/* sun.c - Read SUN style partition tables.  */
/*
 *  VasEBoot  --  GRand Unified Bootloader
 *  Copyright (C) 2002,2005,2006,2007  Free Software Foundation, Inc.
 *
 *  VasEBoot 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 3 of the License, or
 *  (at your option) any later version.
 *
 *  VasEBoot 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 VasEBoot.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <VasEBoot/partition.h>
#include <VasEBoot/disk.h>
#include <VasEBoot/mm.h>
#include <VasEBoot/misc.h>
#include <VasEBoot/dl.h>
#include <VasEBoot/symbol.h>
#include <VasEBoot/types.h>
#include <VasEBoot/err.h>

VasEBoot_MOD_LICENSE ("GPLv3+");

#define VasEBoot_PARTMAP_SUN_MAGIC 0xDABE
#define VasEBoot_PARTMAP_SUN_MAX_PARTS 8
#define VasEBoot_PARTMAP_SUN_WHOLE_DISK_ID 0x05

struct VasEBoot_sun_partition_info
{
  VasEBoot_uint8_t spare1;
  VasEBoot_uint8_t id;
  VasEBoot_uint8_t spare2;
  VasEBoot_uint8_t flags;
} VasEBoot_PACKED;

struct VasEBoot_sun_partition_descriptor
{
  VasEBoot_uint32_t start_cylinder;
  VasEBoot_uint32_t num_sectors;
} VasEBoot_PACKED;

struct VasEBoot_sun_block
{
  VasEBoot_uint8_t  info[128];      /* Informative text string.  */
  VasEBoot_uint8_t  spare0[14];
  struct VasEBoot_sun_partition_info infos[8];
  VasEBoot_uint8_t  spare1[246];    /* Boot information etc.  */
  VasEBoot_uint16_t  rspeed;        /* Disk rotational speed.  */
  VasEBoot_uint16_t  pcylcount;     /* Physical cylinder count.  */
  VasEBoot_uint16_t  sparecyl;      /* extra sects per cylinder.  */
  VasEBoot_uint8_t  spare2[4];      /* More magic...  */
  VasEBoot_uint16_t  ilfact;        /* Interleave factor.  */
  VasEBoot_uint16_t  ncyl;          /* Data cylinder count.  */
  VasEBoot_uint16_t  nacyl;         /* Alt. cylinder count.  */
  VasEBoot_uint16_t  ntrks;         /* Tracks per cylinder.  */
  VasEBoot_uint16_t  nsect;         /* Sectors per track.  */
  VasEBoot_uint8_t  spare3[4];      /* Even more magic...  */
  struct VasEBoot_sun_partition_descriptor partitions[8];
  VasEBoot_uint16_t  magic;         /* Magic number.  */
  VasEBoot_uint16_t  csum;          /* Label xor'd checksum.  */
} VasEBoot_PACKED;

static struct VasEBoot_partition_map VasEBoot_sun_partition_map;

/* Verify checksum (true=ok).  */
static int
VasEBoot_sun_is_valid (VasEBoot_uint16_t *label)
{
  VasEBoot_uint16_t *pos;
  VasEBoot_uint16_t sum = 0;

  for (pos = label;
       pos < (label + sizeof (struct VasEBoot_sun_block) / 2);
       pos++)
    sum ^= *pos;

  return ! sum;
}

static VasEBoot_err_t
sun_partition_map_iterate (VasEBoot_disk_t disk,
			   VasEBoot_partition_iterate_hook_t hook, void *hook_data)
{
  struct VasEBoot_partition p;
  union
  {
    struct VasEBoot_sun_block sun_block;
    VasEBoot_uint16_t raw[0];
  } block;
  int partnum;
  VasEBoot_err_t err;

  p.partmap = &VasEBoot_sun_partition_map;
  err = VasEBoot_disk_read (disk, 0, 0, sizeof (struct VasEBoot_sun_block),
			&block);
  if (err)
    return err;

  if (VasEBoot_PARTMAP_SUN_MAGIC != VasEBoot_be_to_cpu16 (block.sun_block.magic))
    return VasEBoot_error (VasEBoot_ERR_BAD_PART_TABLE, "not a sun partition table");

  if (! VasEBoot_sun_is_valid (block.raw))
      return VasEBoot_error (VasEBoot_ERR_BAD_PART_TABLE, "invalid checksum");
  
  /* Maybe another error value would be better, because partition
     table _is_ recognized but invalid.  */
  for (partnum = 0; partnum < VasEBoot_PARTMAP_SUN_MAX_PARTS; partnum++)
    {
      struct VasEBoot_sun_partition_descriptor *desc;

      if (block.sun_block.infos[partnum].id == 0
	  || block.sun_block.infos[partnum].id == VasEBoot_PARTMAP_SUN_WHOLE_DISK_ID)
	continue;

      desc = &block.sun_block.partitions[partnum];
      p.start = ((VasEBoot_uint64_t) VasEBoot_be_to_cpu32 (desc->start_cylinder)
		  * VasEBoot_be_to_cpu16 (block.sun_block.ntrks)
		  * VasEBoot_be_to_cpu16 (block.sun_block.nsect));
      p.len = VasEBoot_be_to_cpu32 (desc->num_sectors);
      p.number = p.index = partnum;
      if (p.len)
	{
	  if (hook (disk, &p, hook_data))
	    partnum = VasEBoot_PARTMAP_SUN_MAX_PARTS;
	}
    }

  return VasEBoot_errno;
}

/* Partition map type.  */
static struct VasEBoot_partition_map VasEBoot_sun_partition_map =
  {
    .name = "sun",
    .iterate = sun_partition_map_iterate,
  };

VasEBoot_MOD_INIT(part_sun)
{
  VasEBoot_partition_map_register (&VasEBoot_sun_partition_map);
}

VasEBoot_MOD_FINI(part_sun)
{
  VasEBoot_partition_map_unregister (&VasEBoot_sun_partition_map);
}