S3C2410下WinCE6.0的启动过程详解

NKStartup（）的代码就不多解释了，注释已经很详细。该函数的最后又调用了KernelStart ()函数。注意这里的KernelStart()跟上面曾提到的KernelStart()是不一样的。这里KernelStart()的实现在文件C:\WINCE600\PRIVATE\WINCEOS\COREOS\NK\KERNEL\ARM\armtrap.s中，代码和反汇编的对比如下图所示。
可以看到，这里调用了KernelInit()和FirstSchedule()这两个函数。先说FirstSchedule()，它开始了WinCE6.0的第一个调度。它的实现跟KernelStart()在同一文件中，而实现代码跟WinCE5.0中完全一样。接下来，我们继续跟踪KernelInit()函数，其实现在文件C:\WINCE600\PRIVATE\WINCEOS\COREOS\NK\KERNEL\nkinit.c中，代码如下：

Code
//------------------------------------------------------------------------------
//KernelInit-Kernelinitializationbeforeschedulingthe1stthread
//------------------------------------------------------------------------------

voidKernelInit(void)
{
#ifdefDEBUG
g_pNKGlobal->pfnWriteDebugString(TEXT("WindowsCEKernelInit\r\n"));
#endif
APICallInit();//setupAPIset
HeapInit();//setupkernelheap
InitMemoryPool();//setupphysicalmemory
PROCInit();//initializeprocess
VMInit(g_pprcNK);//setupVMforkernel
THRDInit();//initializethreads
MapfileInit();

#ifdefDEBUG
g_pNKGlobal->pfnWriteDebugString(TEXT("Schedulingthefirstthread.\r\n"));
#endif
}

这段代码跟WinCE5.0中的结构基本一致，但实际上有很大的不同。跟WinCE6.0启动最紧密的函数是THRDInit ()，这之前都是做相应的初始化。THRDInit ()的实现在文件C:\WINCE600\PRIVATE\WINCEOS\COREOS\NK\KERNEL\thread.c中，代码如下：

Code
//------------------------------------------------------------------------------
//THRDInit-initializethreadhandling(calledatsystemstartup)
//------------------------------------------------------------------------------
voidTHRDInit(void)
{
LPBYTEpStack;

DEBUGLOG(1,g_pprcNK);

//dontallowthreadcreateonememorydropbelow1%available
if(g_cMinPageThrdCreateg_cMinPageThrdCreate=PageFreeCount/100;
}

//mapW32threadpriorityifOEMchooseto
if(g_pOemGlobal->pfnMapW32Priority){
BYTEprioMap[MAX_WIN32_PRIORITY_LEVELS];
inti;
memcpy(prioMap,W32PrioMap,sizeof(prioMap));
g_pOemGlobal->pfnMapW32Priority(MAX_WIN32_PRIORITY_LEVELS,prioMap);
//validatethethepriorityismono-increase
for(i=0;iif(prioMap[i]>=prioMap[i+1])
break;
}

DEBUGMSG((MAX_WIN32_PRIORITY_LEVELS-1)!=i,(L"ProcInit:InvalidprioritymapprovidedbyOEM,Ignored!\r\n"));
if((MAX_WIN32_PRIORITY_LEVELS-1)==i){
memcpy(W32PrioMap,prioMap,sizeof(prioMap));
}
}

//allocatememoryforthe1stthread
pCurThread=AllocMem(HEAP_THREAD);
DEBUGCHK(pCurThread);

dwCurThId=(DWORD)HNDLCreateHandle(&cinfThread,pCurThread,g_pprcNK)&~1;
DEBUGCHK(dwCurThId);

InitThreadStruct(pCurThread,(HANDLE)dwCurThId,g_pprcNK,THREAD_RT_PRIORITY_ABOVE_NORMAL);

if(g_pOemGlobal->cbCoProcRegSize){

DEBUGCHK(g_pOemGlobal->pfnInitCoProcRegs);
DEBUGCHK(g_pOemGlobal->pfnSaveCoProcRegs);
DEBUGCHK(g_pOemGlobal->pfnRestoreCoProcRegs);

//checkthedebugregisterrelatedvalues.
if(g_pOemGlobal->cbCoProcRegSize>MAX_COPROCREGSIZE){
g_pOemGlobal->cbCoProcRegSize=g_pOemGlobal->fSaveCoProcReg=0;
}else{
PNAMEpTmp=AllocName(g_pOemGlobal->cbCoProcRegSize);
DEBUGCHK(pTmp);
g_dwCoProcPool=pTmp->wPool;
FreeName(pTmp);
}
}else{
g_pOemGlobal->fSaveCoProcReg=FALSE;
}
DEBUGMSG(ZONE_SCHEDULE,(TEXT("cbCoProcRegSize=%d\r\n"),g_pOemGlobal->cbCoProcRegSize));

AddToDListHead(&g_pprcNK->thrdList,&pCurThread->thLink);
g_pprcNK->wThrdCnt++;

#ifdefSHx
SetCPUGlobals();
OEMCacheRangeFlush(0,0,CACHE_SYNC_ALL);
#endif

if(!OpenExecutable(NULL,TEXT("NK.EXE"),&g_pprcNK->oe,TOKEN_SYSTEM,NULL,0)){
LoadE32(&g_pprcNK->oe,&g_pprcNK->e32,0,0,0);
g_pprcNK->BasePtr=(LPVOID)g_pprcNK->e32.e32_vbase;
UpdateKmodVSize(&g_pprcNK->oe,&g_pprcNK->e32);
}

//create/setupstack
pStack=VMCreateStack(g_pprcNK,KRN_STACK_SIZE);
pCurThread->dwOrigBase=(DWORD)pStack;
pCurThread->dwOrigStkSize=KRN_STACK_SIZE;
pCurThread->tlsSecure=pCurThread->tlsNonSecure=pCurThread->tlsPtr=TLSPTR(pStack,KRN_STACK_SIZE);
pCurThread->hTok=TOKEN_SYSTEM;

//Saveoffthethreadsprogramcounterforgettingitsnamelater.
pCurThread->dwStartAddr=(DWORD)SystemStartupFunc;

MDSetupThread(pCurThread,(LPVOID)SystemStartupFunc,0,TH_KMODE,0);

CELOG_ThreadCreate(pCurThread,g_pprcNK,NULL);

MakeRun(pCurThread);
DEBUGMSG(ZONE_SCHEDULE,(TEXT("Scheduler:Createdmasterthread%8.8lx\r\n"),pCurThread));

}