dbgdata.c

简单的虚拟机

#include <stdio.h>
#include <stdlib.h>
#include "dbgdata.h"

void printHeaderRec(struct HeaderRec* hptr)
{
	if(hptr->magic != SIGNATURE)
	{
		printf("DOS magic number doesn't match!\n");
		exit(1);
	}
	printf("DOS Header Magic Number:\t\t%04X \"%c%c\"\n", hptr->magic, hptr->magic & 0x00FF, (hptr->magic & 0xFF00) >> 8);
	/* print Bytes on last page of file */
	printf("Bytes on last page of file:     \t%04X\n", hptr->lpbytes);
	/* print Pages in file */
	printf("Pages in file:                  \t%04X\n", hptr->pages);
	/* print Relocations */
	printf("Relocations:                    \t%04X\n", hptr->relocs);
	/* print Size of header in paragraphs */
	printf("Size of header in paragraphs:    \t%04X\n", hptr->hdsize);
	/* print Minimum extra paragraphs needed */
	printf("Minimun extra paragraphs needed: \t%04X\n", hptr->minparas);
	/* print Maxmum extra paragraphs needed */
	printf("Maximum extra paragraphs needed: \t%04X\n", hptr->maxparas);
	/* print Initial (relative) SS value */
	printf("Initial (relative) SS:           \t%04X\n", hptr->ss);
	/* print  Initial SP value */
	printf("Initial SP:                      \t%04X\n", hptr->sp);
	/* print Checksum */
	printf("Checksum:                        \t%04X\n", hptr->chksum);
	/* print Initial IP value */
	printf("Initial IP value:                \t%04X\n", hptr->ip);
	/* print Initial (relative) CS value */
	printf("Initial (relative) CS value:     \t%04X\n", hptr->cs);
	/* print File Address of relocation table */
	printf("File Address of relocation table: \t%04X\n", hptr->roffset);
	/* print Overlay number */
	printf("Overlay number:\t%04X\n", hptr->overlay);
}

bool readDebugData(struct HeaderRec* hptr,struct RelocRec* rptr,FILE* fptr)
{
	int i;
	fseek(fptr, 0, SEEK_SET);
	fread(hptr, sizeof(struct HeaderRec), 1, fptr);
	if(feof(fptr)||ferror(fptr))
	{
		printf("readDebugData(): error reading header record!\n");
		return false;
	}
	printf("==================================================\n");
	printf("header record:\n");
	printHeaderRec(hptr);
	printf("==================================================\n");

	printf("relocation table:\n");
	if(hptr->relocs<=0)
	{
		printf("readDebugData(): no relocation item\n");
		rptr=NULL;
	}
	else
	{
		if(!(rptr=(struct RelocRec*)malloc(hptr->relocs*sizeof(struct RelocRec))))
		{
			printf("readDebugData(): memory allocation error!\n");
			return false;
		}
		fseek(fptr, hptr->roffset,SEEK_SET);
		fread(rptr,sizeof(struct RelocRec),hptr->relocs,fptr);
		if(feof(fptr)||ferror(fptr))
		{
			printf("readDebugData(): error reading relocation record!\n");
			free(rptr);
			return false;
		}
		for(i=0;i<hptr->relocs;i++)
		{
			printf("rrec[%d].offset=%X\n",i,rptr[i].offset);
			printf("rrec[%d].segmet=%x\n",i,rptr[i].segment);
		}
	}
	printf("==================================================\n");
	return true;
}
/*void print_reloc(reloc* rlc, int relocations);*/