/*===============================================================*\
| Project: RTEMS msdos format functionality |
+-----------------------------------------------------------------+
| File: msdos_format.c |
+-----------------------------------------------------------------+
| Copyright (c) 2004 IMD |
| Ingenieurbuero fuer Microcomputertechnik Th. Doerfler |
| <Thomas.Doerfler@imd-systems.de> |
| all rights reserved |
+-----------------------------------------------------------------+
| this file contains msdos_format function. This function |
| formats a disk partition conforming to MS-DOS conventions |
| |
| The license and distribution terms for this file may be |
| found in the file LICENSE in this distribution or at |
| http://www.rtems.com/license/LICENSE. |
| |
+-----------------------------------------------------------------+
| date history ID |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 29.10.04 creation doe |
\*===============================================================*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <assert.h>
#include <rtems/libio_.h>
#include "fat.h"
#include "fat_fat_operations.h"
#include "msdos.h"
#include "dosfs.h"
typedef struct {
uint32_t bytes_per_sector;
uint32_t totl_sector_cnt;
uint32_t rsvd_sector_cnt;
uint32_t sectors_per_cluster;
uint32_t sectors_per_fat;
uint32_t fat_start_sec;
uint32_t files_per_root_dir;
uint32_t root_dir_sectors;
uint32_t root_dir_start_sec;
uint32_t root_dir_fmt_sec_cnt;
uint32_t mbr_copy_sec; /* location of copy of mbr or 0 */
uint32_t fsinfo_sec; /* location of fsinfo sector or 0 */
uint8_t fat_num;
uint8_t media_code;
uint8_t fattype;
char OEMName[FAT_BR_OEMNAME_SIZE+1];
char VolLabel[FAT_BR_VOLLAB_SIZE+1];
bool VolLabel_present;
uint32_t vol_id;
} msdos_format_param_t;
/*
* Formatted output.
*/
static void
msdos_format_printf (const msdos_format_request_param_t *rqdata,
int info_level,
const char *format, ...)
{
va_list args;
va_start (args, format);
if (rqdata != NULL && rqdata->info_level >= info_level)
{
vfprintf (stdout, format, args);
fflush (stdout);
}
}
/*=========================================================================*\
| Function: |
\*-------------------------------------------------------------------------*/
static int msdos_format_read_sec
(
/*-------------------------------------------------------------------------*\
| Purpose: |
| function to read a sector |
+---------------------------------------------------------------------------+
| Input Parameters: |
\*-------------------------------------------------------------------------*/
int fd, /* file descriptor index */
uint32_t start_sector, /* sector number to write to */
uint32_t sector_size, /* size of sector */
char *buffer /* buffer with read data into */
)
/*-------------------------------------------------------------------------*\
| Return Value: |
| 0, if success, -1 and errno if failed |
\*=========================================================================*/
{
int ret_val = 0;
if (0 > lseek(fd,((off_t)start_sector)*sector_size,SEEK_SET)) {
ret_val = -1;
}
if (ret_val == 0) {
if (0 > read(fd,buffer,sector_size)) {
ret_val = -1;
}
}
return ret_val;
}
/*=========================================================================*\
| Function: |
\*-------------------------------------------------------------------------*/
static int msdos_format_write_sec
(
/*-------------------------------------------------------------------------*\
| Purpose: |
| function to write to a sector |
+---------------------------------------------------------------------------+
| Input Parameters: |
\*-------------------------------------------------------------------------*/
int fd, /* file descriptor index */
uint32_t start_sector, /* sector number to write to */
uint32_t sector_size, /* size of sector */
const char *buffer /* buffer with write data */
)
/*-------------------------------------------------------------------------*\
| Return Value: |
| 0, if success, -1 and errno if failed |
\*=========================================================================*/
{
int ret_val = 0;
if (0 > lseek(fd,((off_t)start_sector)*sector_size,SEEK_SET)) {
ret_val = -1;
}
if (ret_val == 0) {
if (0 > write(fd,buffer,sector_size)) {
ret_val = -1;
}
}
return ret_val;
}
/*=========================================================================* \
| Function: |
\*-------------------------------------------------------------------------*/
static int msdos_format_fill_sectors
(
/*-------------------------------------------------------------------------*\
| Purpose: |
| function to fill sectors with byte |
+---------------------------------------------------------------------------+
| Input Parameters: |
\*-------------------------------------------------------------------------*/
const msdos_format_request_param_t *rqdata,
int fd, /* file descriptor index */
uint32_t start_sector, /* sector number to fill to */
uint32_t sector_cnt, /* number of sectors to fill to */
uint32_t sector_size, /* size of sector */
const char fill_byte /* byte to fill into sectors */
)
/*-------------------------------------------------------------------------*\
| Return Value: |
| 0, if success, -1 and errno if failed |
\*=========================================================================*/
{
int ret_val = 0;
char *fill_buffer = NULL;
uint32_t total_sectors = sector_cnt;
int last_percent = -1;
/*
* allocate and fill buffer
*/
if (ret_val == 0) {
fill_buffer = malloc(sector_size);
if (fill_buffer == NULL) {
errno = ENOMEM;
ret_val = -1;
}
else {
memset(fill_buffer,fill_byte,sector_size);
}
}
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL,
"Filling : ");
/*
* write to consecutive sectors
*/
while ((ret_val == 0) &&
(sector_cnt > 0)) {
int percent = (sector_cnt * 100) / total_sectors;
if (percent != last_percent) {
if ((percent & 1) == 0)
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL, ".");
last_percent = percent;
}
ret_val = msdos_format_write_sec(fd,start_sector,sector_size,fill_buffer);
start_sector++;
sector_cnt--;
}
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL, "\n");
if (ret_val)
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_INFO,
"filling error on sector: %d\n", start_sector);
/*
* cleanup
*/
if (fill_buffer != NULL) {
free(fill_buffer);
fill_buffer = NULL;
}
return ret_val;
}
/*=========================================================================*\
| Function: |
\*-------------------------------------------------------------------------*/
static int msdos_format_gen_volid
(
/*-------------------------------------------------------------------------*\
| Purpose: |
| function to generate a pseudo-random volume id |
+---------------------------------------------------------------------------+
| Input Parameters: |
\*-------------------------------------------------------------------------*/
uint32_t *volid_ptr /* volume ID return pointer */
)
/*-------------------------------------------------------------------------*\
| Return Value: |
| 0, if success, -1 and errno if failed |
\*=========================================================================*/
{
int ret_val = 0;
int rc;
rtems_clock_time_value time_value;
rc = rtems_clock_get(RTEMS_CLOCK_GET_TIME_VALUE,&time_value);
if (rc == RTEMS_SUCCESSFUL) {
*volid_ptr = time_value.seconds + time_value.microseconds;
}
else {
*volid_ptr = rand();
}
return ret_val;
}
/*=========================================================================*\
| Function: |
\*-------------------------------------------------------------------------*/
static int msdos_format_eval_sectors_per_cluster
(
/*-------------------------------------------------------------------------*\
| Purpose: |
| function to check/adjust sectors_per_cluster to legal values |
+---------------------------------------------------------------------------+
| Input Parameters: |
\*-------------------------------------------------------------------------*/
int fattype, /* type code of FAT (FAT_FAT12 ...) */
uint32_t bytes_per_sector, /* byte count per sector (512) */
uint32_t fatdata_sec_cnt, /* sectors available for FAT and data */
uint8_t fat_num, /* number of fat copies */
uint32_t sectors_per_cluster, /* sectors per cluster (requested) */
uint32_t *sectors_per_cluster_adj, /* ret: sec per cluster (granted) */
uint32_t *sectors_per_fat_ptr /* ret: sectors needed for one FAT */
)
/*-------------------------------------------------------------------------*\
| Return Value: |
| 0, if success, -1 and errno if failed |
\*=========================================================================*/
{
bool finished = false;
int ret_val = 0;
uint32_t fatdata_cluster_cnt;
uint32_t fat_capacity;
uint32_t sectors_per_fat;
uint32_t data_cluster_cnt;
/*
* ensure, that maximum cluster size (32KByte) is not exceeded
*/
while (MS_BYTES_PER_CLUSTER_LIMIT / bytes_per_sector < sectors_per_cluster) {
sectors_per_cluster /= 2;
}
do {
/*
* compute number of data clusters for current data:
* - compute cluster count for data AND fat
* - compute storage size for FAT
* - subtract from total cluster count
*/
fatdata_cluster_cnt = fatdata_sec_cnt/sectors_per_cluster;
if (fattype == FAT_FAT12) {
fat_capacity = fatdata_cluster_cnt * 3 / 2;
}
else if (fattype == FAT_FAT16) {
fat_capacity = fatdata_cluster_cnt * 2;
}
else { /* FAT32 */
fat_capacity = fatdata_cluster_cnt * 4;
}
sectors_per_fat = ((fat_capacity
+ (bytes_per_sector - 1))
/ bytes_per_sector);
data_cluster_cnt = (fatdata_cluster_cnt -
(((sectors_per_fat * fat_num)
+ (sectors_per_cluster - 1))
/ sectors_per_cluster));
/*
* data cluster count too big? then make sectors bigger
*/
if (((fattype == FAT_FAT12) && (data_cluster_cnt > FAT_FAT12_MAX_CLN)) ||
((fattype == FAT_FAT16) && (data_cluster_cnt > FAT_FAT16_MAX_CLN))) {
sectors_per_cluster *= 2;
}
else {
finished = true;
}
/*
* when maximum cluster size is exceeded, we have invalid data, abort...
*/
if ((sectors_per_cluster * bytes_per_sector)
> MS_BYTES_PER_CLUSTER_LIMIT) {
ret_val = EINVAL;
finished = true;
}
} while (!finished);
if (ret_val != 0) {
rtems_set_errno_and_return_minus_one(ret_val);
}
else {
*sectors_per_cluster_adj = sectors_per_cluster;
*sectors_per_fat_ptr = sectors_per_fat;
return 0;
}
}
/*=========================================================================*\
| Function: |
\*-------------------------------------------------------------------------*/
static int msdos_format_determine_fmt_params
(
/*-------------------------------------------------------------------------*\
| Purpose: |
| determine parameters for formatting |
+---------------------------------------------------------------------------+
| Input Parameters: |
\*-------------------------------------------------------------------------*/
const rtems_disk_device *dd, /* disk device structure */
const msdos_format_request_param_t *rqdata, /* requested fmt parameters */
msdos_format_param_t *fmt_params/* computed fmt parameters */
)
/*-------------------------------------------------------------------------*\
| Return Value: |
| 0, if success, -1 and errno if failed |
\*=========================================================================*/
{
int ret_val = 0;
uint32_t fatdata_sect_cnt;
uint32_t onebit;
uint32_t sectors_per_cluster_adj = 0;
uint64_t total_size = 0;
memset(fmt_params,0,sizeof(*fmt_params));
/*
* this one is fixed in this implementation.
* At least one thing we don't have to magically guess...
*/
if (ret_val == 0) {
fmt_params->bytes_per_sector = dd->block_size;
fmt_params->totl_sector_cnt = dd->size;
total_size = dd->block_size * dd->size;
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL,
"bytes per sector: %d\ntotal sectors: %d\ntotal size: %lu\n",
dd->block_size, dd->size, total_size);
}
/*
* determine number of FATs
*/
if (ret_val == 0) {
if ((rqdata == NULL) ||
(rqdata->fat_num == 0)) {
fmt_params->fat_num = 2;
}
else if (rqdata->fat_num <= 6) {
fmt_params->fat_num = rqdata->fat_num;
}
else {
ret_val = EINVAL;
}
}
if (ret_val == 0)
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL,
"number of fats: %d\n", fmt_params->fat_num);
/*
* Now we get sort of a loop when determining things:
* The FAT type (FAT12/16/32) is determined ONLY from the
* data cluster count:
* Disks with data cluster count < 4085 are FAT12.
* Disks with data cluster count < 65525 are FAT16.
* The rest is FAT32 (no FAT128 available yet :-)
*
* The number of data clusters is the
* total capacity
* minus reserved sectors
* minus root directory ares
* minus storage needed for the FAT (and its copy/copies).
*
* The last item once again depends on the FAT type and the cluster count.
*
* So here is what we do in this formatter:
* - If a FAT type is requested from the caller, we try to modify
* the cluster size, until the data cluster count is in range
* - If no FAT type is given, we estimate a useful FAT type from
* the disk capacity and then adapt the cluster size
*/
/*
* determine characteristic values:
* - number of sectors
* - number of reserved sectors
* - number of used sectors
* - sectors per cluster
*/
/*
* determine FAT type and sectors per cluster
* depends on
*/
if (ret_val == 0) {
fmt_params->sectors_per_cluster = 1;
if ((rqdata != NULL) &&
(rqdata->fattype == MSDOS_FMT_FAT12)) {
fmt_params->fattype = FAT_FAT12;
}
else if ((rqdata != NULL) &&
(rqdata->fattype == MSDOS_FMT_FAT16)) {
fmt_params->fattype = FAT_FAT16;
}
else if ((rqdata != NULL) &&
(rqdata->fattype == MSDOS_FMT_FAT32)) {
fmt_params->fattype = FAT_FAT32;
}
else if ((rqdata != NULL) &&
(rqdata->fattype != MSDOS_FMT_FATANY)) {
ret_val = -1;
errno = EINVAL;
}
else {
/*
* limiting values for disk size, fat type, sectors per cluster
* NOTE: maximum sect_per_clust is arbitrarily choosen with values that
* are a compromise concerning capacity and efficency
*/
if (fmt_params->totl_sector_cnt
< ((uint32_t)FAT_FAT12_MAX_CLN)*8) {
fmt_params->fattype = FAT_FAT12;
/* start trying with small clusters */
fmt_params->sectors_per_cluster = 2;
}
else if (fmt_params->totl_sector_cnt
< ((uint32_t)FAT_FAT16_MAX_CLN)*32) {
fmt_params->fattype = FAT_FAT16;
/* start trying with small clusters */
fmt_params->sectors_per_cluster = 2;
}
else {
uint32_t gigs = (total_size + (1024 * 1024 * 1024)) / (1024 * 1024 * 1024);
int b;
fmt_params->fattype = FAT_FAT32;
/* scale with the size of disk... */
for (b = 31; b > 0; b--)
if ((gigs & (1 << b)) != 0)
break;
fmt_params->sectors_per_cluster = 1 << b;
}
}
/*
* try to use user requested cluster size
*/
if ((rqdata != NULL) &&
(rqdata->sectors_per_cluster > 0)) {
fmt_params->sectors_per_cluster =
rqdata->sectors_per_cluster;
}
/*
* check sectors per cluster.
* must be power of 2
* must be smaller than or equal to 128
* sectors_per_cluster*bytes_per_sector must not be bigger than 32K
*/
for (onebit = 128;onebit >= 1;onebit = onebit>>1) {
if (fmt_params->sectors_per_cluster >= onebit) {
fmt_params->sectors_per_cluster = onebit;
if (fmt_params->sectors_per_cluster
<= 32768L/fmt_params->bytes_per_sector) {
/* value is small enough so this value is ok */
onebit = 1;
}
}
}
}
if (ret_val == 0) {
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL,
"sectors per cluster: %d\n", fmt_params->sectors_per_cluster);
if (fmt_params->fattype == FAT_FAT32) {
/* recommended: for FAT32, always set reserved sector count to 32 */
fmt_params->rsvd_sector_cnt = 32;
/* for FAT32, always set files per root directory 0 */
fmt_params->files_per_root_dir = 0;
/* location of copy of MBR */
fmt_params->mbr_copy_sec = 6;
/* location of fsinfo sector */
fmt_params->fsinfo_sec = 1;
}
else {
/* recommended: for FAT12/FAT16, always set reserved sector count to 1 */
fmt_params->rsvd_sector_cnt = 1;
/* recommended: for FAT16, set files per root directory to 512 */
/* for FAT12/FAT16, set files per root directory */
/* must fill up an even count of sectors */
if ((rqdata != NULL) &&
(rqdata->files_per_root_dir > 0)) {
fmt_params->files_per_root_dir = rqdata->files_per_root_dir;
}
else {
if (fmt_params->fattype == FAT_FAT16) {
fmt_params->files_per_root_dir = 512;
}
else {
fmt_params->files_per_root_dir = 64;
}
}
fmt_params->files_per_root_dir = (fmt_params->files_per_root_dir +
(2*fmt_params->bytes_per_sector/
FAT_DIRENTRY_SIZE-1));
fmt_params->files_per_root_dir -= (fmt_params->files_per_root_dir %
(2*fmt_params->bytes_per_sector
/FAT_DIRENTRY_SIZE));
}
fmt_params->root_dir_sectors =
(((fmt_params->files_per_root_dir * FAT_DIRENTRY_SIZE)
+ fmt_params->bytes_per_sector - 1)
/ fmt_params->bytes_per_sector);
}
if (ret_val == 0) {
fatdata_sect_cnt = (fmt_params->totl_sector_cnt -
fmt_params->rsvd_sector_cnt -
fmt_params->root_dir_sectors);
/*
* check values to get legal arrangement of FAT type and cluster count
*/
ret_val = msdos_format_eval_sectors_per_cluster
(fmt_params->fattype,
fmt_params->bytes_per_sector,
fatdata_sect_cnt,
fmt_params->fat_num,
fmt_params->sectors_per_cluster,
§ors_per_cluster_adj,
&(fmt_params->sectors_per_fat));
fmt_params->sectors_per_cluster = sectors_per_cluster_adj;
}
/*
* determine media code
*/
if (ret_val == 0) {
if ((rqdata != NULL) &&
(rqdata->media != 0)) {
const char valid_media_codes[] =
{0xF0,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF};
if (NULL==memchr(valid_media_codes,
rqdata->media,
sizeof(valid_media_codes))) {
ret_val = -1;
errno = EINVAL;
}
else {
fmt_params->media_code = rqdata->media;
}
}
else {
fmt_params->media_code = FAT_BR_MEDIA_FIXED;
}
}
/*
* determine location and size of root directory
* for formatting
*/
if (fmt_params->root_dir_sectors > 0) {
fmt_params->root_dir_start_sec =
fmt_params->rsvd_sector_cnt
+ (fmt_params-> fat_num*fmt_params->sectors_per_fat);
fmt_params->root_dir_fmt_sec_cnt = fmt_params->root_dir_sectors;
}
else {
/*
* for FAT32: root directory is in cluster 2
*/
fmt_params->root_dir_start_sec =
fmt_params->rsvd_sector_cnt
+ (fmt_params-> fat_num*fmt_params->sectors_per_fat);
fmt_params->root_dir_fmt_sec_cnt = fmt_params->sectors_per_cluster;
}
/*
* determine usable OEMName
*/
if (ret_val == 0) {
const char *from;
char *to = fmt_params->OEMName;
int cnt;
from = "RTEMS"; /* default: make "from" point to OS Name */
if ((rqdata != NULL) &&
(rqdata->OEMName != NULL)) {
from = rqdata->OEMName;
}
for (cnt = 0;
cnt < (sizeof(fmt_params->OEMName)-1);
cnt++) {
if (isprint(*from)) {
*to++ = *from++;
}
else {
/*
* non-printable character in given name, so keep stuck
* at that character and replace all following characters
* with a ' '
*/
*to++=' ';
}
*to = '\0';
}
}
/*
* determine usable Volume Label
*/
if (ret_val == 0) {
const char *from;
char *to = fmt_params->VolLabel;
int cnt;
from = ""; /* default: make "from" point to empty string */
if ((rqdata != NULL) &&
(rqdata->VolLabel != NULL)) {
from = rqdata->VolLabel;
fmt_params->VolLabel_present = true;
}
for (cnt = 0;
cnt < (sizeof(fmt_params->VolLabel)-1);
cnt++) {
if (isprint(*from)) {
*to++ = *from++;
}
else {
/*
* non-printable character in given name, so keep stuck
* at that character and replace all following characters
* with a ' '
*/
*to++=' ';
}
*to = '\0';
}
}
/*
* determine usable Volume ID
*/
if (ret_val == 0) {
msdos_format_gen_volid(&(fmt_params->vol_id));
}
/*
* Phuuu.... That's it.
*/
if (ret_val != 0) {
rtems_set_errno_and_return_minus_one(ret_val);
}
else {
return 0;
}
}
/*=========================================================================*\
| Function: |
\*-------------------------------------------------------------------------*/
static int msdos_format_gen_mbr
(
/*-------------------------------------------------------------------------*\
| Purpose: |
| create master boot record content from parameter set |
+---------------------------------------------------------------------------+
| Input Parameters: |
\*-------------------------------------------------------------------------*/
char mbr[], /* sector buffer */
const msdos_format_param_t *fmt_params/* computed fmt parameters */
)
/*-------------------------------------------------------------------------*\
| Return Value: |
| 0, if success, -1 and errno if failed |
\*=========================================================================*/
{
uint32_t total_sectors_num16 = 0;
uint32_t total_sectors_num32 = 0;
/* store total sector count in either 16 or 32 bit field in mbr */
if (fmt_params->totl_sector_cnt < 0x10000) {
total_sectors_num16 = fmt_params->totl_sector_cnt;
}
else {
total_sectors_num32 = fmt_params->totl_sector_cnt;
}
/*
* finally we are there: let's fill in the values into the MBR
* but first clear the MRB leaving the partition table.
*/
#define RTEMS_IDE_PARTITION_TABLE_OFFSET 0x1be
#define RTEMS_IDE_PARTITION_TABLE_SIZE (4 * 16)
memset(mbr,0,RTEMS_IDE_PARTITION_TABLE_OFFSET);
memset(mbr + RTEMS_IDE_PARTITION_TABLE_OFFSET + RTEMS_IDE_PARTITION_TABLE_SIZE,
0,
FAT_TOTAL_MBR_SIZE - (RTEMS_IDE_PARTITION_TABLE_OFFSET + RTEMS_IDE_PARTITION_TABLE_SIZE));
/*
* FIXME: fill jmpBoot and Boot code...
* with 0xEB,....
*/
/*
* fill OEMName
*/
memcpy(FAT_GET_ADDR_BR_OEMNAME(mbr),
fmt_params->OEMName,
FAT_BR_OEMNAME_SIZE);
FAT_SET_BR_BYTES_PER_SECTOR(mbr , fmt_params->bytes_per_sector);
FAT_SET_BR_SECTORS_PER_CLUSTER(mbr , fmt_params->sectors_per_cluster);
FAT_SET_BR_RESERVED_SECTORS_NUM(mbr, fmt_params->rsvd_sector_cnt);
/* number of FATs on medium */
FAT_SET_BR_FAT_NUM(mbr , 2); /* standard/recommended value */
FAT_SET_BR_FILES_PER_ROOT_DIR(mbr , fmt_params->files_per_root_dir);
FAT_SET_BR_TOTAL_SECTORS_NUM16(mbr , total_sectors_num16);
FAT_SET_BR_MEDIA(mbr , fmt_params->media_code);
FAT_SET_BR_SECTORS_PER_TRACK(mbr , 255); /* only needed for INT13... */
FAT_SET_BR_NUMBER_OF_HEADS(mbr , 6); /* only needed for INT13... */
FAT_SET_BR_HIDDEN_SECTORS(mbr , 1); /* only needed for INT13... */
FAT_SET_BR_TOTAL_SECTORS_NUM32(mbr , total_sectors_num32);
if (fmt_params->fattype != FAT_FAT32) {
FAT_SET_BR_SECTORS_PER_FAT(mbr ,fmt_params->sectors_per_fat);
FAT_SET_BR_DRVNUM(mbr , 0); /* only needed for INT13... */
FAT_SET_BR_RSVD1(mbr , 0); /* fill with zero */
FAT_SET_BR_BOOTSIG(mbr , FAT_BR_BOOTSIG_VAL);
FAT_SET_BR_VOLID(mbr , fmt_params->vol_id); /* volume id */
memcpy(FAT_GET_ADDR_BR_VOLLAB(mbr),
fmt_params->VolLabel,
FAT_BR_VOLLAB_SIZE);
memcpy(FAT_GET_ADDR_BR_FILSYSTYPE(mbr),
(fmt_params->fattype == FAT_FAT12)
? "FAT12 "
: "FAT16 ",
FAT_BR_FILSYSTYPE_SIZE);
}
else {
FAT_SET_BR_SECTORS_PER_FAT32(mbr ,fmt_params->sectors_per_fat);
FAT_SET_BR_EXT_FLAGS(mbr , 0);
FAT_SET_BR_FSVER(mbr , 0); /* FAT32 Version:0.0 */
FAT_SET_BR_FAT32_ROOT_CLUSTER(mbr , 2); /* put root dir to cluster 2 */
FAT_SET_BR_FAT32_FS_INFO_SECTOR(mbr, 1); /* Put fsinfo to rsrvd sec 1*/
FAT_SET_BR_FAT32_BK_BOOT_SECTOR(mbr, fmt_params->mbr_copy_sec ); /* Put MBR copy to rsrvd sec */
memset(FAT_GET_ADDR_BR_FAT32_RESERVED(mbr),0,FAT_BR_FAT32_RESERVED_SIZE);
FAT_SET_BR_FAT32_DRVNUM(mbr , 0); /* only needed for INT13... */
FAT_SET_BR_FAT32_RSVD1(mbr , 0); /* fill with zero */
FAT_SET_BR_FAT32_BOOTSIG(mbr ,FAT_BR_FAT32_BOOTSIG_VAL);
FAT_SET_BR_FAT32_VOLID(mbr , 0); /* not set */
memset(FAT_GET_ADDR_BR_FAT32_VOLLAB(mbr) ,0,FAT_BR_VOLLAB_SIZE);
memcpy(FAT_GET_ADDR_BR_FAT32_FILSYSTYPE(mbr),
"FAT32 ",
FAT_BR_FILSYSTYPE_SIZE);
}
/*
* add boot record signature
*/
FAT_SET_BR_SIGNATURE(mbr, FAT_BR_SIGNATURE_VAL);
/*
* add jump to boot loader at start of sector
*/
FAT_SET_VAL8(mbr,0,0xeb);
FAT_SET_VAL8(mbr,1,0x3c);
FAT_SET_VAL8(mbr,2,0x90);
/*
* FIXME: a nice little PC boot loader would be nice here.
* but where can I get one for free?
*/
/*
* Phuuu.... That's it.
*/
return 0;
}
/*=========================================================================*\
| Function: |
\*-------------------------------------------------------------------------*/
static int msdos_format_gen_fsinfo
(
/*-------------------------------------------------------------------------*\
| Purpose: |
| create FAT32 fsinfo sector |
+---------------------------------------------------------------------------+
| Input Parameters: |
\*-------------------------------------------------------------------------*/
char fsinfo[] /* sector buffer */
)
/*-------------------------------------------------------------------------*\
| Return Value: |
| 0, if success, -1 and errno if failed |
\*=========================================================================*/
{
/*
* clear fsinfo sector data
*/
memset(fsinfo,0,FAT_TOTAL_FSINFO_SIZE);
/*
* write LEADSIG, STRUCTSIG, TRAILSIG
*/
FAT_SET_FSINFO_LEAD_SIGNATURE (fsinfo,FAT_FSINFO_LEAD_SIGNATURE_VALUE );
FAT_SET_FSINFO_STRUC_SIGNATURE(fsinfo,FAT_FSINFO_STRUC_SIGNATURE_VALUE);
FAT_SET_FSINFO_TRAIL_SIGNATURE(fsinfo,FAT_FSINFO_TRAIL_SIGNATURE_VALUE);
/*
* write "empty" values for free cluster count and next cluster number
*/
FAT_SET_FSINFO_FREE_CLUSTER_COUNT(fsinfo+FAT_FSI_INFO,
0xffffffff);
FAT_SET_FSINFO_NEXT_FREE_CLUSTER (fsinfo+FAT_FSI_INFO,
0xffffffff);
return 0;
}
/*=========================================================================*\
| Function: |
\*-------------------------------------------------------------------------*/
int msdos_format
(
/*-------------------------------------------------------------------------*\
| Purpose: |
| format device with msdos filesystem |
+---------------------------------------------------------------------------+
| Input Parameters: |
\*-------------------------------------------------------------------------*/
const char *devname, /* device name */
const msdos_format_request_param_t *rqdata /* requested fmt parameters */
/* set to NULL for automatic */
/* determination */
)
/*-------------------------------------------------------------------------*\
| Return Value: |
| 0, if success, -1 and errno if failed |
\*=========================================================================*/
{
char tmp_sec[FAT_TOTAL_MBR_SIZE];
int rc;
rtems_disk_device *dd = NULL;
struct stat stat_buf;
int ret_val = 0;
int fd = -1;
int i;
msdos_format_param_t fmt_params;
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_INFO,
"formating: %s\n", devname);
/*
* sanity check on device
*/
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL,
"stat check: %s\n", devname);
if (ret_val == 0) {
rc = stat(devname, &stat_buf);
ret_val = rc;
}
/* rtems feature: no block devices, all are character devices */
if ((ret_val == 0) &&
(!S_ISCHR(stat_buf.st_mode))) {
errno = ENOTBLK;
ret_val = -1;
}
/* check that device is registered as block device and lock it */
if (ret_val == 0) {
dd = rtems_disk_obtain(stat_buf.st_rdev);
if (dd == NULL) {
errno = ENOTBLK;
ret_val = -1;
}
}
/*
* open device for writing
*/
if (ret_val == 0) {
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL,
"open device\n");
fd = open(devname, O_RDWR);
if (fd == -1)
{
ret_val= -1;
}
}
/*
* compute formatting parameters
*/
if (ret_val == 0) {
ret_val = msdos_format_determine_fmt_params(dd,rqdata,&fmt_params);
}
/*
* if requested, write whole disk/partition with 0xe5
*/
if ((ret_val == 0) &&
(rqdata != NULL) &&
!(rqdata->quick_format)) {
ret_val = msdos_format_fill_sectors
(rqdata,
fd,
0, /* start sector */
fmt_params.totl_sector_cnt, /* sector count */
fmt_params.bytes_per_sector,
0xe5);
}
/*
* create master boot record
*/
if (ret_val == 0) {
/*
* Read the current MBR to obtain the partition table.
*/
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL,
"read MRB sector\n");
ret_val = msdos_format_read_sec(fd,
0,
fmt_params.bytes_per_sector,
tmp_sec);
if (ret_val == 0) {
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL,
"generate MRB sector\n");
ret_val = msdos_format_gen_mbr(tmp_sec,&fmt_params);
}
/*
* write master boot record to disk
* also write copy of MBR to disk
*/
if (ret_val == 0) {
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL,
"write MRB sector\n");
ret_val = msdos_format_write_sec(fd,
0,
fmt_params.bytes_per_sector,
tmp_sec);
}
if ((ret_val == 0) &&
(fmt_params.mbr_copy_sec != 0)) {
/*
* write copy of MBR
*/
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL,
"write back up MRB sector\n");
ret_val = msdos_format_write_sec(fd,
fmt_params.mbr_copy_sec ,
fmt_params.bytes_per_sector,
tmp_sec);
}
}
/*
* for FAT32: initialize info sector on disk
*/
if ((ret_val == 0) &&
(fmt_params.fsinfo_sec != 0)) {
ret_val = msdos_format_gen_fsinfo(tmp_sec);
}
/*
* write fsinfo sector
*/
if ((ret_val == 0) &&
(fmt_params.fsinfo_sec != 0)) {
ret_val = msdos_format_write_sec(fd,
fmt_params.fsinfo_sec,
fmt_params.bytes_per_sector,
tmp_sec);
}
/*
* write FAT as all empty
* -> write all FAT sectors as zero
*/
if (ret_val == 0) {
ret_val = msdos_format_fill_sectors
(rqdata,
fd,
fmt_params.rsvd_sector_cnt, /* start sector */
fmt_params.fat_num*fmt_params.sectors_per_fat,/* sector count */
fmt_params.bytes_per_sector,
0x00);
}
/*
* clear/init root directory
* -> write all directory sectors as 0x00
*/
if (ret_val == 0) {
ret_val = msdos_format_fill_sectors
(rqdata,
fd,
fmt_params.root_dir_start_sec, /* start sector */
fmt_params.root_dir_fmt_sec_cnt, /* sector count */
fmt_params.bytes_per_sector,
0x00);
}
/*
* write volume label to first entry of directory
*/
if ((ret_val == 0) && fmt_params.VolLabel_present) {
memset(tmp_sec,0,sizeof(tmp_sec));
memcpy(MSDOS_DIR_NAME(tmp_sec),fmt_params.VolLabel,MSDOS_SHORT_NAME_LEN);
*MSDOS_DIR_ATTR(tmp_sec) = MSDOS_ATTR_VOLUME_ID;
ret_val = msdos_format_write_sec
(fd,
fmt_params.root_dir_start_sec,
fmt_params.bytes_per_sector,
tmp_sec);
}
/*
* write FAT entry 0 as (0xffffff00|Media_type)EOC,
* write FAT entry 1 as EOC
* allocate directory in a FAT32 FS
*/
if ((ret_val == 0) && fmt_params.VolLabel_present){
/*
* empty sector: all clusters are free/do not link further on
*/
memset(tmp_sec,0,sizeof(tmp_sec));
switch(fmt_params.fattype) {
case FAT_FAT12:
/* LSBits of FAT entry 0: media_type */
FAT_SET_VAL8(tmp_sec,0,(fmt_params.media_code));
/* MSBits of FAT entry 0:0xf, LSBits of FAT entry 1: LSB of EOC */
FAT_SET_VAL8(tmp_sec,1,(0x0f | (FAT_FAT12_EOC << 4)));
/* MSBits of FAT entry 1: MSBits of EOC */
FAT_SET_VAL8(tmp_sec,2,(FAT_FAT12_EOC >> 4));
break;
case FAT_FAT16:
/* FAT entry 0: 0xff00|media_type */
FAT_SET_VAL16(tmp_sec,0,0xff00|fmt_params.media_code);
/* FAT entry 1: EOC */
FAT_SET_VAL16(tmp_sec,2,FAT_FAT16_EOC);
break;
case FAT_FAT32:
/* FAT entry 0: 0xffffff00|media_type */
FAT_SET_VAL32(tmp_sec,0,0xffffff00|fmt_params.media_code);
/* FAT entry 1: EOC */
FAT_SET_VAL32(tmp_sec,4,FAT_FAT32_EOC);
break;
default:
ret_val = -1;
errno = EINVAL;
}
if (fmt_params.fattype == FAT_FAT32) {
/*
* only first valid cluster (cluster number 2) belongs
* to root directory, and is end of chain
* mark this in every copy of the FAT
*/
FAT_SET_VAL32(tmp_sec,8,FAT_FAT32_EOC);
}
for (i = 0;
(i < fmt_params.fat_num) && (ret_val == 0);
i++) {
ret_val = msdos_format_write_sec
(fd,
fmt_params.rsvd_sector_cnt
+ (i * fmt_params.sectors_per_fat),
fmt_params.bytes_per_sector,
tmp_sec);
}
}
/*
* cleanup:
* sync and unlock disk
* free any data structures (not needed now)
*/
if (fd != -1) {
close(fd);
}
if (dd != NULL) {
rtems_disk_release(dd);
}
return ret_val;
}
