Board.KolibriOS.org

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#include <stdio.h>
#include <conio.h>
#include <malloc.h>
#include <dos.h>
//#include "sysp.h"

char *buf, *fat;

int getN(char *buf, unsigned byte1, unsigned size)
{
  int r = 0;
  for(int i = byte1 + size - 1; i >= byte1; i--)
  {
    r *=256;
    r += buf[i];
  }
  return r;
}

void readSect(char *buf, unsigned sect1, unsigned num)
{
  REGS rs;
  SREGS ss;
  rs.x.dx = sect1;
  rs.x.cx = num;
  rs.x.bx = FP_OFF(buf);
  rs.x.ax &= 0;//Number of drive
  ss.ds = FP_SEG(buf);
  int86x(0x25, &rs, &rs, &ss);
}

  unsigned int wSectSize, wResSects, fatSect, wFatSects, bFatCnt, RootSect,
  wRootEntries, bClustSects, DataSect;

unsigned int nextCluster(int k)
{
  unsigned int start = k * 3 / 2, r = 0;
  r = fat[start];
  start++;
  r += (unsigned int)fat[start] * 256;
  if(k % 2 == 0)
    return (r & 0xFFF);
  else
    return (r >> 4);
}

int main()
{
  char c;
  clrscr();
  buf = (char *)calloc(512, 1);
  readSect(buf, 0, 1);

  wSectSize = getN(buf, 0xB, 2);
  fatSect = wResSects = getN(buf, 0xE, 2);
  wFatSects = getN(buf, 0x16, 2);
  bFatCnt = getN(buf, 0x10, 1);
  RootSect = fatSect + wFatSects * bFatCnt;
  wRootEntries = getN(buf, 0x11, 2);
  bClustSects = getN(buf, 0xD, 1);
  DataSect = RootSect + wRootEntries * 32 / wSectSize;

  printf("wFatSects = %d\n", wFatSects);
  printf("Reserved = %d\nFAT begin = %d\nFATSize = %d\nFATCount = %d\n",
  wResSects, fatSect, wFatSects, bFatCnt);
  printf("RootSector = %d\nRootSize = %d\nSector Size = %d\n",
  RootSect, wRootEntries, wSectSize);
  free(buf);
  fat = (char *)calloc(sizeof(char), wFatSects * wSectSize);
  readSect(fat, fatSect, wFatSects * bClustSects);

  for(unsigned int i = 0; i < wFatSects * wSectSize * 2 / 3; i++)
  {
    unsigned int r = nextCluster(i);
    if(i % 20 == 0)
    {
      clrscr();
      printf("Cluster   | Value \n");
    }
    printf("%-9X        %-9X\n", i, r);
    if(i % 20 == 19)
    {
      c = getch();
      if(c == 'q')
        return 0;
    }
  }/**/
  free(fat);
  scanf("%c", c);
  return 0;
}