void printString(char*);

void readAndPrint();

void readString(char*);

void handleInterrupt21(int , int , int , int);

void readSector(char* , int);

int mod(int ,int );

int div(int ,int );

void readFile(char*,char*);

void executeProgram (char* , int);

void terminateProgram();

void writeSector(char* , int);

void deleteFile(char*);

void writeFile(char* , char* , int);

int main()

{

makeInterrupt21();

interrupt(0x21,4,"shell\0",0x2000,0);

}

void printString(char* chars)

{

int i=0;

while(chars[i]!='\0')

{

char c = chars[i];

interrupt(0x10, 0xE*256+c, 0, 0, 0);

i++;

}

}

void readAndPrint()

{

while(1)

{

char x = interrupt(0x16, 0, 0, 0, 0);

interrupt(0x10, 0xE*256+x, 0, 0, 0);

}

}

void readString(char* array )

{

char* tmp = array;

int i = 0;

char x = 'm';

while(1)

{

if(x == 0xd)

break;

x = interrupt(0x16,0, 0, 0,0);

interrupt(0x10, 0xE*256+x, 0, 0, 0);

*array = x;

if(x == 0x8 && i!=0)

{

i-=2;

array-=2;

interrupt(0x10, 0xE*256+0, 0, 0, 0);

interrupt(0x10, 0xE*256+x, 0, 0, 0);

}

i++;

array++;

}

*array = 0xa;

array++;

*array = 0x0;

//printString("\n\0");

//printString(tmp);

}

void readSector(char* buffer, int sector){

int CL=mod (sector ,18 )+1;

int x=div(sector,18);

int DH =mod(x,2);

int CH=div(sector,36);

int CX=CH*256+CL;

int DX=DH*256+0;

int AX= 2*256 + 1;

interrupt(0x13, AX, buffer,CX, DX);

}

int div(int a ,int b){

int count =0;

if (a >= b)

while(a >= b){

a = a-b;

count ++;

}

return count;

}

int mod(int a ,int b){

int count =0;

if (a >= b)

while(a >= b){

a = a-b;

}

return a;

}

/*void handleInterrupt21(int ax, int bx, int cx, int dx){

printString("Hello mora\0");

}*/

void handleInterrupt21(int ax, int bx, int cx, int dx)

{

if(ax == 0)

printString(bx);

else if(ax == 1)

readString(bx);

else if(ax == 2)

readSector(bx, cx);

else if(ax == 3)

readFile(bx,cx);

else if(ax == 4)

executeProgram(bx, cx);

else if(ax == 5)

terminateProgram();

else if (ax == 6)

writeSector(bx,cx);

else if (ax == 7)

deleteFile(bx);

else if(ax == 8)

writeFile(bx,cx,dx);

else

printString("error\0");

}

void readFile(char* name, char* file){

int i=0;

int j=0;

int k=0;

int test=1;

char directory[512];

char fileName[6];

char* base = name;

int fileAddress = 0;

readSector(directory,2);

for(i=0;i<512;i++){

for(j=0;j<6;j++){

if(directory[i+j] != name[j]){

test = 0;

break;

}

}

if(test == 0){

//printString("3w\0");

i = i+31;

test =1;

}

else{

i+=6;

break;

}

}

if(test == 1){

for(k=0;k<26;k++){

if(directory[i] != 0x00){

readSector(fileAddress+file,directory[i]);

fileAddress = fileAddress+512;

i++;

}

else{

break;

}

}

}

}

void executeProgram (char* c , int seg)

{

char buffer[13312];

int i = 0;

readFile(c,buffer);

while(i < 13312)

{

putInMemory(seg , i , buffer[i]);

i++;

}

launchProgram(seg);

}

void terminateProgram()

{

char shell[6];

shell[0]='s';

shell[1]='h';

shell[2]='e';

shell[3]='l';

shell[4]='l';

shell[5]='\0';

interrupt(0x21,4,shell,0x2000,0);

while(1);

}

void writeSector(char* buffer, int sector)

{

int CL = mod (sector ,18 )+1;

int x = div(sector,18);

int DH = mod(x,2);

int CH = div(sector,36);

int CX = CH * 256 + CL;

int DX = DH * 256 + 0;

int AX = 3*256 + 1;

interrupt(0x13, AX, buffer,CX, DX);

}

void deleteFile(char* c)

{

char map[512];

char dir[512];

int i = 0;

char* base = c;

int flag = 1;

readSector(map , 1);

readSector(dir , 2);

while(i < 512)

{

int j = i;

c = base;

flag = 1;

while(*c != 0x0)

{

if(*c != dir[j])

{

flag = 0;

break;

}

j++;

c++;

}

if(flag == 1)

break;

i+=32;

}

dir[i] = 0x00;

i+=6;

while(dir[i] != 0x00)

{

map[dir[i]] = 0x00;

i++;

}

writeSector(map , 1);

writeSector(dir , 2);

}

void writeFile(char* name, char* buffer, int secNum)

{

int i = 0;

char map[512];

char directory[512];

int foundDirectory = 0;

int currentDirectoryIndex = 0;

int currentSectorIndex = 0;

int j = 0 ;

int foundSector = 0 ;

readSector(map,1);

readSector(directory,2);

while(i < 512){

if(directory[i] == 0x00){

foundDirectory = 1;

currentDirectoryIndex = i;

break;

}

i = i+32 ;

}

if(foundDirectory == 0){

printString("no free directory found ");

return ;

}

for (i = 0; i < 6; ++i)

{ if( *name != 0x00){

directory[currentDirectoryIndex] = *name ;

name++;

}

else

directory[currentDirectoryIndex] = 0x00 ;

currentDirectoryIndex++ ;

}

for ( i = 0; i < secNum; ++i)

{

/* code */

while(j < 512){

if (map[j] == 0x00)

{

foundSector = 1 ;

currentSectorIndex = j ;

map[currentSectorIndex] = 0xFF ;

j++;

break ;

}

j++;

}

if (foundSector == 0 )

{

printString("no free sectors found !");

return ;

}

directory[currentDirectoryIndex] = currentSectorIndex;

writeSector(buffer , currentSectorIndex);

buffer += 512 ;

foundSector = 0 ;

//currentSectorIndex++ ;

currentDirectoryIndex++ ;

}

while(mod(currentDirectoryIndex,32)){

directory[currentDirectoryIndex] = 0x00;

currentDirectoryIndex++;

}

writeSector(map ,1);

writeSector(directory, 2);

}