fat.c

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/*
 * fat.c
 *
 * R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
 *
 * 2002-07-28 - [e-mail] - ported to ppcboot v1.1.6
 * 2003-03-10 - [e-mail] - ported to uboot
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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 <common.h>
#include <config.h>
#include <fat.h>
#include <asm/byteorder.h>
#include <part.h>

#if (CONFIG_COMMANDS & CFG_CMD_FAT)

//#define FAT_DPRINT printf

/*
 * Convert a string to lowercase.
 */
static void
downcase(char *str)
{
	while (*str != '\0') {
		TOLOWER(*str);
		str++;
	}
}

static  block_dev_desc_t *cur_dev = NULL;
static unsigned long part_offset = 0;
static int cur_part = 1;

#define DOS_PART_TBL_OFFSET	0x1be
#define DOS_PART_MAGIC_OFFSET	0x1fe
#define DOS_FS_TYPE_OFFSET	0x36

int disk_read (__u32 startblock, __u32 getsize, __u8 * bufptr)
{
	startblock += part_offset;
	if (cur_dev == NULL)
		return -1;
	if (cur_dev->block_read) {
		FAT_DPRINT("startblock: %d, getsize: %d,  offset: %d\n", startblock, getsize,part_offset);
		return cur_dev->block_read (cur_dev->dev, startblock, getsize, (unsigned long *)bufptr);
	}
	return -1;
}


int
fat_register_device(block_dev_desc_t *dev_desc, int part_no)
{
	unsigned char buffer[SECTOR_SIZE];

	if (!dev_desc->block_read)
		return -1;
	cur_dev=dev_desc;
	/* check if we have a MBR (on floppies we have only a PBR) */
	if (dev_desc->block_read (dev_desc->dev, 0, 1, (ulong *) buffer) != 1) {
		printf ("** Can't read from device %d **\n", dev_desc->dev);
		return -1;
	}
	if (buffer[DOS_PART_MAGIC_OFFSET] != 0x55 ||
		buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) {
		/* no signature found */
		return -1;
	}
	if(!strncmp(&buffer[DOS_FS_TYPE_OFFSET],"FAT",3)) {
		/* ok, we assume we are on a PBR only */
		cur_part = 1;
		part_offset=0;
	}
	else {
#if (CONFIG_COMMANDS & CFG_CMD_IDE) || (CONFIG_COMMANDS & CFG_CMD_SCSI) || \
    (CONFIG_COMMANDS & CFG_CMD_USB) || (CONFIG_COMMANDS & CFG_CMD_MMC)  ||defined(CONFIG_SYSTEMACE)
		disk_partition_t info;
		if(!get_partition_info(dev_desc, part_no, &info)) {
			part_offset = info.start;
			cur_part = part_no;
		}
		else {
			printf ("** Partition %d not valid on device %d **\n",part_no,dev_desc->dev);
			return -1;
		}
#else
		/* FIXME we need to determine the start block of the
		 * partition where the DOS FS resides. This can be done
		 * by using the get_partition_info routine. For this
		 * purpose the libpart must be included.
		 */
		part_offset=32;
		cur_part = 1;
#endif
	}
	return 0;
}


/*
 * Get the first occurence of a directory delimiter ('/' or '\') in a string.
 * Return index into string if found, -1 otherwise.
 */
static int
dirdelim(char *str)
{
	char *start = str;

	while (*str != '\0') {
		if (ISDIRDELIM(*str)) return str - start;
		str++;
	}
	return -1;
}


/*
 * Match volume_info fs_type strings.
 * Return 0 on match, -1 otherwise.
 */
static int
compare_sign(char *str1, char *str2)
{
	char *end = str1+SIGNLEN;

	while (str1 != end) {
		if (*str1 != *str2) {
			return -1;
		}
		str1++;
		str2++;
	}

	return 0;
}


/*
 * Extract zero terminated short name from a directory entry.
 */
static void get_name (dir_entry *dirent, char *s_name)
{
	char *ptr;

	memcpy (s_name, dirent->name, 8);
	s_name[8] = '\0';
	ptr = s_name;
	while (*ptr && *ptr != ' ')
		ptr++;
	if (dirent->ext[0] && dirent->ext[0] != ' ') {
		*ptr = '.';
		ptr++;
		memcpy (ptr, dirent->ext, 3);
		ptr[3] = '\0';
		while (*ptr && *ptr != ' ')
			ptr++;
	}
	*ptr = '\0';
	if (*s_name == DELETED_FLAG)
		*s_name = '\0';
	else if (*s_name == aRING)
		*s_name = '