寄存器）；
◆读取内核启动所需要的KDataStruct结构体；
◆调用ARMInit函数重新定位Windows CE内核参数pTOC和初始化OEMInitGlobals全局变量；
◆利用mov pc, r12指令跳转到kernel.dll的入口位置，即NKStartup函数中。 |
| $(_PRIVATEROOT)WINCEOS\COREOS\NK\LDR\ARM\armstart.s LEAF_ENTRY KernelStart
mov r11, r0 ;(r11) = &OEMAddressTable (save pointer)
mov r1, r11 ;(r1) = &OEMAddressTable (2nd argument to VaFromPa)
bl VaFromPa
mov r6, r0 ;(r6) = VA of OEMAddressTable
; convert base of PTs to Physical address
ldr r4, =PTs ;(r4) = virtual address of FirstPT
mov r0, r4 ;(r0) = virtual address of FirstPT
mov r1, r11 ;(r1) = &OEMAddressTable (2nd argument to PaFromVa)
bl VaFromPa
mov r10, r0 ;(r10) = ptr to FirstPT (physical)
; Zero out page tables & kernel data page
mov r0, #0 ;(r0-r3) = 0''''s to store
mov r1, #0
mov r2, #0
mov r3, #0
mov r4, r10 ; (r4) = first address to clear
add r5, r10, #KDEnd-PTs ; (r5) = last address + 1 18 stmia r4!, {r0-r3}
stmia r4!, {r0-r3}
cmp r4, r5
blo %B18
; read the architecture information
bl GetCpuId
mov r5, r0 LSR #16 ; r5 >>= 16
and r5, r5, #0x0000000f ; r5 &= 0x0000000f == architecture id
add r4, r10, #HighPT-PTs ; (r4) = ptr to high page table
cmp r5, #ARMv6 ; v6 or later? ; ARMV6_MMU
orrge r0, r10, #PTL2_KRW + PTL2_SMALL_PAGE + ARMV6_MMU_PTL2_SMALL_XN
; (r0) = PTE for 4K, kr/w u-/- page, uncached unbuffered, nonexecutable; PRE ARMV6_MMU; orrlt r0, r10, #PTL2_KRW + (PTL2_KRW << 2) + (PTL2_KRW << 4) + (PTL2_KRW << 6)
;Need to replicate AP bits into all 4 fields
orrlt r0, r0, #PTL2_SMALL_PAGE + PREARMV6_MMU_PTL2_SMALL_XN
;(r0) = PTE for 4K, kr/w u-/- page, uncached unbuffered, nonexecutable
str r0,[r4, #0xD0*4] ;store the entry into 4 slots to map 16K of primary page table
add r0,r0, #0x1000 ;step on the physical address
str r0,[r4, #0xD1*4]
add r0,r0, #0x1000 ;step on the physical address
str r0,[r4, #0xD2*4]
add r0,r0, #0x1000 ;step on the physical address
str r0,[r4, #0xD3*4]
add r8,r10, #ExceptionVectors-PTs ;(r8) = ptr to vector page
orr r0,r8, #PTL2_SMALL_PAGE ;construct the PTE (C=B=0)
cmp r5,#ARMv6 ;v6 or later? ; ARMV6_MMU
orrge r0, r0, #PTL2_KRW ; PRE ARMV6_MMU
orrlt r0, r0, #PTL2_KRW + (PTL2_KRW << 2) + (PTL2_KRW << 4) + (PTL2_KRW << 6)
; Need to replicate AP bits into all 4 fields for pre-V6 MMU
str r0,[r4, #0xF0*4] ;store entry for exception stacks and vectors
;other 3 entries now unused
add r9,r10,#KPage-PTs ;(r9) = ptr to kdata page
orr r0,r9,#PTL2_SMALL_PAGE ;(r0)=PTE for 4K (C=B=0) ; ARMV6_MMU (condition codes still set)
orrge r0, r0, #PTL2_KRW_URO ; No subpage access control, so we must set this all to kr/w+ur/o ; PRE ARMV6_MMU
orrlt r0, r0, #(PTL2_KRW << 0) + (PTL2_KRW << 2) + (PTL2_KRW_URO << 4)
;(r0) = set perms kr/w kr/w kr/w+ur/o r/o
str r0, [r4, #0xFC*4] ;store entry for kernel data page
orr r0,r4, #PTL1_2Y_TABLE ;(r0) = 1st level PTE for high memory section
add r1, r10, #0x4000
str r0, [r1, #-4] ; store PTE in last slot of 1st level table
add r10, r10, #0x2000 ; (r10) = ptr to 1st PTE for "unmapped space"
mov r0, #PTL1_SECTION
orr r0, r0, #PTL1_KRW ;(r0)=PTE for 0: 1MB (C=B=0, kernel r/w)
20 mov r1, r11 ;(r1) = ptr to OEMAddressTable array (physical)
25 ldr r2,[r1],#4 ;(r2) = virtual address to map Bank at
ldr r3,[r1],#4 ;(r3) = physical address to map from
ldr r4,[r1],#4 ;(r4) = num MB to map
cmp r4,#0 ;End of table?
beq %F29
ldr r12, =0x1FF00000
and r2, r2, r12 ;VA needs 512MB, 1MB aligned.
ldr r12, =0xFFF00000
and r3, r3, r12 ;PA needs 4GB, 1MB aligned.
add r2, r10, r2, LSR #18
add r0, r0, r3 ;(r0) = PTE for next physical page
28 str r0, [r2],#4
add r0, r0, #0x00100000 ;(r0) = PTE for next physical page
sub r4, r4, #1 ;Decrement number of MB left
cmp r4, #0
bne %B28 ;Map next MB
bic r0, r0,#0xF0000000 ;Clear Section Base Address Field
bic r0, r0, #0x0FF00000 ;Clear Section Base Address Field
b %B25 ;Get next element 29
sub r10, r10, #0x2000 ;(r10) = restore address of 1st level page table
ldr r12, =0xFFF00000 ;(r12) = mask for section bits
and r1, pc, r12 ;physical address of where we are
;NOTE: we assume that the KernelStart function never spam
across 1M boundary.
orr r0, r1, #PTL1_SECTION
orr r0, r0, #PTL1_KRW ;(r0) = PTE for 1M for current physical address, C=B=0, kernel r/w
add r7, r10, r1, LSR #18 ;(r7) = 1st level PT entry for the identity map
ldr r8, [r7] ;(r8) = saved content of the 1st-level PT
str r0, [r7] ;create the identity map
mov r1, #1
mtc15 r1, c3 ;Setup access to domain 0 and clear other
mtc15 r10, c2 ;setup translation base (physical of 1st level PT)
mov r0, #0
mcr p15, 0, r0, c8, c7, 0 ;Flush the I&D TLBs
mfc15 r1, c1
orr r1, r1, #0x007F ;changed to read-mod-write for ARM920 Enable: MMU, Align, DCache, WriteBuffer
cmp r5, #ARMv6 ;r5 still set ; ARMV6_MMU
orrge r1, r1, #0x3000 ;vector adjust, ICache
orrge r1, r1, #1<<23 ;V6-format page tables
orrge r1, r1, #ARMV6_U_BIT ;V6-set U bit, let A bit control unalignment support ; PRE ARMV6_MMU
orrlt r1, r1, #0x3200 ;vector adjust, ICache, ROM protection
ldr r0, VirtualStart
cmp r0, #0 ;make sure no stall on "mov pc,r0" below
mtc15 r1, c1 ;enable the MMU & Caches
mov pc, r0 ;& jump to new virtual address
nop
VStart ldr r2, =FirstPT ;(r2) = VA of 1st level PT
sub r7, r7, r10 ;(r7) = offset into 1st-level PT
str r8, [r2, r7] ;restore the temporary identity map
mcr p15, 0, r0, c8, c7, 0 ;Flush the I&D TLBs
; setup stack for each modes: current mode = supervisor mode
ldr sp, =KStack
add r4, sp, #KData-KStack ;(r4) = ptr to KDataStruct
; setup ABORT stack
mov r1, #ABORT_MODE:OR:0xC0
msr cpsr_c, r1 ;switch to Abort Mode w/IRQs disabled
add sp, r4, #AbortStack-KData
; setup IRQ stack
mov r2, #IRQ_MODE:OR:0xC0
msr cpsr_c, r2 ;switch to IRQ Mode w/IRQs disabled
add sp, r4, #IntStack-KData
; setup FIQ stack
mov r3, #FIQ_MODE:OR:0xC0
msr cpsr_c, r3 ;switch to FIQ Mode w/IRQs disabled
add sp, r4, #FIQStack-KData
; setup UNDEF stack
mov r3, #UNDEF_MODE:OR:0xC0
msr cpsr_c, r3 ;switch to Undefined Mode w/IRQs disabled
mov sp, r4 ;(sp_undef) = &KData
; switch back to Supervisor mode
mov r0, #SVC_MODE:OR:0xC0
msr cpsr_c, r0 ;switch to Supervisor Mode w/IRQs disabled
ldr sp, =KStack
; continue initialization in C
add r0, sp, #KData-KStack ;(r0) = ptr to KDataStruct
str r6, [r0, #pAddrMap] ;store VA of OEMAddressTable in KData
bl ARMInit ;call C function to perform the rest of initializations
; upon return, (r0) = entry point of kernel.dll
mov r12, r0
ldr r0, =KData
mov pc, r12 ;jump to entry of kernel.dll VirtualStart DCD VStart
ENTRY_END KernelStart |
| 4、ARMInit函数： |
| 在ARMInit之前，系统仍无法使用全局变量，因为系统的全局还在ROM区域，对于操作系统而言，出于安全考虑，只有XIP程序才有读取ROM区域数据的权利，对于大部分Windows CE 操作系统，只有将数据拷贝到RAM区域后才能进行读写，ARMInit函数中通过调用KernelRelocate函数对pTOC全局变量重新定位，定位之后，对内核启动所需要的KDataStruct结构体进行初始化，其中OEMInitGlobals便是交换oal.exe和kernel.dll之间的全局指针，ARMInit函数返回kernel.dll的入口位置。并在KernelStart函数最后利用mov pc, r12指令跳转到kernel.dll的入口位置，即NKStartup函数中。 |
|
$(_PRIVATEROOT)WINCEOS\COREOS\NK\LDR\ARM\arminit.c LPVOID ARMInit (struct KDataStruct *pKData){ /* Initialize kernel globals */
KernelRelocate (pTOC);
/* The only argument passed to the entry point of kernel.dll is the address */
/* of KData, we need to put everything we need to pass to in in KData. */
pKData->dwTOCAddr = (DWORD) pTOC;
pKData->dwOEMInitGlobalsAddr = (DWORD) OEMInitGlobals;
SetOsAxsDataBlockPointer(pKData);
return FindKernelEntry (pTOC); } |
| 5、NKStartup函数： |
| 硬件平台初始化完成后，oal.exe的启动任务基本完成，余下的启动工作由内核相关且独立于内核的OAL层实现体kernel.dll接管。kernel.dll主要作用： |
|
◆从结构体参数KDataStruct * pKData提取内核启动时所必须的全局变量，同时初始化内核全局变量；
◆定位对Windows CE 6.0特有的OEMGLOBAL结构体的初始化函数OEMInitGlobals地址，该结构体构建了内核和OAL层之间进行通信的桥梁。在OEMGLOBAL结构体定义了OAL层所必须的函数，该结构体在oemglobal.c文件中被初始化，并被编译在OEMMain.lib和OEMMain_StaticKITL.lib两个库中，如果OAL链接这两个库，则必须要有该结构体中函数实现体；
◆通过调用ARMSetup设置物理地址和非缓冲的虚拟内存地址的映射、ARM中断向量以及内核模式所需要的堆栈。
◆调用OEMInitDebugSerial函数初始化调试串口；
◆调用OEMInit进行平台初始化；
需要注意的时，NKStartup函数调用OEMInitDebugSerial和OEMInit函数的过程与Windows CE 6.0之前的版本完全不同，这是因为在Windows CE 6.0以前的版本中，由于内核（kernel）、OAL和KITL编译在一个可执行的文件中，它们之间的共享变量只需简单利用extern关键字申明便可相互之间进行访问，而在Windows CE 6.0中，由于内核（kernel）、OAL和KITL被编译成不同的可执行文件，变量之间的相互访问无法使用extern关键字实现共享，即内核无法使用extern DWORD varX方法访问OAL层的变量varX，当然OAL层的实现体同样无法通过同样的方式访问内核变量。为实现内核和OAL访问共享信息，Windows CE 6.0定义了OEMGLOBAL和GLOBAL两个结构体。
|
调用KernelFindMemory()函数分割RAM区域，在Windows CE操作系统中，RAM空间主要分为存储内存和程序内存，存储内存主要为文件的存储空间，包括内核文件和复制到系统中所有目标文件，程序内存为运行程序时所需要的存储空间。 |
| ◆KernelStart ()启动内核。 |
| $(_PRIVATEROOT)\WINCEOS\COREOS\NK\KERNEL\ARM\mdarm.c
void NKStartup (struct KDataStruct * pKData)
{
PFN_OEMInitGlobals pfnInitGlob;
PFN_DllMain pfnKitlEntry;
DWORD dwCpuId = GetCpuId ();
// (1) pickup arguments from the nk loader
g_pKData = pKData;
pTOC = (const ROMHDR *) pKData->dwTOCAddr;
g_pOEMAddressTable = (PADDRMAP) pKData->pAddrMap;
/* get architecture id and update page protection attributes */
pKData->dwArchitectureId = (dwCpuId >> 16) & 0xf;
if (pKData->dwArchitectureId >= ARMArchitectureV6)
{
// v6 or later
pKData->dwProtMask = PG_V6_PROTECTION;
pKData->dwRead = PG_V6_PROT_READ;
pKData->dwWrite = PG_V6_PROT_WRITE;
pKData->dwKrwUro = PG_V6_PROT_URO_KRW;
} else {
// pre-v6
pKData->dwProtMask = PG_V4_PROTECTION;
pKData->dwRead = PG_V4_PROT_READ;
pKData->dwWrite = PG_V4_PROT_WRITE;
pKData->dwKrwUro = PG_V4_PROT_URO_KRW;
pKData->dwKrwUno = PG_V4_PROT_UNO_KRW;
}
// initialize nk globals
FirstROM.pTOC = (ROMHDR *) pTOC;
FirstROM.pNext = 0;
ROMChain = &FirstROM;
KInfoTable[KINX_PTOC] = (long)pTOC;
KInfoTable[KINX_PAGESIZE] = VM_PAGE_SIZE;
g_ppdirNK = (PPAGEDIRECTORY) &ArmHigh->firstPT[0];
pKData->pNk = g_pNKGlobal;
// (2) find entry of oal
pfnInitGlob = (PFN_OEMInitGlobals) pKData->dwOEMInitGlobalsAddr;
// no checking here, if OAL entry point doesn''''t exist, we can''''t continue
g_pOemGlobal = pfnInitGlob (g_pNKGlobal);
g_pOemGlobal->dwMainMemoryEndAddress = pTOC->ulRAMEnd;
pKData->pOem = g_pOemGlobal;
// setup globals
pVMProc = g_pprcNK;
pActvProc = g_pprcNK;
g_pNKGlobal->pfnWriteDebugString = g_pOemGlobal->pfnWriteDebugString;
// (3) setup vectors, UC mappings, mode stacks, etc.
ARMSetup ();
// (4) common startup code.
// try to load KITL if exist
if ((pfnKitlEntry = (PFN_DllMain) g_pOemGlobal->pfnKITLGlobalInit) ||
(pfnKitlEntry = (PFN_DllMain) FindROMDllEntry (pTOC, KITLDLL))) {
(* pfnKitlEntry) (NULL, DLL_PROCESS_ATTACH, (DWORD) NKKernelLibIoControl);
} #ifdef DEBUG
CurMSec = dwPrevReschedTime = (DWORD) -200000; // ~3 minutes before wrap #endif
OEMInitDebugSerial ();
// debugchk only works after we have something to print to.
DEBUGCHK (pKData == (struct KDataStruct *) PUserKData);
DEBUGCHK (pKData == &ArmHigh->kdata);
OEMWriteDebugString ((LPWSTR)NKSignon);
/* Copy interlocked api code into the kpage */
DEBUGCHK(sizeof(struct KDataStruct) <= FIRST_INTERLOCK);
DEBUGCHK((InterlockedEnd-InterlockedAPIs)+FIRST_INTERLOCK <= 0x400);
memcpy((char *)g_pKData+FIRST_INTERLOCK, InterlockedAPIs, InterlockedEnd-InterlockedAPIs);
/* setup processor version information */
CEProcessorType = (dwCpuId >> 4) & 0xFFF;
CEProcessorLevel = 4;
CEProcessorRevision = (WORD) dwCpuId & 0x0f;
CEInstructionSet = PROCESSOR_ARM_V4I_INSTRUCTION;
RETAILMSG (1, (L"ProcessorType=%4.4x Revision=%d\r\n", CEProcessorType, CEProcessorRevision));
RETAILMSG (1, (L"OEMAddressTable = %8.8lx\r\n", g_pOEMAddressTable));
OEMInit(); // initialize firmware
// flush I&D TLB
OEMCacheRangeFlush (NULL, 0, CACHE_SYNC_FLUSH_TLB);
KernelFindMemory();
DEBUGMSG (1, (TEXT("NKStartup done, starting up kernel.\r\n")));
KernelStart ();
// never returned
DEBUGCHK (0); } |
|
6、KernelSstart函数：
这里的KernelStart函数与前面的KernelStart函数的属于两个完全不同的函数，NKStartup函数中调用的KernelStart函数为$(_PRIVATEROOT)\WINCEOS\COREOS\NK\KERNEL\ARM\armtrap.s文件中的KernelStart函数，主要完成调用内核初始化函数KernelInit，并跳转到操作系统的第一个启动的任务。 |
|
LEAF_ENTRY KernelStart
ldr r4, =KData ; (r4) = ptr to KDataStruct
ldr r0, =APIRet
str r0, [r4, #pAPIReturn] ; set API return address
mov r1, #SVC_MODE
msr cpsr_c, r1 ; switch to Supervisor Mode w/IRQs enabled
CALL KernelInit ; initialize scheduler, etc.
mov r0, #0 ; no current thread
mov r1, #ID_RESCHEDULE
b FirstSchedule
ENTRY_END |
| 7、KernelInit函数： |
| Windows CE 6.0的内核初始化函数同其他版本的内核初始化函数基本相近，主要完成在启动第一个线程前对内核进行初始化，主要包括API函数集初始化、堆的初始化、初始化内存池、进程初始化、线程初始化和文件映射初始化等操作。 |
| void KernelInit (void)
{ #ifdef DEBUG
g_pNKGlobal->pfnWriteDebugString (TEXT("Windows CE KernelInit\r\n")); #endif
APICallInit ();// setup API set
HeapInit ();// setup kernel heap
InitMemoryPool ();// setup physical memory
PROCInit ();// initialize process
VMInit (g_pprcNK);// setup VM for kernel
THRDInit ();// initialize threadsv
MapfileInit (); #ifdef DEBUG
g_pNKGlobal->pfnWriteDebugString (TEXT("Scheduling the first thread.\r\n"));
#endif } |
| 8、FirstSchedule： |
| FirstSchedule函数为Windows CE操作系统启动过程中最后无条件跳转的一个函数，windows CE进行第一个调度，实际为一个空闲线程，因为windows CE系统还没有完成启动，只有当windows CE完全启动并进入稳定状态，然后启动文件系统filesys.dll,设备管理device.dll,窗体图像子系统gews.dll和shell程序explore.exe。 |
