config.c

DOS操作系统源代码,研究操作系统用. 包括了dos的所有源文件

				if (*pTmp == '\r' || *pTmp == EOF) 
				    break;
			}

			if (pTmp - szLine >= LINESIZE)
			    break;
		
			if (*pTmp == EOF) 
			    bEof = TRUE;

			*pTmp = '\0';
			pLineStart = pLine;

			/* Skip leading white space and get verb.               */
			pLine = scan(pLine, szBuf);

			/* Translate the verb to lower case ...                 */
			for(pTmp = szBuf; *pTmp != '\0'; pTmp++)
				*pTmp = tolower(*pTmp);

			/* If the line was blank, skip it.  Otherwise, look up  */
			/* the verb and execute the appropriate function.       */
			if(*szBuf != '\0')
			{
				pEntry = LookUp(commands, szBuf);
					
				if(pEntry -> pass < 0 || pEntry -> pass == nPass)
				{        
					if (!singleStep || !SkipLine(pLineStart))
					{
						skipwh(pLine);
						
						if('=' != *pLine)
							CfgFailure(pLine);
						else (*(pEntry -> func))(++pLine);
					}
				}
			}
skipLine:               nCfgLine++;
			pLine += strlen(pLine) + 1;
		}
	}
	dos_close(nFileDesc);
}

struct table *LookUp(struct table *p, BYTE *token)
{
	while(*(p -> entry) != '\0')
	{
		if(strcmp(p -> entry, token) == 0)
			break;
		else
			++p;
	}
	return p;
}
					    
BOOL    SkipLine(char *pLine)
{
	char    kbdbuf[16];
	keyboard *kp = (keyboard *)kbdbuf;
	char    *pKbd = &kp->kb_buf[0];

	kp->kb_size = 12;
	kp->kb_count = 0;
	
	printf("%s [Y,N]?", pLine);
	sti(kp);
	
	pKbd = skipwh(pKbd);
	
	if (*pKbd == 'n' || *pKbd == 'N')
		return TRUE;        
	    
	return FALSE;
}

BYTE *GetNumArg(BYTE *pLine, COUNT *pnArg)
{
	/* look for NUMBER                               */
	pLine = skipwh(pLine);
	if(!isnum(pLine))
	{
		CfgFailure(pLine);
		return (BYTE *)0;
	}
	return GetNumber(pLine, pnArg);
}


BYTE *GetStringArg(BYTE *pLine, BYTE *pszString)
{
	/* look for STRING                               */
	pLine = skipwh(pLine);

	/* just return whatever string is there, including null         */
	return scan(pLine, pszString);
}

static VOID Buffers(BYTE *pLine)
{
	COUNT nBuffers;

	/* Get the argument                                             */
	if(GetNumArg(pLine, &nBuffers) == (BYTE *)0)
		return;

	/* Got the value, assign either default or new value            */
	Config.cfgBuffers = max(Config.cfgBuffers, nBuffers);
}

static VOID Files(BYTE *pLine)
{
	COUNT nFiles;

	/* Get the argument                                             */
	if(GetNumArg(pLine, &nFiles) == (BYTE *)0)
		return;

	/* Got the value, assign either default or new value            */
	Config.cfgFiles = max(Config.cfgFiles, nFiles);
}

static VOID Lastdrive(BYTE *pLine)
{
	/* Format:   LASTDRIVE = letter         */
	COUNT   nFiles;
	BYTE    drv;

	pLine = skipwh(pLine);
	drv = *pLine & ~0x20;   

	if (drv < 'A' || drv > 'Z')
	{        
		CfgFailure(pLine);
		return;
	}
	drv -= 'A';
	Config.cfgLastdrive = max(Config.cfgLastdrive, drv);
}

static VOID Switchar(BYTE *pLine)
{
	/* Format: SWITCHAR = character         */
	
	GetStringArg(pLine, szBuf);
	switchar = *szBuf;
}

static VOID Fcbs(BYTE *pLine)
{
	/*  Format:     FCBS = totalFcbs [,protectedFcbs]    */
	
	if ((pLine = GetNumArg(pLine, &Config.cfgFcbs)) == 0)
	    return;

	pLine = skipwh(pLine);

	if (*pLine == ',')
	    GetNumArg(++pLine, &Config.cfgProtFcbs);

	if (Config.cfgProtFcbs > Config.cfgFcbs)
	    Config.cfgProtFcbs = Config.cfgFcbs;
}

static VOID Country(BYTE *pLine)
{
	/* Format: COUNTRY = countryCode, [codePage], filename  */
	UWORD   ctryCode;
	UWORD   codePage;

	if ((pLine = GetNumArg(pLine, &ctryCode)) == 0)
	    return;
	    
	pLine = skipwh(pLine);
	if (*pLine == ',')
	{
		pLine = skipwh(pLine);
		
		if (*pLine == ',') 
		{
		    codePage = 0;
		    ++pLine;
		} else {
		    if ((pLine = GetNumArg(pLine, &codePage)) == 0)
			return;
		}

		pLine = skipwh(pLine);
		if (*pLine == ',')
		{
		    GetStringArg(++pLine, szBuf);
		    
		    if (LoadCountryInfo(szBuf, ctryCode, codePage))
			return;
		}
	}
	CfgFailure(pLine);
}

static VOID Stacks(BYTE *pLine)
{
	/* Format:  STACKS = stacks [, stackSize]       */
	pLine = GetNumArg(pLine, &Config.cfgStacks);

	if (*pLine == ',')
	    GetNumArg(++pLine, &Config.cfgStackSize);

	if (Config.cfgStacks)
	{
	    if (Config.cfgStackSize < 32) Config.cfgStackSize = 32;
	    if (Config.cfgStackSize > 512) Config.cfgStackSize = 512;
	    if (Config.cfgStacks > 64) Config.cfgStacks = 64;
	}
}

static VOID InitPgm(BYTE *pLine)
{
	/* Get the string argument that represents the new init pgm     */
	pLine = GetStringArg(pLine, Config.cfgInit);

	/* Now take whatever tail is left and add it on as a single     */
	/* string.                                                      */
	strcpy(Config.cfgInitTail, pLine);

	/* and add a DOS new line just to be safe                       */
	strcat(Config.cfgInitTail, "\r\n");
}

static VOID   Break(BYTE *pLine)
{
	/* Format:      BREAK = (ON | OFF)      */
	BYTE *pTmp;

	GetStringArg(pLine, szBuf);
	break_ena = strcmp(szBuf, "OFF")? 1 : 0;
}

static VOID Device(BYTE *pLine)
{
	VOID FAR *driver_ptr;
	BYTE *pTmp;
	exec_blk eb;
	struct dhdr FAR *dhp;
	struct dhdr FAR *next_dhp;
	UWORD dev_seg = (((ULONG)FP_SEG(lpBase) << 4) + FP_OFF(lpBase) + 0xf) >> 4;
	
	/* Get the device driver name                                   */
	GetStringArg(pLine, szBuf);

	/* The driver is loaded at the top of allocated memory.         */             
	/* The device driver is paragraph aligned.                      */
	eb.load.reloc = eb.load.load_seg = dev_seg;
	dhp = MK_FP(dev_seg, 0);
	
#ifdef DEBUG
	printf("Loading device driver %s at segment %04x\n", 
	       szBuf, dev_seg);
#endif

	if (DosExec(3, &eb, szBuf) == SUCCESS)
	{
	    while(FP_OFF(dhp) != 0xFFFF)
	    {
		next_dhp = MK_FP(FP_SEG(dhp), FP_OFF(dhp -> dh_next));
		dhp -> dh_next = nul_dev.dh_next; 
		link_dhdr(&nul_dev, dhp, pLine); 
		dhp = next_dhp;
	    } 
	} else CfgFailure(pLine);
}

static VOID CfgFailure(BYTE *pLine)
{
	BYTE *pTmp = pLineStart;

	printf("CONFIG.SYS error in line %d\n", nCfgLine);
	printf(">>>%s\n", pTmp);
	while(++pTmp != pLine)
		printf(" ");
	printf("^\n");
}

#ifndef KDB
static BYTE FAR *
KernelAlloc(WORD nBytes)
{
	BYTE FAR *lpAllocated;

	lpBase = AlignParagraph(lpBase);
	lpAllocated = lpBase;

	if (0x10000 - FP_OFF(lpBase) <= nBytes)
	{
		UWORD newOffs = (FP_OFF(lpBase) + nBytes) & 0xFFFF;
		UWORD newSeg = FP_SEG(lpBase) + 0x1000;

		lpBase = MK_FP(newSeg, newOffs);
	} else lpBase += nBytes;

	return lpAllocated;
}
#endif

#ifdef I86
static VOID FAR *AlignParagraph(VOID FAR *lpPtr)
{
	ULONG lTemp;
	UWORD uSegVal;

	/* First, convert the segmented pointer to linear address	*/
	lTemp = FP_SEG(lpPtr);
	lTemp = (lTemp << 4) + FP_OFF(lpPtr);

	/* Next, round up the linear address to a paragraph boundary.	*/
	lTemp += 0x0f;
	lTemp &= 0xfffffff0l;

	/* Break it into segments.                                      */
	uSegVal = (UWORD)(lTemp >> 4);

	/* and return an adddress adjusted to the nearest paragraph     */
	/* boundary.                                                    */
	return MK_FP(uSegVal, 0);
}
#endif