/*
 * lib/scheme/eesox.c
 *
 * Partition backend for Eesox SCSI partitioning scheme on the
 * Acorn machines.
 *
 * Copyright (C) 1998 Russell King
 */
#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include "util/debug.h"
#include "util/error.h"
#include "util/types.h"
#include "part/part.h"
#include "part/utils.h"

#define EESOX_SECTOR_SIZE	512
#define EESOX_PART_SECTOR	7
#define EESOX_NR_PARTITIONS	8

#define NOSAVE_POWERTEC

typedef struct {
  char magic[6];
  char discname[10];
  u32 start;
  u32 unused6;
  u32 unused7;
  u32 unused8;
} ep_t;

typedef union {
  ep_t ep[EESOX_NR_PARTITIONS];
  u8 sector[EESOX_SECTOR_SIZE];
} eesox_psect_t;

static const char eesox_name[] = {
  'N', 'e', 'i', 'l', ' ',
  'C', 'r', 'i', 't', 'c', 'h', 'e', 'l', 'l', ' ', ' '
};

/* Prototype: u_int eesox_detect(part_t *part)
 * Function : detect a drive partitioned with an ICS IDE table
 * Params   : part - partitionable device
 * Returns  : FALSE if not detected
 */
static u_int
eesox_detect(part_t *part)
{
  eesox_psect_t sector;
  u_int ret = 0;
  dbg_printf("eesox_detect()");
  dbg_level_up();

  assert(part != NULL);

  do {
    u_int i;
    if (blkio_setblocksize(part->blkio, EESOX_SECTOR_SIZE) != EESOX_SECTOR_SIZE)
      break;

    if (blkio_read(part->blkio, sector.sector, EESOX_PART_SECTOR, 1) != 1)
      break;

    for (i = 0; i < EESOX_SECTOR_SIZE; i++)
      sector.sector[i] ^= eesox_name[i & 15];

    if (memcmp(sector.sector, "Eesox", 6) == 0)
      ret = 1;
  } while (0);

  dbg_level_down();
  dbg_printf("ret%s detected", ret ? "" : " not");
  return ret;
}

/* Prototype: u_int eesox_readinfo(part_t *part)
 * Function : read all partition information from the drive
 * Params   : part - partitionable device
 * Returns  : FALSE on error
 */
static u_int
eesox_readinfo(part_t *part)
{
  u_int ret = 0;

  dbg_printf("eesox_readinfo()");
  dbg_level_up();

  assert(part != NULL);

  do {
    eesox_psect_t sector;
    partinfo_i_t pinfo;
    u_int part_no, i;

    if (blkio_read(part->blkio, sector.sector, EESOX_PART_SECTOR, 1) != 1)
      break;

    for (i = 0; i < EESOX_SECTOR_SIZE; i++)
      sector.sector[i] ^= eesox_name[i & 15];

    ret = 1;

    for (part_no = 0; part_no < EESOX_NR_PARTITIONS; part_no++)
      if (memcmp(sector.ep[part_no].magic, "Eesox", 6) == 0) {
        pinfo.info.chs_valid     = 0;
        pinfo.info.blk_start	 = sector.ep[part_no].start;
        pinfo.info.blk_end	 = sector.ep[part_no].start + 1;
        pinfo.info.kern_part_no	 = part_no + 1;
        pinfo.info.type = ptyp_filecore;
dbg_memdump(&sector.ep[part_no], sizeof(sector.ep[part_no]));
        if (!part_add(part, part_no + 1, &pinfo)) {
          ret = 0;
          break;
        }

        /* should we check the filecore boot sector? */
      }
  } while (0);

  dbg_level_down();
  dbg_printf("ret %s", ret ? "ok" : "error");

  return ret;
}

/* Prototype: u_int eesox_writeinfo(part_t *part)
 * Function : write all partition information back to the drive
 * Params   : part - partitionable device
 * Returns  : FALSE on error
 */
static u_int
eesox_writeinfo(part_t *part)
{
  u_int ret = 0;

  dbg_printf("eesox_writeinfo()");
  dbg_level_up();

  assert(part != NULL);
  assert(part->nr_partitions <= EESOX_NR_PARTITIONS);

  set_error("EESOX partition information cannot be saved with this build");

  dbg_level_down();
  dbg_printf("ret %s", ret ? "ok" : "error");

  return ret;
}

/* Prototype: u_int eesox_allocate(part_t *part, partinfo_t *pnew)
 * Function : allocate a partition entry number and a kernel
 *            partition number for a new partition
 * Params   : part - partitionable device
 * Returns  : partition number, or PARN_ERROR on error
 */
static u_int
eesox_allocate(part_t *part, partinfo_t *pnew)
{
  u_int parn = PARN_ERROR;
  assert(part != NULL);

  dbg_printf("eesox_allocate()");
  dbg_level_up();

  dbg_level_down();
  dbg_printf("ret %d", parn);

  return parn;
}

/* Prototype: u_int eesox_validate_change(part_t *part, u_int parn,
 *                                         const partinfo_t *pold, const partinfo_t *pnew)
 * Function : validate changes made to a partition
 * Params   : part - partitionable device
 *          : parn - partition number
 *          : pold - old partition information
 *          : pnew - new partition information
 * Returns  : FALSE if we reject the change
 */
static u_int
eesox_validate_change(part_t *part, u_int parn, const partinfo_t *pold, const partinfo_t *pnew)
{
  u_int ret = 0;

  dbg_printf("eesox_validate_change(parn=%d)", parn);
  dbg_level_up();

  dbg_level_down();
  dbg_printf("ret %svalid", ret ? "" : "in");

  return ret;
}

/* Prototype: u_int eesox_validate_creation(part_t *part, u_int parn,
 *                                           const partinfo_t *pold, const partinfo_t *pnew)
 * Function : validate changes made to a partition
 * Params   : part - partitionable device
 *          : parn - partition number
 *          : pold - old partition information (NULL if none)
 *          : pnew - new partition information
 * Returns  : FALSE if we reject the creation
 */
static u_int
eesox_validate_creation(part_t *part, u_int parn, const partinfo_t *pold, const partinfo_t *pnew)
{
  u_int ret = 0;

  dbg_printf("eesox_validate_creation(parn=%d)", parn);
  dbg_level_up();

  assert(part != NULL);
  assert(parn < part->nr_partitions);

  dbg_level_down();
  dbg_printf("ret %svalid", ret ? "" : "in");

  return ret;
}

/* Prototype: u_int eesox_validate_deletion(part_t *part, u_int parn, const partinfo_t *pold)
 * Function : validate a deletion of a partition
 * Params   : part - partitionable device
 *          : parn - partition number
 *          : pold - old partition information
 * Returns  : FALSE if we reject the deletion
 */
static u_int
eesox_validate_deletion(part_t *part, u_int parn, const partinfo_t *pold)
{
  u_int ret = 0;

  dbg_printf("eesox_validate_deletion(parn=%d)", parn);
  dbg_level_up();

  assert(part != NULL);
  assert(parn < part->nr_partitions);

  dbg_level_down();
  dbg_printf("ret %svalid", ret ? "" : "in");

  return ret;
}

/* Prototype: u_int eesox_validate_partno(part_t *part, u_int parn)
 * Function : validate a partition number
 * Params   : part - partitionable device
 *          : parn - partition number
 * Returns  : FALSE if we reject the partition number
 */
static u_int
eesox_validate_partno(part_t *part, u_int parn)
{
  u_int ret = 0;

  assert(part != NULL);

  dbg_printf("eesox_validate_partno(parn=%d)", parn);
  dbg_level_up();

  dbg_level_down();
  dbg_printf("ret %svalid", ret ? "" : "in");

  return ret;
}

/* Prototype: ptyp_t eesox_nexttype(part_t *part, u_int parn, ptyp_t current, int dir)
 * Purpose  : return next valid partition type for an entry
 * Params   : part    - partitionable device
 *          : parn    - partition number
 *          : current - currently selected partition type
 *          : dir     - next/previous flag
 * Returns  : next valid partition type
 */
static ptyp_t
eesox_nexttype(part_t *part, u_int parn, ptyp_t current, int dir)
{
  ptyp_t ptype = current;
  dbg_printf("eesox_nexttype(parn=%d, current=0x%X, %s)", parn, current,
	     dir > 0 ? "next" : dir < 0 ? "previous" : "???");
  dbg_level_up();
  assert(part != NULL);
  assert(parn < part->nr_partitions);

  dbg_level_down();
  dbg_printf("ret 0x%X", ptype);

  return ptype;
}

scheme_t eesox_scheme = {
  "EESOX",
  eesox_detect,
  eesox_readinfo,
  eesox_writeinfo,
  eesox_allocate,
  eesox_validate_change,
  eesox_validate_creation,
  eesox_validate_deletion,
  eesox_validate_partno,
  eesox_nexttype
};