Hi Pavel,

Pavel Shlyak 写道：
> I believe it is an important change as Raspberry PI (and I 
> suppose some other boards) cannot boot with fat16 boot 
> partitions. 

LGTM in principle.

The FS_BITS argument should be a regular number.  You can coerce 
it with number->string in the command line.

On the subject of being explicit is good: we should add "fat16" 
type and treat "vfat" as a softly deprecated alias.  But that can 
be done in a later patch.

Kind regards,

T G-R