Feature request: Directory to FAT12 Image emulation mode

[rgwan]

Some Chinese floppy emulators supports to emulate a whole directory (All files under this directory should not be exceeded 1.44MB) into a floppy disk image.

I think it's worth to implement this on flashfloppy (I have a original enhanced GOTEK 435 with OLED and encoder installed on YAMAHA EX5) because some platforms doesn't require an accurate image emulation and somehow it needs lots of disk image to fully load or export some data (Like sample data). It's so boring to make lots of image from these files, and it's much more easy to copy these files to some separated folder in the USB stick or copy these files directly from USB stick without unpack the floppy image.

I'm thinking that maybe the easy way to implement this feature is listed below:

1. When user choose a folder to emulate it as image(just for IBM-PC). Flashfloppy will list all files under this folder and create an FAT12 formatted 1.44MB swap image, and load it(only if the files and metadata size is below 1.44MB).
2. Read operation performs as normal.
3. Write operation will create a log file which maps swap image block number to USB LBA and FAT modification. When flashfloppy is in IDLE state, the changes will be flushed from logfile to actual file system on USB stick(modify file or create/delete files).

I will try to implement this feature on my spare time if anyone accepts this idea and willing to merge it into the upstream codebase.