fat.c

AT91RM9200的完整启动代码：包括loader, boot及U-boot三部分均已编译通过！欢迎下载使用！

/*
 * 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>

#if (CONFIG_COMMANDS & CFG_CMD_FAT)

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

int (*dev_block_read)(int device, __u32 blknr, __u32 blkcnt, __u8 *buffer) = 0;

int disk_read (__u32 startblock, __u32 getsize, __u8 * bufptr)
{
	/* FIXME we need to determine the start block of the
	 * partition where the DOS FS resides
	 */
	startblock += 32;

	if (dev_block_read) {
		return dev_block_read (0, startblock, getsize, bufptr);
	}
	return -1;
}


int
fat_register_read (int (*block_read)(int, __u32, __u32, __u8 *))
{
	dev_block_read = block_read;
	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 = '