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/*

 * Project: S.Ha.R.K.

 *

 * Coordinators:

 *   Giorgio Buttazzo    <giorgio@sssup.it>

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *

 * Authors     :

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *   Massimiliano Giorgi <massy@gandalf.sssup.it>

 *   Luca Abeni          <luca@gandalf.sssup.it>

 *   (see the web pages for full authors list)

 *

 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)

 *

 * http://www.sssup.it

 * http://retis.sssup.it

 * http://shark.sssup.it

 */

/***************************************

  CVS :        $Id: lodsk.c,v 1.1.1.1 2002-03-29 14:12:49 pj Exp $

  Revision:    $Revision: 1.1.1.1 $

  Last update: $Date: 2002-03-29 14:12:49 $

  This module is used by block device sub-system to scan a physical

  hard disk to find logical layout (partition scheme).

***************************************/

/*

 * Copyright (C) 1999 Massimiliano Giorgi

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 */

#include "glue.h"

#include "bdev.h"

#include "sysind.h"

#include "lodsk.h"

/*+ Log Level used to report an error +*/

#define LODSKERRLOG KERN_ERR

/*+ Log level used to inform +*/

#define LODSKLOG    KERN_NOTICE

/*+ An aligned buffer for data I/O +*/

static __uint8_t  buffer[512] __attribute__ ((aligned(4)));

/*++++++++++++++++++++++++++++++++++++++

  This function convert a physical partion structure to a partition

  structure (the difference is that the physical partition structure

  has a "strange" layout and must be parsed to find actually values that

  are saved into a partition structure).

  struct phpartition *ph

    physical partition to parse

  struct partition *lo

    values are stored into this structure

  ++++++++++++++++++++++++++++++++++++++*/

static void partph2lo(struct phpartition *ph,struct partition *lo)

{

  lo->boot_ind=((ph->boot_ind&0x80)?1:0);

  lo->sys_ind=ph->sys_ind;

  lo->rel_sect=ph->rel_sect;

  lo->nr_sects=ph->nr_sects;

  /**/

  lo->st_head=ph->st_h;

  lo->st_sect=ph->st_s&0x3f;

  lo->st_cyl=(__uint16_t)ph->st_c|(((__uint16_t)ph->st_s&0xc0)<<2);

  lo->en_head=ph->st_h;

  lo->en_sect=ph->en_s&0x3f;

  lo->en_cyl=(__uint16_t)ph->en_c|(((__uint16_t)ph->en_s&0xc0)<<2);

}

/*++++++++++++++++++++++++++++++++++++++

  Find if a partition is an extended partition.

  #define is_extended_partition

    return 0 if no, other value if yes

  sys_ind

    "system indicator" for that partition

  ++++++++++++++++++++++++++++++++++++++*/

#define is_extended_partition(sys_ind) (   \

  (sys_ind) == DOS_EXTENDED_PARTITION ||   \

  (sys_ind) == WIN98_EXTENDED_PARTITION || \

  (sys_ind) == LINUX_EXTENDED_PARTITION    \

)

/*++++++++++++++++++++++++++++++++++++++

  Scan recursiverly an extended partition to find other partition (this

  function suppose an IBM PC hard disk architecture).

  When a new partition is found the callback function is called.

  int extended_partition

    return 0 on success, other value on error

  char *lname

    it is the name of the physical disk; for informational purpose only

    (for example "hda").

  __dev_t device

    it's the device to scan

  lodsk_callback_func func

    it's the callback function to call when a new partition is found

  void *data

    this is opaque data passed to the callback function

  __blkcnt_t psect

    is the starting block (sector) number for this extended partition

  __blkcnt_t psize

    is the size in blocks of this extended partition

  int showinfo

    show information with printk()

  ++++++++++++++++++++++++++++++++++++++*/

/* this routine is from Linux 2.2.9 (modificated to run into S.Ha.R.K.) */

static int extended_partition(char *lname, __dev_t device,

                              lodsk_callback_func func, void *data,

                              __blkcnt_t psect, __blkcnt_t psize,

                              char *infobuffer, int nextid)

{

  char name[MAXLODSKNAME];

  struct phpartition *ppar;

  struct partition lpar;

  struct lodskinfo info;

  __blkcnt_t stpsect=psect;

  int ret;

  int i;

  int counter=5;

  int first=1;

  //if (phdsk_sectorsize(pdisk)!=512) return -1;

  for (;;) {

    //cprintf("reading block %li\n",(long)psect);

    ret=bdev_read(device,psect,buffer);

    if (ret) return -1;

    //cprintf("read block %li\n",(long)psect);

    if (*(__uint16_t*)(buffer+0x1fe)!=MSDOS_LABEL_MAGIC) return -1;

    //cprintf("ok sector\n");

    ppar=(struct phpartition*)(buffer+0x1be);

    /*

     * Usually, the first entry is the real data partition,

     * the 2nd entry is the next extended partition, or empty,

     * and the 3rd and 4th entries are unused.

     * However, DRDOS sometimes has the extended partition as

     * the first entry (when the data partition is empty),

     * and OS/2 seems to use all four entries.

     */

    /*

     * First process the data partition(s)

     */

    for (i=0; i<4; i++, ppar++) {

      partph2lo(ppar,&lpar);

      /*

        cprintf("-- %i --\n",i+x);

        cprintf("c: %4i h: %4i s: %4i\n",lpar.st_cyl,lpar.st_head,lpar.st_sect);

        cprintf("c: %4i h: %4i s: %4i\n",lpar.en_cyl,lpar.en_head,lpar.en_sect);

        cprintf("sys: %02x relsec: %li  num sect: %li\n",

        lpar.sys_ind,lpar.rel_sect,lpar.nr_sects);

        */

      if (!lpar.nr_sects || is_extended_partition(lpar.sys_ind))

        continue;

      /* Check the 3rd and 4th entries -

         these sometimes contain random garbage */

      if (i >= 2

          && lpar.rel_sect + lpar.nr_sects > psize

          && (psect + lpar.rel_sect < psect ||

              psect + lpar.rel_sect + lpar.nr_sects >

              psect + psize))

        continue;

      sprintf(name,"%s%i ",lname,counter++);

      info.fs_ind=lpar.sys_ind;

      info.start=psect+lpar.rel_sect;

      info.size=lpar.nr_sects;

      ret=func(nextid++,&info,data);

      if (infobuffer!=NULL&&first) strcat(infobuffer,"< ");

      first=0;

      if (infobuffer) strcat(infobuffer,name);

    }

    ppar=(struct phpartition*)(buffer+0x1be);

    /*

     * Next, process the (first) extended partition, if present.

     * (So far, there seems to be no reason to make

     *  extended_partition()  recursive and allow a tree

     *  of extended partitions.)

     * It should be a link to the next logical partition.

     * Create a minor for this just long enough to get the next

     * partition table.  The minor will be reused for the next

     * data partition.

     */

    for (i=0; i<4; i++, ppar++)

      if(ppar->nr_sects && is_extended_partition(ppar->sys_ind))

        break;

    if (i == 4)

      break;     /* nothing left to do, go to the end*/

    psect=stpsect+ppar->rel_sect;

    psize=ppar->nr_sects;

  }

  if (infobuffer!=NULL&&!first) strcat(infobuffer,"> ");

  return nextid;

}

//extern int ide_check_geometry(int pdisk, __uint8_t *buffer);

/*++++++++++++++++++++++++++++++++++++++

  This function is called to scan a physical hard disk to find its logical

  structure (IBM PC hard disk harchitecture is supposed).

  int msdos_partition

    return 0 on success, other value on error

  char *lname

    name to use if information is shown (for example "hdc")

  __dev_t device

    device to scan

  lodsk_callback_func func

    callback function to call when a partition is found

  void *data

    opaque data passed to the callback function

  int showinfo

    is true if informations will be displayed

  ++++++++++++++++++++++++++++++++++++++*/

/* this routine is from Linux 2.2.9 (modificated to run into S.Ha.R.K.) */

static int ibmpc_arch_scan(char *lname, __dev_t device,

                           lodsk_callback_func func,

                           void *data, char *infobuffer)

{

  struct lodskinfo info;

  char name[MAXLODSKNAME];

  struct phpartition *ppar;

  struct partition lpar;

  int i;

  int ret;

  int nextid;

  ret=bdev_read(device,0,buffer);

  if (ret) {

    cprintf("XXXXXXXXXXXXXXXX");

    return -1;

  }

  //if (phdsk_sectorsize(pdisk)!=512) return -1;

  if (*(__uint16_t*)(buffer+0x1fe)!=MSDOS_LABEL_MAGIC) return -1;

  ppar=(struct phpartition*)(buffer+0x1be);

  nextid=5;

  for (i=0;i<4;i++,ppar+=1) {

    partph2lo(ppar,&lpar);

    /*

    cprintf("-- %i --\n",i);

    cprintf("c: %4i h: %4i s: %4i\n",lpar.st_cyl,lpar.st_head,lpar.st_sect);

    cprintf("c: %4i h: %4i s: %4i\n",lpar.en_cyl,lpar.en_head,lpar.en_sect);

    cprintf("sys: %02x relsec: %li  num sect: %li\n",

              lpar.sys_ind,lpar.rel_sect,lpar.nr_sects);

    */

    /*

    if (phdsk[pdisk].ide_check_geom&&i==0) {

      ide_check_geometry(pdisk,buffer);

    }

    */

    if (!lpar.nr_sects) continue;

    if (is_extended_partition(lpar.sys_ind)) {

      nextid=extended_partition(lname,device,func,data,

                         lpar.rel_sect,lpar.nr_sects,infobuffer,nextid);

      if (nextid<0) return -1;

    } else {

      sprintf(name,"%s%i ",lname,i+1);

      info.fs_ind=lpar.sys_ind;

      info.start=lpar.rel_sect;

      info.size=lpar.nr_sects;

      ret=func(i+1,&info,data);      

      if (infobuffer) strcat(infobuffer,name);

      if (ret) return 0;

    }    

  }

  return 0;

}

/*++++++++++++++++++++++++++++++++++++++

  This function scan a physical hard disk for logical structure; actually

  only IBM PC hard disk architecture is recognized.

  int lodsk_scan

    return 0 on success, other value on error

  __dev_t device

    device to scan

  lodsk_callback_func func

    callback function to call when a new partition is found

  void *data

    opaque data passed to the callback function

  int showinfo

    if information must be displayed

  char *lname

    logical name, for information only (example "hda")

  ++++++++++++++++++++++++++++++++++++++*/

int lodsk_scan(__dev_t device, lodsk_callback_func func,

               void *data, int showinfo, char *lname)

{

  char buffer[1024]; /* DANGER!!! */

  int ret;

  if (showinfo) sprintf(buffer,"%s: ",lname);

  ret=ibmpc_arch_scan(lname,device,func,data,showinfo?buffer:NULL);

  if (showinfo) printk(KERN_INFO "%s",buffer);

  return ret;

}