source: mainline/uspace/app/mkfat/mkfat.c@ 1e58e1b

/*
 * Copyright (c) 2010 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup fs
 * @{
 */

/**
 * @file        mkfat.c
 * @brief       Tool for creating new FAT file systems.
 *
 * Currently we can create 12/16/32-bit FAT.
 */

#include <stdio.h>
#include <stdlib.h>
#include <block.h>
#include <mem.h>
#include <loc.h>
#include <byteorder.h>
#include <sys/types.h>
#include <sys/typefmt.h>
#include <inttypes.h>
#include <errno.h>
#include "fat.h"

#define NAME    "mkfat"

/** Divide and round up. */
#define div_round_up(a, b) (((a) + (b) - 1) / (b))

/** Default file-system parameters */
enum {
        default_sector_size             = 512,
        default_sectors_per_cluster     = 4,
        default_fat_count               = 2,
        default_reserved_clusters       = 2,
        default_media_descriptor        = 0xF8 /**< fixed disk */
};

/** Configurable file-system parameters */
typedef struct fat_cfg {
        int fat_type; /* FAT12 = 12, FAT16 = 16, FAT32 = 32 */
        size_t sector_size;
        uint32_t total_sectors;
        uint16_t root_ent_max;
        uint32_t addt_res_sectors;
        uint8_t sectors_per_cluster;

        uint16_t reserved_sectors;
        uint32_t rootdir_sectors;
        uint32_t fat_sectors;
        uint32_t total_clusters;
        uint8_t fat_count;
} fat_cfg_t;

static void syntax_print(void);

static int fat_params_compute(struct fat_cfg *cfg);
static int fat_blocks_write(struct fat_cfg const *cfg, service_id_t service_id);
static void fat_bootsec_create(struct fat_cfg const *cfg, struct fat_bs *bs);

int main(int argc, char **argv)
{
        struct fat_cfg cfg;

        int rc;
        char *dev_path;
        service_id_t service_id;
        char *endptr;
        aoff64_t dev_nblocks;

        cfg.sector_size = default_sector_size;
        cfg.sectors_per_cluster = default_sectors_per_cluster;
        cfg.fat_count = default_fat_count;
        cfg.total_sectors = 0;
        cfg.addt_res_sectors = 0;
        cfg.root_ent_max = 128;
        cfg.fat_type = FAT16;

        if (argc < 2) {
                printf(NAME ": Error, argument missing.\n");
                syntax_print();
                return 1;
        }

        --argc; ++argv;
        if (str_cmp(*argv, "--size") == 0) {
                --argc; ++argv;
                if (*argv == NULL) {
                        printf(NAME ": Error, argument missing.\n");
                        syntax_print();
                        return 1;
                }

                cfg.total_sectors = strtol(*argv, &endptr, 10);
                if (*endptr != '\0') {
                        printf(NAME ": Error, invalid argument.\n");
                        syntax_print();
                        return 1;
                }

                --argc; ++argv;
        }

        if (str_cmp(*argv, "--type") == 0) {
                --argc; ++argv;
                if (*argv == NULL) {
                        printf(NAME ": Error, argument missing.\n");
                        syntax_print();
                        return 1;
                }

                cfg.fat_type = strtol(*argv, &endptr, 10);
                if (*endptr != '\0') {
                        printf(NAME ": Error, invalid argument.\n");
                        syntax_print();
                        return 1;
                }

                --argc; ++argv;
        }

        if (argc != 1) {
                printf(NAME ": Error, unexpected argument.\n");
                syntax_print();
                return 1;
        }

        dev_path = *argv;
        printf("Device: %s\n", dev_path);

        rc = loc_service_get_id(dev_path, &service_id, 0);
        if (rc != EOK) {
                printf(NAME ": Error resolving device `%s'.\n", dev_path);
                return 2;
        }

        rc = block_init(EXCHANGE_SERIALIZE, service_id, 2048);
        if (rc != EOK)  {
                printf(NAME ": Error initializing libblock.\n");
                return 2;
        }

        rc = block_get_bsize(service_id, &cfg.sector_size);
        if (rc != EOK) {
                printf(NAME ": Error determining device block size.\n");
                return 2;
        }

        rc = block_get_nblocks(service_id, &dev_nblocks);
        if (rc != EOK) {
                printf(NAME ": Warning, failed to obtain block device size.\n");
        } else {
                printf(NAME ": Block device has %" PRIuOFF64 " blocks.\n",
                    dev_nblocks);
                if (!cfg.total_sectors || dev_nblocks < cfg.total_sectors)
                        cfg.total_sectors = dev_nblocks;
        }

        if (cfg.total_sectors == 0) {
                printf(NAME ": Error. You must specify filesystem size.\n");
                return 1;
        }

        if (cfg.fat_type != FAT12 && cfg.fat_type != FAT16 && cfg.fat_type != FAT32) {
                printf(NAME ": Error. Unknown FAT type.\n");
                return 2;
        }

        printf(NAME ": Creating FAT%d filesystem on device %s.\n", cfg.fat_type, dev_path);

        rc = fat_params_compute(&cfg);
        if (rc != EOK) {
                printf(NAME ": Invalid file-system parameters.\n");
                return 2;
        }

        rc = fat_blocks_write(&cfg, service_id);
        if (rc != EOK) {
                printf(NAME ": Error writing device.\n");
                return 2;
        }

        block_fini(service_id);
        printf("Success.\n");

        return 0;
}

static void syntax_print(void)
{
        printf("syntax: mkfat [--size <sectors>] [--type 12|16|32] <device_name>\n");
}

/** Derive sizes of different filesystem structures.
 *
 * This function concentrates all the different computations of FAT
 * file system params.
 */
static int fat_params_compute(struct fat_cfg *cfg)
{
        uint32_t fat_bytes;
        uint32_t non_data_sectors_lb;

        /*
         * Make a conservative guess on the FAT size needed for the file
         * system. The optimum could be potentially smaller since we
         * do not subtract size of the FAT itself when computing the
         * size of the data region.
         */

        cfg->reserved_sectors = 1 + cfg->addt_res_sectors;
        if (cfg->fat_type != FAT32) {
                cfg->rootdir_sectors = div_round_up(cfg->root_ent_max * DIRENT_SIZE,
                        cfg->sector_size);
        } else
                cfg->rootdir_sectors = 0;
        non_data_sectors_lb = cfg->reserved_sectors + cfg->rootdir_sectors;

        cfg->total_clusters = div_round_up(cfg->total_sectors - non_data_sectors_lb,
            cfg->sectors_per_cluster);

        if ((cfg->fat_type == FAT12 && cfg->total_clusters > FAT12_CLST_MAX) ||
            (cfg->fat_type == FAT16 && (cfg->total_clusters <= FAT12_CLST_MAX ||
            cfg->total_clusters > FAT16_CLST_MAX)) ||
            (cfg->fat_type == FAT32 && cfg->total_clusters <= FAT16_CLST_MAX))
                return ENOSPC;

        fat_bytes = div_round_up((cfg->total_clusters + 2) *
            FAT_CLUSTER_DOUBLE_SIZE(cfg->fat_type), 2);
        cfg->fat_sectors = div_round_up(fat_bytes, cfg->sector_size);

        return EOK;
}

/** Create file system with the given parameters. */
static int fat_blocks_write(struct fat_cfg const *cfg, service_id_t service_id)
{
        aoff64_t addr;
        uint8_t *buffer;
        int i;
        uint32_t j;
        int rc;
        struct fat_bs bs;

        fat_bootsec_create(cfg, &bs);

        rc = block_write_direct(service_id, BS_BLOCK, 1, &bs);
        if (rc != EOK)
                return EIO;

        addr = BS_BLOCK + 1;

        buffer = calloc(cfg->sector_size, 1);
        if (buffer == NULL)
                return ENOMEM;
        memset(buffer, 0, cfg->sector_size);

        /* Reserved sectors */
        for (i = 0; i < cfg->reserved_sectors - 1; ++i) {
                rc = block_write_direct(service_id, addr, 1, buffer);
                if (rc != EOK)
                        return EIO;

                ++addr;
        }

        /* File allocation tables */
        for (i = 0; i < cfg->fat_count; ++i) {
                printf("Writing allocation table %d.\n", i + 1);

                for (j = 0; j < cfg->fat_sectors; ++j) {
                        memset(buffer, 0, cfg->sector_size);
                        if (j == 0) {
                                buffer[0] = default_media_descriptor;
                                buffer[1] = 0xFF;
                                buffer[2] = 0xFF;
                                if (cfg->fat_type == FAT16) {
                                        buffer[3] = 0xFF;
                                } else if (cfg->fat_type == FAT32) {
                                        buffer[3] = 0x0F;
                                        buffer[4] = 0xFF;
                                        buffer[5] = 0xFF;
                                        buffer[6] = 0xFF;
                                        buffer[7] = 0x0F;
                                        buffer[8] = 0xF8;
                                        buffer[9] = 0xFF;
                                        buffer[10] = 0xFF;
                                        buffer[11] = 0x0F;
                                }
                        }

                        rc = block_write_direct(service_id, addr, 1, buffer);
                        if (rc != EOK)
                                return EIO;

                        ++addr;
                }
        }

        /* Root directory */
        printf("Writing root directory.\n");
        memset(buffer, 0, cfg->sector_size);
        if (cfg->fat_type != FAT32) {
                size_t idx;
                for (idx = 0; idx < cfg->rootdir_sectors; ++idx) {
                        rc = block_write_direct(service_id, addr, 1, buffer);
                        if (rc != EOK)
                                return EIO;

                        ++addr;
                }
        } else {
                for (i = 0; i < cfg->sectors_per_cluster; i++) {
                        rc = block_write_direct(service_id, addr, 1, buffer);
                        if (rc != EOK)
                                return EIO;

                        ++addr;
                }       
        }

        free(buffer);

        return EOK;
}

/** Construct boot sector with the given parameters. */
static void fat_bootsec_create(struct fat_cfg const *cfg, struct fat_bs *bs)
{
        memset(bs, 0, sizeof(*bs));

        bs->ji[0] = 0xEB;
        bs->ji[1] = 0x3C;
        bs->ji[2] = 0x90;

        memcpy(bs->oem_name, "HELENOS ", 8);

        /* BIOS Parameter Block */
        bs->bps = host2uint16_t_le(cfg->sector_size);
        bs->spc = cfg->sectors_per_cluster;
        bs->rscnt = host2uint16_t_le(cfg->reserved_sectors);
        bs->fatcnt = cfg->fat_count;
        bs->root_ent_max = host2uint16_t_le(cfg->root_ent_max);

        if (cfg->total_sectors < 0x10000) {
                bs->totsec16 = host2uint16_t_le(cfg->total_sectors);
                bs->totsec32 = 0;
        } else {
                bs->totsec16 = 0;
                bs->totsec32 = host2uint32_t_le(cfg->total_sectors);
        }

        bs->mdesc = default_media_descriptor;
        bs->sec_per_track = host2uint16_t_le(63);
        bs->signature = host2uint16_t_be(0x55AA);
        bs->headcnt = host2uint16_t_le(6);
        bs->hidden_sec = host2uint32_t_le(0);

        if (cfg->fat_type == FAT32) {
                bs->sec_per_fat = 0;
                bs->fat32.sectors_per_fat = host2uint32_t_le(cfg->fat_sectors);

                bs->fat32.pdn = 0x80;
                bs->fat32.ebs = 0x29;
                bs->fat32.id = host2uint32_t_be(0x12345678);
                bs->fat32.root_cluster = 2;

                memcpy(bs->fat32.label, "HELENOS_NEW", 11);
                memcpy(bs->fat32.type, "FAT32   ", 8);
        } else {
                bs->sec_per_fat = host2uint16_t_le(cfg->fat_sectors);
                bs->pdn = 0x80;
                bs->ebs = 0x29;
                bs->id = host2uint32_t_be(0x12345678);

                memcpy(bs->label, "HELENOS_NEW", 11);
                memcpy(bs->type, "FAT   ", 8);
        }
}

/**
 * @}
 */