/*
- * utils.c
- * exFAT file system implementation library.
- *
- * Created by Andrew Nayenko on 04.09.09.
- * This software is distributed under the GNU General Public License
- * version 3 or any later.
- */
+ utils.c (04.09.09)
+ exFAT file system implementation library.
+
+ Copyright (C) 2009, 2010 Andrew Nayenko
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
#include "exfat.h"
#include <string.h>
0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
};
-union exfat_date
-{
- uint16_t raw;
- struct
- {
- uint16_t day : 5; /* 1-31 */
- uint16_t month : 4; /* 1-12 */
- uint16_t year : 7; /* 1-127 (+1980) */
- };
-};
-
-union exfat_time
-{
- uint16_t raw;
- struct
- {
- uint16_t twosec : 5; /* 0-29 (2 sec granularity) */
- uint16_t min : 6; /* 0-59 */
- uint16_t hour : 5; /* 0-23 */
- };
-};
-
time_t exfat_exfat2unix(le16_t date, le16_t time)
{
- union exfat_date edate;
- union exfat_time etime;
time_t unix_time = EPOCH_DIFF_SEC;
+ uint16_t ndate = le16_to_cpu(date);
+ uint16_t ntime = le16_to_cpu(time);
+
+ uint16_t day = ndate & 0x1f; /* 5 bits, 1-31 */
+ uint16_t month = ndate >> 5 & 0xf; /* 4 bits, 1-12 */
+ uint16_t year = ndate >> 9; /* 7 bits, 1-127 (+1980) */
- edate.raw = le16_to_cpu(date);
- etime.raw = le16_to_cpu(time);
+ uint16_t twosec = ntime & 0x1f; /* 5 bits, 0-29 (2 sec granularity) */
+ uint16_t min = ntime >> 5 & 0xf; /* 6 bits, 0-59 */
+ uint16_t hour = ntime >> 11; /* 5 bits, 0-23 */
- if (edate.day == 0 || edate.month == 0 || edate.month > 12)
+ if (day == 0 || month == 0 || month > 12)
{
exfat_error("bad date %hu-%02hu-%02hu",
- edate.year + EXFAT_EPOCH_YEAR, edate.month, edate.day);
+ year + EXFAT_EPOCH_YEAR, month, day);
return 0;
}
- if (etime.hour > 23 || etime.min > 59 || etime.twosec > 29)
+ if (hour > 23 || min > 59 || twosec > 29)
{
exfat_error("bad time %hu:%02hu:%02hu",
- etime.hour, etime.min, etime.twosec * 2);
+ hour, min, twosec * 2);
return 0;
}
/* every 4th year between 1904 and 2096 is leap */
- unix_time += edate.year * SEC_IN_YEAR + LEAP_YEARS(edate.year) * SEC_IN_DAY;
- unix_time += days_in_year[edate.month] * SEC_IN_DAY;
+ unix_time += year * SEC_IN_YEAR + LEAP_YEARS(year) * SEC_IN_DAY;
+ unix_time += days_in_year[month] * SEC_IN_DAY;
/* if it's leap year and February has passed we should add 1 day */
- if ((EXFAT_EPOCH_YEAR + edate.year) % 4 == 0 && edate.month > 2)
+ if ((EXFAT_EPOCH_YEAR + year) % 4 == 0 && month > 2)
unix_time += SEC_IN_DAY;
- unix_time += (edate.day - 1) * SEC_IN_DAY;
+ unix_time += (day - 1) * SEC_IN_DAY;
- unix_time += etime.hour * SEC_IN_HOUR;
- unix_time += etime.min * SEC_IN_MIN;
+ unix_time += hour * SEC_IN_HOUR;
+ unix_time += min * SEC_IN_MIN;
/* exFAT represents time with 2 sec granularity */
- unix_time += etime.twosec * 2;
+ unix_time += twosec * 2;
/* exFAT stores timestamps in local time, so we correct it to UTC */
unix_time += timezone;
void exfat_unix2exfat(time_t unix_time, le16_t* date, le16_t* time)
{
- union exfat_date edate;
- union exfat_time etime;
time_t shift = EPOCH_DIFF_SEC + timezone;
+ uint16_t day, month, year;
+ uint16_t twosec, min, hour;
int days;
int i;
unix_time -= shift;
days = unix_time / SEC_IN_DAY;
- edate.year = (4 * days) / (4 * 365 + 1);
- days -= edate.year * 365 + LEAP_YEARS(edate.year);
+ year = (4 * days) / (4 * 365 + 1);
+ days -= year * 365 + LEAP_YEARS(year);
+ month = 0;
for (i = 1; i <= 12; i++)
{
- int leap_day = (IS_LEAP_YEAR(edate.year) && i == 2);
- int leap_sub = (IS_LEAP_YEAR(edate.year) && i >= 3);
+ int leap_day = (IS_LEAP_YEAR(year) && i == 2);
+ int leap_sub = (IS_LEAP_YEAR(year) && i >= 3);
if (i == 12 || days - leap_sub < days_in_year[i + 1] + leap_day)
{
- edate.month = i;
+ month = i;
days -= days_in_year[i] + leap_sub;
break;
}
}
- edate.day = days + 1;
+ day = days + 1;
- etime.hour = (unix_time % SEC_IN_DAY) / SEC_IN_HOUR;
- etime.min = (unix_time % SEC_IN_HOUR) / SEC_IN_MIN;
- etime.twosec = (unix_time % SEC_IN_MIN) / 2;
+ hour = (unix_time % SEC_IN_DAY) / SEC_IN_HOUR;
+ min = (unix_time % SEC_IN_HOUR) / SEC_IN_MIN;
+ twosec = (unix_time % SEC_IN_MIN) / 2;
- *date = cpu_to_le16(edate.raw);
- *time = cpu_to_le16(etime.raw);
+ *date = cpu_to_le16(day | (month << 5) | (year << 9));
+ *time = cpu_to_le16(twosec | (min << 5) | (hour << 11));
}
void exfat_get_name(const struct exfat_node* node, char* buffer, size_t n)
exfat_bug("failed to convert name to UTF-8");
}
-uint16_t exfat_start_checksum(const struct exfat_file* entry)
+uint16_t exfat_start_checksum(const struct exfat_entry_meta1* entry)
{
uint16_t sum = 0;
int i;
return sum;
}
-le16_t exfat_calc_checksum(const struct exfat_file* meta1,
- const struct exfat_file_info* meta2, const le16_t* name)
+le16_t exfat_calc_checksum(const struct exfat_entry_meta1* meta1,
+ const struct exfat_entry_meta2* meta2, const le16_t* name)
{
uint16_t checksum;
const int name_entries = DIV_ROUND_UP(utf16_length(name), EXFAT_ENAME_MAX);
checksum = exfat_add_checksum(meta2, checksum);
for (i = 0; i < name_entries; i++)
{
- struct exfat_file_name name_entry = {EXFAT_ENTRY_FILE_NAME, 0};
+ struct exfat_entry_name name_entry = {EXFAT_ENTRY_FILE_NAME, 0};
memcpy(name_entry.name, name + i * EXFAT_ENAME_MAX,
EXFAT_ENAME_MAX * sizeof(le16_t));
checksum = exfat_add_checksum(&name_entry, checksum);
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