fs/fdos/fs.c

/*
 * (C) Copyright 2002
 * Stäubli Faverges - <www.staubli.com>
 * Pierre AUBERT  p.aubert@staubli.com
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <config.h>
#include <malloc.h>

#include "dos.h"
#include "fdos.h"


/*-----------------------------------------------------------------------------
 * fill_fs -- Read info on file system
 *-----------------------------------------------------------------------------
 */
static int fill_fs (BootSector_t *boot, Fs_t *fs)
{

    fs -> fat_start = __le16_to_cpu (boot -> nrsvsect);
    fs -> fat_len = __le16_to_cpu (boot -> fatlen);
    fs -> nb_fat = boot -> nfat;

    fs -> dir_start = fs -> fat_start + fs -> nb_fat * fs -> fat_len;
    fs -> dir_len = __le16_to_cpu (boot -> dirents) * MDIR_SIZE / SZ_STD_SECTOR;
    fs -> cluster_size = boot -> clsiz;
    fs -> num_clus = (fs -> tot_sectors - fs -> dir_start - fs -> dir_len) / fs -> cluster_size;

    return (0);
}

/*-----------------------------------------------------------------------------
 * fs_init --
 *-----------------------------------------------------------------------------
 */
int fs_init (Fs_t *fs)
{
    BootSector_t *boot;

    /* Initialize physical device                                            */
    if (dev_open () < 0) {
	PRINTF ("Unable to initialize the fdc\n");
	return (-1);
    }
    init_subdir ();

    /* Allocate space for read the boot sector                               */
    if ((boot = (BootSector_t *)malloc (sizeof (BootSector_t))) == NULL) {
	PRINTF ("Unable to allocate space for boot sector\n");
	return (-1);
    }

    /* read boot sector                                                      */
    if (dev_read (boot, 0, 1)){
	PRINTF ("Error during boot sector read\n");
	free (boot);
	return (-1);
    }

    /* we verify it'a a DOS diskette                                         */
    if (boot -> jump [0] !=  JUMP_0_1 && boot -> jump [0] !=  JUMP_0_2) {
	PRINTF ("Not a DOS diskette\n");
	free (boot);
	return (-1);
    }

    if (boot -> descr < MEDIA_STD) {
	/* We handle only recent medias (type F0)                            */
	PRINTF ("unrecognized diskette type\n");
	free (boot);
	return (-1);
    }

    if (check_dev (boot, fs) < 0) {
	PRINTF ("Bad diskette\n");
	free (boot);
	return (-1);
    }

    if (fill_fs (boot, fs) < 0) {
	free (boot);

	return (-1);
    }

    /* Read FAT                                                              */
    if (read_fat (boot, fs) < 0) {
	free (boot);
	return (-1);
    }

    free (boot);
    return (0);
}