Difference between versions 1.1.4 and 2.0.1

[gallegojm]

Hi Unless I am mistaken, when creating a file, without using the date/time callback function:

• version 1.1.4 set modification date and time to 2000-01-02 00:00 (as printed by printModifyDateTime) but
• version 2.0.1 (with SDFAT_FILE_TYPE set to 1) set modifyDate and modifyTime to 0 in the directory entry (printModifyDateTime print nothing) Is it intentional? This can be solved using the callback function, but I think it would be better to maintain compatibility, unless there is an other reason.

[greiman]

Setting date/time fields to zero was intentional. The FAT standard says if date and time fields are not supported, they should be set to 0 on file create and ignored on other file operations. Later versions say modify date and time must be supported but other fields may be zero.

Looks like I need to put a valid date time in the modify fields. Windows dir and Linux ls do strange things with zero.

I looked at FatFs and Chan uses 00:00:00 January 1 of the current year for the modify date time.

I looked at 1.1.4 and and default date/time is 2000-01-01 01:00.

/** Default date for file timestamps is 1 Jan 2000 */
const uint16_t FAT_DEFAULT_DATE = ((2000 - 1980) << 9) | (1 << 5) | 1;
/** Default time for file timestamp is 1 am */
const uint16_t FAT_DEFAULT_TIME = (1 << 11);

I think I will follow Chan, and use YYYY-01-01 00:00 where YYYY is the release year or maybe the compile year. I will leave the create and access fields zero.

[gallegojm]

Windows dir and Linux ls do strange things with zero.

Yes, and some programs too. For example FtpRush disconnect from server when listing a directory with files with zero in modify date time. Any date, 2000 or like Chan's solution, would fix this. Thank you for your help.

[greiman]

I added new code for default time stamps to the latest SdFat-beta version 2.0.2-beta.3. The values are defined in SdFatConfig.h. I will soon move this beta to the release version.

/**
 * Set the default file time stamp when a RTC callback is not used.
 * A valid date and time is required by the FAT/exFAT standard.
 *
 * The default below is YYYY-01-01 00:00:00 midnight where YYYY is
 * the compile year from the __DATE__ macro.  This is easy to recognize
 * as a placeholder for a correct date/time.
 *
 * The full compile date is:
 * FS_DATE(compileYear(), compileMonth(), compileDay())
 *
 * The full compile time is:
 * FS_TIME(compileHour(), compileMinute(), compileSecond())
 */
#define FS_DEFAULT_DATE FS_DATE(compileYear(), 1, 1)
/** 00:00:00 midnight */
#define FS_DEFAULT_TIME FS_TIME(0, 0, 0)

[gallegojm]

Hi Thank you for the fast update for setting and recovering date and time to files. My first test of FtpServer looks to work fine with SdFat-beta version 2.0.2-beta.3 At least with sd card using Fat16/32 files system. I need to purchase a card of larger capacity to try exFat, althougt not having the utility of files so large as 4 Giga

[greiman]

Thanks for the feedback. It helps me decide when to move a beta to the release repo.