所以，当我在处理反汇编程序时，我注意到如果输出文件大小超过~16 KB，它会崩溃。程序的工作方式基本上是，如果输入文件具有某些十六进制/二进制值，它将输出不同的文本到输出文件。无论输入文件是什么都没关系，因为我尝试过很多不同的文件，并且它们都会产生相同的结果 - 如果输出文件太大则会崩溃。
以下是代码：
#include <stdio.h>
#include <string.h>
int main(int argc, char *argv[]) {
if (argc < 3){
printf("Not enough arguments!\nTo be executed as: .exe inputfile outputfile");
getch();
return (0);
}
FILE *InputFile, *OutputFile;
InputFile = fopen(argv[1], "rb"); // "r" = open for reading
if (InputFile == NULL){
printf("Can't open input file: %s\n", argv[1]);
getch();
return (0);
}
OutputFile = fopen(argv[2], "w+"); // "w+" = open for writing but delete old data
// data in file -> array
int i = 0;
unsigned int Instruction = 0;
unsigned int Instruction2 = 0;
unsigned int Instruction3 = 0;
unsigned int Instruction4 = 0;
int Index = 0;
int DataSize = 102400;
unsigned int temparray[DataSize/2];
unsigned int Filedata[DataSize];
for(i = 0;i < DataSize;i ++) {
Filedata[i] = 0xFE28; //Null the array
temparray[i/2] = 0xFE28; //Null the array
}
fread (&temparray,2,DataSize/2,InputFile); // get data to temp array
fclose(InputFile); /* close the file */
// move from temparray to normal array
Index = 0;
for(Index = 0;Index < DataSize/2;Index ++){
if(temparray[Index] == 0xFE28){
Index = DataSize +2;
} else{
Filedata[Index*2] = temparray[Index] & 0xFFFF;
Filedata[Index*2+1] = temparray[Index] >> 16 & 0xFFFF;
}
}
Index = 0;
// main code
for(Index = 0;Index < DataSize;){
if(Filedata[Index] == 0xFE28){
Index = DataSize +2;
} else{
Instruction = Filedata[Index];
Instruction2 = Filedata[Index+1];
Instruction3 = Filedata[Index+2];
Instruction4 = Filedata[Index+3];
Instruction = _32BInsto16LIns(Instruction);
Instruction2 = _32BInsto16LIns(Instruction2);
Instruction3 = _32BInsto16LIns(Instruction3);
Instruction4 = _32BInsto16LIns(Instruction4);
Index = ReadNextInstruction(Instruction,Instruction2,Instruction3,Instruction4,OutputFile,Index);
}
}
fclose(OutputFile); /* close the file */
return 0;
}
int _32BInsto16LIns(Input){
int temp = (Input &0xFF00) >> 8; // leave high byte
int temp2 = (Input &0x00FF) << 8;// leave only low byte
Input = temp + temp2; // combine rotated bytes
return(Input);
}
int ReadNextInstruction(Instruction,Instruction2,Instruction3,Instruction4,OutputFile,Index){
int temp1 = 0;
int temp2 = 0;
int temp3 = 0;
int temp4 = 0;
int temp5 = 0;
int tempI = 0;
if (Instruction == 0x4E75){ // rts
fprintf(OutputFile," rts ; return from subroutine\n");
Index ++;
return (Index);
} else if (Instruction == 0x4E77){ // rtr
fprintf(OutputFile," rtr ; return and restore\n");
Index ++;
return (Index);
} else if (Instruction == 0x4E73){ //rte
fprintf(OutputFile," rte ; return from interrupt\n");
Index ++;
return (Index);
} else if (Instruction == 0x4E71){ //nop
fprintf(OutputFile," nop ; no operation\n");
Index ++;
return (Index);
} else if (Instruction == 0x4E77){ // rtr
fprintf(OutputFile," rtr ; return and restore\n");
Index ++;
return (Index);
} else if (Instruction == 0x4AFC){ // illegal
fprintf(OutputFile," illegal ; cause a illegal instruction exception\n");
Index ++;
return (Index);
} else if (Instruction == 0x4E70){ // reset
fprintf(OutputFile," reset ; reset external devices\n");
Index ++;
return (Index);
} else if (Instruction == 0x4E76){ // trapv
fprintf(OutputFile," trapv ; trap on overflow\n");
Index ++;
return (Index);
} else if (Instruction == 0x4E72){ // stop #
fprintf(OutputFile," stop #$%X ; stop\n",Instruction2);
Index += 2;
return (Index);
}
tempI = Instruction &0xFFF0; // trap #
if (tempI == 0x4E40){
temp1 = Instruction & 0x000F;
fprintf(OutputFile," trap #$%X ; trap to interrupt #$%X\n", temp1,temp1);
Index ++;
return (Index);
}
tempI = Instruction & 0xFFF8; //unlk (An)
if (tempI == 0x4E58){
temp1 = Instruction & 0007;
fprintf(OutputFile," unlk A%X ; unlink stack frame\n",temp1);
Index ++;
return (Index);
}
tempI = Instruction & 0xFFF0; //link (An),#
if (tempI == 0x4E50){
temp1 = Instruction & 0007;
fprintf(OutputFile," link A%X,#$%X ; link stack frame at A%X\n",temp1,Instruction2,temp1);
Index += 2;
return (Index);
}
tempI = Instruction & 0xFFF0;
if (tempI == 0x4840){ // swap Dn
temp1 = Instruction & 0007;
fprintf(OutputFile," swap D%X ; swap words on D%X\n",temp1,temp1);
Index ++;
return (Index);
}
tempI = Instruction & 0xFF00; //jmp/jsr
if (tempI == 0x4E00){
// select between jmp and jsr
temp1 = (Instruction & 0x00C0) >> 6;
if (temp1 == 3){
fprintf(OutputFile," jmp ");
} else if(temp1 == 2){
fprintf(OutputFile," jsr ");
} else { // if neither, is not valid jmp/jsr instruction
fprintf(OutputFile," dc.w $%X\n", Instruction);
Index ++;
return (Index);
}
// fill out the rest of the instruction
temp3 = (Instruction & 0x0038) >> 3;
temp2 = (Instruction & 0x0007);
if (temp3 == 2){ // if jxx an
fprintf(OutputFile,"(A%X) \n",temp2);
Index ++;
return (Index);
} else if (temp3 == 7) {
if (temp2 == 0){ // if jxx $.w
fprintf(OutputFile,"$%X.w \n",Instruction2);
Index += 2;
return (Index);
} else if (temp2 == 1){ // if jxx $.l
fprintf(OutputFile,"$%X%X.l \n",Instruction2,Instruction3);
Index += 3;
return (Index);
} else if (temp2 == 3) { // if jxx (Dn,pc)
temp4 = (Instruction2 + 6) & 0x00FF;
if (temp4 == 0){
fprintf(OutputFile,"(D%X,PC) \n",(Instruction2 >> 12) & 0x7);
} else {
fprintf(OutputFile,"$%X(PC,D%X) \n",temp4,(Instruction2 >> 12) & 0x7);
}
Index += 2;
return (Index);
} else {
fprintf(OutputFile," dc.w $%X\n", Instruction);
Index ++;
return (Index);
}
} else {
fprintf(OutputFile," dc.w $%X\n", Instruction);
Index ++;
return (Index);
}
Index += 2;
return (Index);
}
tempI = Instruction & 0xF000; // bxx
if (tempI == 0x6000){
fprintf(OutputFile," b");
temp1 = (Instruction & 0x0F00) >> 8; // figure the right extention
char* temp_extentionarr[15] = { "ra", "rs", "hi", "ls", "cc", "cs", "ne", "eq", "vc", "vs", "pl", "mi", "ge", "lt", "gt", "le" };
fprintf(OutputFile,"%s",temp_extentionarr[temp1]); // write correct extension
temp2 = (Instruction & 0x00FF) + 2; // calculate the lenght
if(temp2 == 2){ //bxx.w
fprintf(OutputFile,".w *+$%X\n",Instruction2 + 2);
Index += 2;
return (Index);
} else { // bxx.s
fprintf(OutputFile,".s *+$%X\n",temp2);
Index ++;
return (Index);
}
} else {
fprintf(OutputFile," dc.w $%X\n", Instruction);
Index ++;
return (Index);
}
}
另外，我在使用fread（）命令时遇到了一些问题，当我尝试指定它只为每个数组位置写入2个字节时，它确实是4.我做错了什么？： fread（＆amp; temparray，2，DataSize / 2，InputFile）;