| Matt Mower | 18794c8 | 2015-11-11 16:22:45 -0600 | [diff] [blame^] | 1 | mkdosfs - Make DOS filesystem utilty. |
| bigbiff bigbiff | 9c75405 | 2013-01-09 09:09:08 -0500 | [diff] [blame] | 2 | |
| 3 | |
| 4 | I wrote this, partially to complement the dosfsck utility written by Werner |
| 5 | Almesberger (who graciously gave me some pointers when I asked for some |
| 6 | advice about writing this code), and also to avoid me having to boot DOS |
| 7 | just to create data partitions (I use Linux to back up DOS :-) ). |
| 8 | |
| 9 | The code is really derived from Remy Card's mke2fs utility - I used this as a |
| Matt Mower | 18794c8 | 2015-11-11 16:22:45 -0600 | [diff] [blame^] | 10 | framework, although all of the filesystem specific stuff was removed and the |
| bigbiff bigbiff | 9c75405 | 2013-01-09 09:09:08 -0500 | [diff] [blame] | 11 | DOS stuff inserted. I believe originally mke2fs was based on Linus' mkfs |
| 12 | code, hence the acknowledgements in the source code. |
| 13 | |
| 14 | Neither Remy nor Linus have had any involvement with mkdosfs, so if there are |
| 15 | any bugs they're almost certainly "all my own work". |
| 16 | |
| 17 | The code has been available for ftp since 1st September 1993, and I have yet |
| 18 | to receive any bug reports from users. I don't know of any bugs, but if you |
| 19 | do find a bug or have any constructive comments, please mail me! |
| 20 | |
| 21 | The only bug I found with version 0.1 was an obscure fault that could lead |
| 22 | to an invalid (for MS-DOS, not Linux's dos fs) number of sectors used in the |
| 23 | file allocation table(s). |
| 24 | |
| 25 | |
| 26 | Dave Hudson |
| 27 | dave@humbug.demon.co.uk |
| 28 | |
| 29 | |
| 30 | FAT32 support |
| 31 | ============= |
| 32 | |
| 33 | mkdosfs now can also create filesystems in the new FAT32 format. To do |
| 34 | this, give mkdosfs a "-F 32" option. FAT32 isn't selected |
| 35 | automatically (yet), even if very large clusters are needed with |
| 36 | FAT16. With FAT32 you have two additional options, -R to select the |
| 37 | number of reserved sectors (usually 32), and -b to select the location |
| 38 | of the backup boot sector (default 6). Of course such a backup is |
| 39 | created, as well as the new info sector. On FAT32, the root directory |
| 40 | is always created as a cluster chain. Sorry, there's no switch to |
| 41 | generate an old static root dir. |
| 42 | |
| 43 | One bigger bug fix besides FAT32 was to reject filesystems that need a |
| 44 | 16 bit FAT to fit all possible clusters, but the bigger FAT needs some |
| 45 | more sectors, so the total number of clusters drop below the border |
| 46 | where MS-DOS expects a 12 bit FAT. So such filesystems would be FAT16, |
| 47 | but interpreted as FAT32 by DOS. The fix is to reduce filesystem size |
| 48 | a bit. |
| 49 | |
| 50 | - Roman <roman@hodek.net> |