1038 lines
32 KiB
C
1038 lines
32 KiB
C
/****************************************************************************
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* apps/fsutils/mkfatfs/configfat.c
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*
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* Copyright (C) 2008-2009, 2013, 2017 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <inttypes.h>
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#include <stdint.h>
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#include <string.h>
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#include <debug.h>
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#include <errno.h>
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#include "fsutils/mkfatfs.h"
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#include "fat32.h"
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#include "mkfatfs.h"
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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#define NDX12 0
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#define NDX16 1
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#define NDX32 2
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#define fatconfig12 fatconfig[NDX12]
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#define fatconfig16 fatconfig[NDX16]
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#define fatconfig32 fatconfig[NDX32]
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/* JMP rel8 and NOP opcodes */
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#define OPCODE_JMP_REL8 0xeb
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#define OPCODE_NOP 0x90
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#define BOOTCODE_MSGOFFSET 29
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/****************************************************************************
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* Private Types
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****************************************************************************/
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struct fat_config_s
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{
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uint32_t fc_navailsects; /* The number of available sectors */
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uint32_t fc_nfatsects; /* The number of sectors in one FAT */
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uint32_t fc_nclusters; /* The number of clusters in the filesystem */
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uint32_t fc_rsvdseccount; /* The number of reserved sectors */
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};
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/****************************************************************************
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* Private Data
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****************************************************************************/
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/* Reverse engineered, generic boot message logic for non-bootable disk.
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* Message begins at offset 29; Sector relative offset must be poked into
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* offset 3.
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*/
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static uint8_t g_bootcodeblob[] =
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{
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0x0e, 0x1f, 0xbe, 0x00, 0x7c, 0xac, 0x22, 0xc0, 0x74, 0x0b, 0x56,
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0xb4, 0x0e, 0xbb, 0x07, 0x00, 0xcd, 0x10, 0x5e, 0xeb, 0xf0, 0x32,
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0xe4, 0xcd, 0x16, 0xcd, 0x19, 0xeb, 0xfe, 0x54, 0x68, 0x69, 0x73,
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0x20, 0x69, 0x73, 0x20, 0x6e, 0x6f, 0x74, 0x20, 0x61, 0x20, 0x62,
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0x6f, 0x6f, 0x74, 0x61, 0x62, 0x6c, 0x65, 0x20, 0x64, 0x69, 0x73,
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0x6b, 0x2e, 0x20, 0x20, 0x50, 0x6c, 0x65, 0x61, 0x73, 0x65, 0x20,
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0x69, 0x6e, 0x73, 0x65, 0x72, 0x74, 0x20, 0x61, 0x20, 0x62, 0x6f,
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0x6f, 0x74, 0x61, 0x62, 0x6c, 0x65, 0x20, 0x66, 0x6c, 0x6f, 0x70,
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0x70, 0x79, 0x20, 0x61, 0x6e, 0x64, 0x0d, 0x0a, 0x70, 0x72, 0x65,
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0x73, 0x73, 0x20, 0x61, 0x6e, 0x79, 0x20, 0x6b, 0x65, 0x79, 0x20,
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0x74, 0x6f, 0x20, 0x74, 0x72, 0x79, 0x20, 0x61, 0x67, 0x61, 0x69,
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0x6e, 0x20, 0x2e, 0x2e, 0x2e, 0x0d, 0x0a, 0x00
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};
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: mkfatfs_nfatsect12
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*
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* Description:
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* Calculate the number of sectors need for one fat in a FAT12 file system.
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*
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* Input:
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* fmt - Caller specified format parameters
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* var - Other format parameters that are not caller specifiable. (Most
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* set by mkfatfs_configfatfs()).
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* navailsects - The number of sectors available for both FAT and data.
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* This is a precalculated value equal to the total number of sectors
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* minus the number of root directory sectors and minus the number of
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* reserved sectors.
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*
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* Return:
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* 0: That calculation would have overflowed
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* >0: The size of one FAT in sectors.
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*
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****************************************************************************/
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static inline uint32_t
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mkfatfs_nfatsect12(FAR struct fat_format_s *fmt, FAR struct fat_var_s *var,
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uint32_t navailsects)
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{
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#ifdef CONFIG_HAVE_LONG_LONG
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uint64_t denom;
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uint64_t number;
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#else
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uint32_t denom;
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uint32_t number;
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#endif
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/* For FAT12, the cluster number is held in a 12-bit number or 1.5 bytes
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* per cluster reference. So each FAT sector will hold sectorsize/1.5
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* cluster references (except for the first sector of each FAT which has
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* two reserved 12-bit values). And the total number of FAT sectors needed
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* is:
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*
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* nfatsects = (1.5 * (ndataclust + 2) / sectorsize)
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*
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* where:
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*
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* ndataclust = ndatasect / clustsize
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* nvailsects = nfatsects + ndatasect
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*
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* The solution to this set of linear equations is:
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*
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* nfatsects = (3 * navailsects + 6 * clustersize) /
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* (3 * nfats + 2 * sectorsize * clustersize)
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*
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* The numerator would overflow uint32_t if:
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*
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* 3 * navailsects + 6 * clustersize > 0xffffffff
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*
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* Or
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*
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* navailsects > 0x55555555 - 2 * clustersize
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*/
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#ifndef CONFIG_HAVE_LONG_LONG
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if (navailsects <= (0x55555555 - (1 << (fmt->ff_clustshift + 1))))
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{
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#endif
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denom = (fmt->ff_nfats << 1) + fmt->ff_nfats
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+ (var->fv_sectorsize << (fmt->ff_clustshift + 1));
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number = (navailsects << 1) + navailsects
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+ (1 << (fmt->ff_clustshift + 2))
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+ (1 << (fmt->ff_clustshift + 1));
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return (uint32_t)((number + denom - 1) / denom);
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#ifndef CONFIG_HAVE_LONG_LONG
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}
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else
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{
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return 0;
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}
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#endif
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}
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/****************************************************************************
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* Name: mkfatfs_nfatsect16
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*
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* Description:
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* Calculate the number of sectors need for one fat in a FAT16 file system.
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*
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* Input:
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* fmt - Caller specified format parameters
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* var - Other format parameters that are not caller specifiable. (Most
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* set by mkfatfs_configfatfs()).
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* navailsects - The number of sectors available for both FAT and data.
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* This is a precalculated value equal to the total number of sectors
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* minus the number of root directory sectors and minus the number of
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* reserved sectors.
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*
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* Return:
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* The size of one FAT in sectors.
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*
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****************************************************************************/
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static inline uint32_t
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mkfatfs_nfatsect16(FAR struct fat_format_s *fmt, FAR struct fat_var_s *var,
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uint32_t navailsects)
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{
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#ifdef CONFIG_HAVE_LONG_LONG
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uint64_t denom;
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uint64_t number;
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#else
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uint32_t denom;
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uint32_t number;
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#endif
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/* For FAT16, the cluster number is held in a 16-bit number or 2 bytes per
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* cluster reference. So each FAT sector will hold sectorsize/2 cluster
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* references (except for the first sector of each FAT which has two
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* reserved 16-bit values). And the total number of FAT sectors needed is:
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*
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* nfatsects = (2 * (ndataclust + 2) / sectorsize)
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*
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* where:
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*
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* ndataclust = ndatasect / clustsize
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* nvailsects = nfatsects + ndatasect
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*
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* The solution to this set of linear equations is:
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*
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* nfatsects = (navailsects + 2 * clustersize) /
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* (nfats + sectorsize * clustersize / 2)
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*
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* Overflow in the calculation of the numerator could occur if:
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*
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* navailsects > 0xffffffff - 2 * clustersize
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*/
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if (fmt->ff_clustshift == 0)
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{
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denom = fmt->ff_nfats + (var->fv_sectorsize >> 1);
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number = navailsects + 2;
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}
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else
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{
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denom = fmt->ff_nfats +
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(var->fv_sectorsize << (fmt->ff_clustshift - 1));
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number = navailsects + (1 << (fmt->ff_clustshift + 1));
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}
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return (uint32_t)((number + denom - 1) / denom);
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}
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/****************************************************************************
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* Name: mkfatfs_nfatsect32
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*
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* Description:
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* Calculate the number of sectors need for one fat in a FAT32 file system.
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*
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* Input:
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* fmt - Caller specified format parameters
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* var - Other format parameters that are not caller specifiable. (Most
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* set by mkfatfs_configfatfs()).
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* navailsects - The number of sectors available for both FAT and data.
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* This is a precalculated value equal to the total number of sectors
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* minus the number of root directory sectors and minus the number of
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* reserved sectors.
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*
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* Return:
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* The size of one FAT in sectors.
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*
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****************************************************************************/
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static inline uint32_t
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mkfatfs_nfatsect32(FAR struct fat_format_s *fmt, FAR struct fat_var_s *var,
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uint32_t navailsects)
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{
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#ifdef CONFIG_HAVE_LONG_LONG
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uint64_t denom;
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uint64_t number;
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#else
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uint32_t denom;
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uint32_t number;
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#endif
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/* For FAT32, the cluster number is held in a 32-bit number or 4 bytes per
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* cluster reference. So each FAT sector will hold sectorsize/4 cluster
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* references (except for the first sector of each FAT which has three
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* reserved 32-bit values). And the total number of FAT sectors needed is:
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*
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* nfatsects = (4 * (ndataclust + 3) / sectorsize)
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*
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* where:
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*
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* ndataclust = ndatasect / clustsize
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* nvailsects = nfatsects + ndatasect
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*
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* The solution to this set of linear equations is:
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*
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* nfatsects = (navailsects + 3 * clustersize) /
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* (nfats + sectorsize * clustersize / 4)
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*
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* Overflow in the 32-bit calculation of the numerator could occur if:
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*
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* navailsects > 0xffffffff - 3 * clustersize
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*/
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if (fmt->ff_clustshift == 0)
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{
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denom = fmt->ff_nfats + (var->fv_sectorsize >> 2);
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number = navailsects + 3;
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}
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else if (fmt->ff_clustshift == 1)
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{
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denom = fmt->ff_nfats + (var->fv_sectorsize >> 1);
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number = navailsects + 6;
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}
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else
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{
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denom = fmt->ff_nfats +
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(var->fv_sectorsize << (fmt->ff_clustshift - 2));
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number = navailsects + (1 << (fmt->ff_clustshift + 1)) +
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(1 << fmt->ff_clustshift);
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}
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return (uint32_t)((number + denom - 1) / denom);
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}
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/****************************************************************************
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* Name: mkfatfs_clustersearchlimits
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*
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* Description:
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* Pick the starting and ending cluster size to use in the search for the
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* the optimal cluster size.
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*
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* Input:
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* fmt - Caller specified format parameters
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* var - Other format parameters that are not caller specifiable. (Most
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* set by mkfatfs_configfatfs()).
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*
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* Return:
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* Starting cluster size is set in fmt->ff_clustshift; Final cluster
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* size is the returned value.
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*
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****************************************************************************/
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static inline uint8_t
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mkfatfs_clustersearchlimits(FAR struct fat_format_s *fmt,
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FAR struct fat_var_s *var)
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{
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uint8_t mxclustshift;
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/* Did the caller already pick the cluster size? If not, the clustshift
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* value will be 0xff
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*/
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if (fmt->ff_clustshift == 0xff)
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{
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/* Pick a starting size based on the number of sectors on the device */
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if (fmt->ff_nsectors < 2048)
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{
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/* 2k sectors, start with 1 sector/cluster. */
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fmt->ff_clustshift = 0;
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}
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else if (fmt->ff_nsectors < 4096)
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{
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/* 4k sectors, start with 2 sector/cluster. */
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fmt->ff_clustshift = 1;
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}
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else if (fmt->ff_nsectors < 8192)
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{
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/* 8k sectors, start with 4 sector/cluster. */
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fmt->ff_clustshift = 2;
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}
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else if (fmt->ff_nsectors < 16384)
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{
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/* 16k sectors, start with 8 sector/cluster. */
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fmt->ff_clustshift = 3;
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}
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else if (fmt->ff_nsectors < 32768)
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{
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/* 32k sectors, start with 16 sector/cluster. */
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fmt->ff_clustshift = 4;
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}
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else
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{
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/* Otherwise, 32 sector/cluster. */
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fmt->ff_clustshift = 5;
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}
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/* Wherever the search starts, it will end with the maximum of
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* 128 sectors per cluster
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*/
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mxclustshift = 7;
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}
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else
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{
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/* The caller has selected a cluster size. There will be no search!
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* Just set the maximum to the caller specified value.
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*/
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mxclustshift = fmt->ff_clustshift;
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}
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return mxclustshift;
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}
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/****************************************************************************
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* Name: mkfatfs_tryfat12
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*
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* Description:
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* Try to define a FAT12 filesystem on the device using the candidate
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* sectors per cluster
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*
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* Input:
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* fmt - Caller specified format parameters
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* var - Other format parameters that are not caller specifiable. (Most
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* set by mkfatfs_configfatfs()).
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* config - FAT12-specific configuration
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*
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* Return:
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* Zero on success configuration of a FAT12 file system; negated errno
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* on failure
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*
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****************************************************************************/
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static inline int
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mkfatfs_tryfat12(FAR struct fat_format_s *fmt, FAR struct fat_var_s *var,
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FAR struct fat_config_s *config)
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{
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uint32_t maxnclusters;
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/* Calculate the number sectors in one FAT required to access all of the
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* available sectors.
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*/
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config->fc_nfatsects = mkfatfs_nfatsect12(fmt, var,
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config->fc_navailsects);
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if (config->fc_nfatsects > 0)
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{
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/* Calculate the number of clusters available given the number of
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* available sectors and the number of those that will be used for FAT:
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*/
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config->fc_nclusters =
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(config->fc_navailsects -
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fmt->ff_nfats * config->fc_nfatsects) >> fmt->ff_clustshift;
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/* Calculate the maximum number of clusters that could be supported by
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* a FAT of this size.
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*
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* maxnclusters = nfatsects * sectorsize / 1.5 - 2
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*/
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maxnclusters = (config->fc_nfatsects << (var->fv_sectshift + 1)) / 3;
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if (maxnclusters > FAT_MAXCLUST12)
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{
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maxnclusters = FAT_MAXCLUST12;
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}
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finfo("nfatsects=%" PRIu32 " nclusters=%" PRIu32
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" (max=%" PRIu32 ")\n",
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config->fc_nfatsects, config->fc_nclusters, maxnclusters);
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/* Check if this number of clusters would overflow the maximum for
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* FAT12 (remembering that two FAT cluster slots are reserved).
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*/
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if (config->fc_nclusters + 2 > maxnclusters)
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{
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fwarn("WARNING: Too many clusters for FAT12: %"
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PRId32 " > %" PRId32 "\n",
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config->fc_nclusters, maxnclusters - 2);
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return -ENFILE;
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}
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}
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return 0;
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}
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/****************************************************************************
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* Name: mkfatfs_tryfat16
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*
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* Description:
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* Try to define a FAT16 filesystem on the device using the candidate
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* sectors per cluster
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*
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* Input:
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* fmt - Caller specified format parameters
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* var - Other format parameters that are not caller specifiable. (Most
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* set by mkfatfs_configfatfs()).
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* config - FAT16-specific configuration
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*
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* Return:
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* Zero on success configuration of a FAT16 file system; negated errno
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* on failure
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*
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****************************************************************************/
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static inline int
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mkfatfs_tryfat16(FAR struct fat_format_s *fmt, FAR struct fat_var_s *var,
|
|
FAR struct fat_config_s *config)
|
|
{
|
|
uint32_t maxnclusters;
|
|
|
|
/* Calculate the number sectors in one FAT required to access all of the
|
|
* available sectors.
|
|
*/
|
|
|
|
config->fc_nfatsects = mkfatfs_nfatsect16(fmt, var,
|
|
config->fc_navailsects);
|
|
if (config->fc_nfatsects > 0)
|
|
{
|
|
/* Calculate the number of clusters available given the number of
|
|
* available sectors and the number of those that will be used for FAT:
|
|
*/
|
|
|
|
config->fc_nclusters =
|
|
(config->fc_navailsects -
|
|
fmt->ff_nfats * config->fc_nfatsects) >> fmt->ff_clustshift;
|
|
|
|
/* Calculate the maximum number of clusters that could be supported by
|
|
* a FAT of this size.
|
|
*
|
|
* maxnclusters = nfatsects * sectorsize / 2 - 2
|
|
*/
|
|
|
|
maxnclusters = config->fc_nfatsects << (var->fv_sectshift - 1);
|
|
if (maxnclusters > FAT_MAXCLUST16)
|
|
{
|
|
maxnclusters = FAT_MAXCLUST16;
|
|
}
|
|
|
|
finfo("nfatsects=%" PRIu32 " nclusters=%" PRIu32
|
|
" (min=%u max=%" PRIu32 ")\n",
|
|
config->fc_nfatsects, config->fc_nclusters, FAT_MINCLUST16,
|
|
maxnclusters);
|
|
|
|
/* Check if this number of clusters would overflow the maximum for
|
|
* FAT16 (remembering that two FAT cluster slots are reserved).
|
|
* Check the lower limit as well. The FAT12 is distinguished from
|
|
* FAT16 by comparing the number of clusters on the device against a
|
|
* known threshold. If a small FAT16 file system were created, then
|
|
* it would be confused as a FAT12 at mount time.
|
|
*/
|
|
|
|
if ((config->fc_nclusters + 2 > maxnclusters) ||
|
|
(config->fc_nclusters < FAT_MINCLUST16))
|
|
{
|
|
fwarn("WARNING: Too few or too many clusters for FAT16: "
|
|
"%d < %" PRId32 " < %" PRId32 "\n",
|
|
FAT_MINCLUST16, config->fc_nclusters, maxnclusters - 2);
|
|
|
|
return -ENFILE;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: mkfatfs_tryfat32
|
|
*
|
|
* Description:
|
|
* Try to define a FAT32 filesystem on the device using the candidate
|
|
* sectors per cluster
|
|
*
|
|
* Input:
|
|
* fmt - Caller specified format parameters
|
|
* var - Other format parameters that are not caller specifiable. (Most
|
|
* set by mkfatfs_configfatfs()).
|
|
* config - FAT32-specific configuration
|
|
*
|
|
* Return:
|
|
* Zero on success configuration of a FAT32 file system; negated errno
|
|
* on failure
|
|
*
|
|
****************************************************************************/
|
|
|
|
static inline int
|
|
mkfatfs_tryfat32(FAR struct fat_format_s *fmt, FAR struct fat_var_s *var,
|
|
FAR struct fat_config_s *config)
|
|
{
|
|
uint32_t maxnclusters;
|
|
|
|
/* Calculate the number sectors in one FAT required to access all of the
|
|
* available sectors.
|
|
*/
|
|
|
|
config->fc_nfatsects = mkfatfs_nfatsect32(fmt, var,
|
|
config->fc_navailsects);
|
|
if (config->fc_nfatsects > 0)
|
|
{
|
|
/* Calculate the number of clusters available given the number of
|
|
* available sectors and the number of those that will be used for FAT:
|
|
*/
|
|
|
|
config->fc_nclusters =
|
|
(config->fc_navailsects -
|
|
fmt->ff_nfats * config->fc_nfatsects) >> fmt->ff_clustshift;
|
|
|
|
/* Calculate the maximum number of clusters that could be supported by
|
|
* a FAT of this size.
|
|
*
|
|
* maxnclusters = nfatsects * sectorsize / 4 - 2
|
|
*/
|
|
|
|
maxnclusters = (config->fc_nfatsects << (var->fv_sectshift - 2));
|
|
if (maxnclusters > FAT_MAXCLUST32)
|
|
{
|
|
maxnclusters = FAT_MAXCLUST32;
|
|
}
|
|
|
|
finfo("nfatsects=%" PRIu32 " nclusters=%" PRIu32
|
|
" (max=%" PRIu32 ")\n",
|
|
config->fc_nfatsects, config->fc_nclusters, maxnclusters);
|
|
|
|
/* Check if this number of clusters would overflow the maximum for
|
|
* FAT32 (remembering that two FAT cluster slots are reserved).
|
|
*/
|
|
|
|
if ((config->fc_nclusters + 3 > maxnclusters) ||
|
|
(config->fc_nclusters < FAT_MINCLUST32))
|
|
{
|
|
fwarn("WARNING: Too few or too many clusters for FAT32: "
|
|
"%d < %" PRId32 " < %" PRId32 "\n",
|
|
FAT_MINCLUST32, config->fc_nclusters, maxnclusters - 3);
|
|
|
|
return -ENFILE;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: mkfatfs_selectfat
|
|
*
|
|
* Description:
|
|
* The cluster search has succeeded, select the specified FAT FS
|
|
*
|
|
* Input:
|
|
* fattype - The FAT size selected
|
|
* fmt - Caller specified format parameters
|
|
* var - Format parameters that are not caller specifiable.
|
|
*
|
|
* Return:
|
|
* None
|
|
*
|
|
****************************************************************************/
|
|
|
|
static inline void
|
|
mkfatfs_selectfat(int fattype, FAR struct fat_format_s *fmt,
|
|
FAR struct fat_var_s *var, FAR struct fat_config_s *config)
|
|
{
|
|
/* Return the appropriate information about the selected file system. */
|
|
|
|
finfo("Selected FAT%d\n", fattype);
|
|
|
|
var->fv_fattype = fattype;
|
|
var->fv_nclusters = config->fc_nclusters;
|
|
var->fv_nfatsects = config->fc_nfatsects;
|
|
fmt->ff_rsvdseccount = config->fc_rsvdseccount;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: mkfatfs_clustersearch
|
|
*
|
|
* Description:
|
|
* Search to find the smallest (reasonable) cluster size for the FAT file
|
|
* system.
|
|
*
|
|
* Input:
|
|
* fmt - Caller specified format parameters
|
|
* var - Other format parameters that are not caller specifiable. (Most
|
|
* set by mkfatfs_configfatfs()).
|
|
*
|
|
* Return:
|
|
* Zero on success; negated errno on failure
|
|
*
|
|
****************************************************************************/
|
|
|
|
static inline int
|
|
mkfatfs_clustersearch(FAR struct fat_format_s *fmt,
|
|
FAR struct fat_var_s *var)
|
|
{
|
|
struct fat_config_s fatconfig[3];
|
|
uint8_t mxclustshift;
|
|
|
|
memset(fatconfig, 0, 3*sizeof(struct fat_config_s));
|
|
|
|
/* Select the reserved sector count for each FAT size */
|
|
|
|
if (fmt->ff_rsvdseccount)
|
|
{
|
|
fatconfig12.fc_rsvdseccount = fmt->ff_rsvdseccount;
|
|
fatconfig16.fc_rsvdseccount = fmt->ff_rsvdseccount;
|
|
|
|
if (fmt->ff_rsvdseccount < 2)
|
|
{
|
|
fwarn("WARNING: At least 2 reserved sectors needed by FAT32\n");
|
|
fatconfig32.fc_rsvdseccount = 2;
|
|
}
|
|
else
|
|
{
|
|
fatconfig32.fc_rsvdseccount = fmt->ff_rsvdseccount;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
fatconfig12.fc_rsvdseccount = 1;
|
|
fatconfig16.fc_rsvdseccount = 1;
|
|
fatconfig32.fc_rsvdseccount = 32;
|
|
}
|
|
|
|
/* Determine the number of sectors needed by the root directory.
|
|
* This is a constant value, independent of cluster size for FAT12/16
|
|
*/
|
|
|
|
if (var->fv_fattype != 32)
|
|
{
|
|
/* Calculate the number of sectors reqired to contain the selected
|
|
* number of root directory entries. This value is save in the var
|
|
* structure but will be overwritten if FAT32 is selected. FAT32 uses
|
|
* a cluster chain for the root directory, so the concept of the number
|
|
* of root directory entries does not apply to FAT32
|
|
*/
|
|
|
|
var->fv_nrootdirsects =
|
|
((fmt->ff_rootdirentries << DIR_SHIFT) +
|
|
var->fv_sectorsize - 1) >> var->fv_sectshift;
|
|
|
|
/* The number of data sectors available (includes the fat itself)
|
|
* This value is a constant for FAT12/16, but not FAT32 because the
|
|
* size of the root directory cluster changes
|
|
*/
|
|
|
|
fatconfig12.fc_navailsects =
|
|
fatconfig16.fc_navailsects =
|
|
fmt->ff_nsectors - var->fv_nrootdirsects -
|
|
fatconfig12.fc_rsvdseccount;
|
|
}
|
|
|
|
/* Select an initial and terminal cluster size to use in the search
|
|
* (if these values were not provided by the caller)
|
|
*/
|
|
|
|
mxclustshift = mkfatfs_clustersearchlimits(fmt, var);
|
|
|
|
do
|
|
{
|
|
finfo("Configuring with %d sectors/cluster...\n",
|
|
1 << fmt->ff_clustshift);
|
|
|
|
/* Check if FAT12 has not been excluded */
|
|
|
|
if (var->fv_fattype == 0 || var->fv_fattype == 12)
|
|
{
|
|
/* Try to configure a FAT12 file system with this cluster size */
|
|
|
|
if (mkfatfs_tryfat12(fmt, var, &fatconfig12) != 0)
|
|
{
|
|
fwarn("WARNING: Cannot format FAT12 at %u sectors/cluster\n",
|
|
1 << fmt->ff_clustshift);
|
|
|
|
fatconfig12.fc_nfatsects = 0;
|
|
fatconfig12.fc_nclusters = 0;
|
|
}
|
|
}
|
|
|
|
/* Check if FAT16 has not been excluded */
|
|
|
|
if (var->fv_fattype == 0 || var->fv_fattype == 16)
|
|
{
|
|
/* Try to configure a FAT16 file system with this cluster size */
|
|
|
|
if (mkfatfs_tryfat16(fmt, var, &fatconfig16) != 0)
|
|
{
|
|
fwarn("WARNING: Cannot format FAT16 at %u sectors/cluster\n",
|
|
1 << fmt->ff_clustshift);
|
|
|
|
fatconfig16.fc_nfatsects = 0;
|
|
fatconfig16.fc_nclusters = 0;
|
|
}
|
|
}
|
|
|
|
/* If either FAT12 or 16 was configured at this sector/cluster setting,
|
|
* then finish the configuration and break out now
|
|
*/
|
|
|
|
if (fatconfig12.fc_nclusters || fatconfig16.fc_nclusters)
|
|
{
|
|
if ((!var->fv_fattype &&
|
|
fatconfig16.fc_nclusters > fatconfig12.fc_nclusters) ||
|
|
(var ->fv_fattype == 16))
|
|
{
|
|
/* The caller has selected FAT16 -OR- no FAT type has been
|
|
* selected, but the FAT16 selection has more clusters.
|
|
* Select FAT16.
|
|
*/
|
|
|
|
mkfatfs_selectfat(16, fmt, var, &fatconfig16);
|
|
}
|
|
else
|
|
{
|
|
/* The caller has selected FAT12 -OR- no FAT type has been
|
|
* selected, but the FAT12 selected has more clusters.
|
|
* Selected FAT12
|
|
*/
|
|
|
|
mkfatfs_selectfat(12, fmt, var, &fatconfig12);
|
|
}
|
|
|
|
return OK;
|
|
}
|
|
|
|
#if 0
|
|
/* Check if FAT32 has not been excluded */
|
|
|
|
if (var->fv_fattype == 0 || var->fv_fattype == 32)
|
|
#else
|
|
/* FAT32 must be explicitly requested */
|
|
|
|
if (var->fv_fattype == 32)
|
|
#endif
|
|
{
|
|
/* The number of data sectors available (includes the fat itself)
|
|
* This value is a constant with respect to cluster size for
|
|
* FAT12/16, but not FAT32 because the size of the root directory
|
|
* cluster changes with cluster size.
|
|
*/
|
|
|
|
fatconfig32.fc_navailsects = fmt->ff_nsectors -
|
|
(1 << fmt->ff_clustshift) -
|
|
fatconfig32.fc_rsvdseccount;
|
|
|
|
/* Try to configure a FAT32 file system with this cluster size */
|
|
|
|
if (mkfatfs_tryfat32(fmt, var, &fatconfig32) != 0)
|
|
{
|
|
fwarn("WARNING: Cannot format FAT32 at %u sectors/cluster\n",
|
|
1 << fmt->ff_clustshift);
|
|
|
|
fatconfig32.fc_nfatsects = 0;
|
|
fatconfig32.fc_nclusters = 0;
|
|
}
|
|
else
|
|
{
|
|
/* Select FAT32 if we have not already done so */
|
|
|
|
mkfatfs_selectfat(32, fmt, var, &fatconfig32);
|
|
return OK;
|
|
}
|
|
}
|
|
|
|
/* Otherwise, bump up the sectors/cluster for the next time around
|
|
* the loop.
|
|
*/
|
|
|
|
fmt->ff_clustshift++;
|
|
}
|
|
while (fmt->ff_clustshift <= mxclustshift);
|
|
|
|
return -ENFILE;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: mkfatfs_configfatfs
|
|
*
|
|
* Description:
|
|
* Based on the geometry of the block device and upon the caller-selected
|
|
* values, configure the FAT filesystem for the device.
|
|
*
|
|
* Input:
|
|
* fmt - Caller specified format parameters
|
|
* var - Holds disk geometry data. Also, the location to return FAT
|
|
* configuration data
|
|
*
|
|
* Return:
|
|
* Zero on success; negated errno on failure
|
|
*
|
|
****************************************************************************/
|
|
|
|
int mkfatfs_configfatfs(FAR struct fat_format_s *fmt,
|
|
FAR struct fat_var_s *var)
|
|
{
|
|
int ret;
|
|
|
|
/* Select the number of root directory entries (FAT12/16 only).
|
|
* If FAT32 is selected, this value will be cleared later
|
|
*/
|
|
|
|
if (!fmt->ff_rootdirentries)
|
|
{
|
|
/* The caller did not specify the number of root directory entries;
|
|
* use a default of 512.
|
|
*/
|
|
|
|
fmt->ff_rootdirentries = 512;
|
|
}
|
|
|
|
/* Search to determine the smallest (reasonable) cluster size.
|
|
* A by-product of this search will be the selection of the FAT size
|
|
* (12/16/32) if the caller has not specified the FAT size
|
|
*/
|
|
|
|
ret = mkfatfs_clustersearch(fmt, var);
|
|
if (ret < 0)
|
|
{
|
|
ferr("WARNING: Failed to set cluster size\n");
|
|
return ret;
|
|
}
|
|
|
|
/* Perform FAT specific initialization */
|
|
|
|
/* Set up boot jump assuming FAT 12/16 offset to bootcode */
|
|
|
|
var->fv_jump[0] = OPCODE_JMP_REL8;
|
|
var->fv_jump[2] = OPCODE_NOP;
|
|
var->fv_bootcode = g_bootcodeblob;
|
|
var->fv_bootcodesize = sizeof(g_bootcodeblob);
|
|
|
|
if (var->fv_fattype != 32)
|
|
{
|
|
/* Set up additional, non-zero FAT12/16 fields */
|
|
|
|
/* Patch in the correct offset to the boot code */
|
|
|
|
var->fv_jump[1] = MBR16_BOOTCODE - 2;
|
|
g_bootcodeblob[3] = MBR16_BOOTCODE + BOOTCODE_MSGOFFSET;
|
|
}
|
|
else
|
|
{
|
|
/* Patch in the correct offset to the boot code */
|
|
|
|
var->fv_jump[1] = MBR32_BOOTCODE - 2;
|
|
g_bootcodeblob[3] = MBR32_BOOTCODE + BOOTCODE_MSGOFFSET;
|
|
|
|
/* The root directory is a cluster chain... its is initialize size is
|
|
* one cluster
|
|
*/
|
|
|
|
var->fv_nrootdirsects = 1 << fmt->ff_clustshift;
|
|
|
|
/* The number of reported root directory entries should should be zero
|
|
* for FAT32 because the root directory is a cluster chain.
|
|
*/
|
|
|
|
fmt->ff_rootdirentries = 0;
|
|
|
|
/* Verify the caller's backupboot selection */
|
|
|
|
if (fmt->ff_backupboot <= 1 ||
|
|
fmt->ff_backupboot >= fmt->ff_rsvdseccount)
|
|
{
|
|
ferr("WARNING: Invalid backup boot sector: %d\n",
|
|
fmt->ff_backupboot);
|
|
fmt->ff_backupboot = 0;
|
|
}
|
|
|
|
/* Check if the caller has selected a location for the backup boot
|
|
* record
|
|
*/
|
|
|
|
if (!fmt->ff_backupboot)
|
|
{
|
|
/* There must be reserved sectors in order to have a backup boot
|
|
* sector
|
|
*/
|
|
|
|
if (fmt->ff_rsvdseccount >= 2)
|
|
{
|
|
/* Sector 0 is the MBR; 1... ff_rsvdseccount are reserved.
|
|
* Try the next the last reserved sector.
|
|
*/
|
|
|
|
fmt->ff_backupboot = fmt->ff_rsvdseccount - 1;
|
|
if (fmt->ff_backupboot > 6)
|
|
{
|
|
/* Limit the location to within the first 7 */
|
|
|
|
fmt->ff_backupboot = 6;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Report the selected fat type */
|
|
|
|
fmt->ff_fattype = var->fv_fattype;
|
|
|
|
/* Describe the configured filesystem */
|
|
|
|
#ifdef CONFIG_DEBUG_FEATURES
|
|
finfo("Sector size: %" PRId32 " bytes\n", var->fv_sectorsize);
|
|
finfo("Number of sectors: %" PRId32 " sectors\n", fmt->ff_nsectors);
|
|
finfo("FAT size: %d bits\n", var->fv_fattype);
|
|
finfo("Number FATs: %d\n", fmt->ff_nfats);
|
|
finfo("Sectors per cluster: %d sectors\n", 1 << fmt->ff_clustshift);
|
|
finfo("FS size: %" PRId32 " sectors\n", var->fv_nfatsects);
|
|
finfo(" %" PRId32 " clusters\n", var->fv_nclusters);
|
|
|
|
if (var->fv_fattype != 32)
|
|
{
|
|
finfo("Root directory slots: %d\n", fmt->ff_rootdirentries);
|
|
}
|
|
|
|
finfo("Volume ID: %08" PRIx32 "\n", fmt->ff_volumeid);
|
|
finfo("Volume Label: \"%c%c%c%c%c%c%c%c%c%c%c\"\n",
|
|
fmt->ff_volumelabel[0], fmt->ff_volumelabel[1], fmt->ff_volumelabel[2],
|
|
fmt->ff_volumelabel[3], fmt->ff_volumelabel[4], fmt->ff_volumelabel[5],
|
|
fmt->ff_volumelabel[6], fmt->ff_volumelabel[7], fmt->ff_volumelabel[8],
|
|
fmt->ff_volumelabel[9], fmt->ff_volumelabel[10]);
|
|
#endif
|
|
return OK;
|
|
}
|