/* With thanks to http://www.datarescue.com/laboratory/partition.htm */

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "m.h"

struct partition {
  unsigned char bootable;             /* 0 or 0x80 */
  unsigned char begin_head;
  unsigned char begin_chs[2];
  unsigned char sys_type;
  unsigned char end_chs[2]; 
  unsigned char start_sect[4];    /* starting sector counting from 0 */
  unsigned char nr_sects[4];              /* nr of sectors in partition */
};  

int fs_idx(int n)
{
  int i;

  for (i=0; i386_sys_types[i].name!=NULL; i++) {
    if (i386_sys_types[i].type==n) {
      return i;
    }
  }
  return -1;
}

void show_partition_layout(struct partition p)
{
  int cyl=0;
  int sect=0;

  printf("        Tag        : 0x%02x\n", p.sys_type);
  cyl=(p.begin_chs[0]<<2) + (p.begin_chs[1]>>6);
  sect=p.begin_chs[1] >> 1;
  printf("        Start CHS : %d / %d / %d\n", cyl, p.begin_head, sect);
  printf("        Size       : 0x%02x%02x%02x%02x\n", p.nr_sects[0], p.nr_sects[1], p.nr_sects[2], p.nr_sects[3]);
}

void read_partitions(char *dev) {
  int fd;
  struct partition p;
  int i;
  char *c;
  

  /* Open the device Read-Only (I don't really know what I'm doing!) */
  fd=open(dev, O_RDONLY);
  if (fd<0) {
	  printf("Cannot open %s for reading\n", dev);
	  exit(1);
  }

  /* Skip bootblock */
  if (lseek(fd, 0x1BE, 0)==-1) {
      printf("Error skipping bootblock: %s (%d)\n", strerror(errno), errno);
      exit(1);
  }
  for (i=1; i<=4; i++) { 
	    if (read(fd, &p, 16)==-1) {
                 printf("Error %d reading partition: %s\n", errno, strerror(errno)); close(fd); free(c); exit(1); 
            }
      	    printf("%s%d : %s", dev, i, i386_sys_types[fs_idx(p.sys_type)].name);
	    if (p.bootable==0x80) printf(" *\n"); else printf("\n");
	    /* Temporary hack to see what we've got ... */
	    show_partition_layout(p);
  }
  close(fd);
}

int main()
{
   /* Let's be crude ... just look at hda and hdb for now! */
	read_partitions("/dev/hda");
	read_partitions("/dev/hdb");
  /* If we get this far, we didn't *detect* any problems! */
  return 0;
}