Create FAT partition/filesystem on the internal microSD flash of the Dreamplug

[Mattia Rossi]

Hi all again,

I've now been on to this for quite a while, but just can't get it to work.
I've mistakenly blown away the partitioning scheme that the dreamplug 
came with originally, therefore also the FAT boot partition.

I've tried to recreate it using gpart and newfs_msdos, but can't create 
any new FAT partition that mount_msdosfs would mount.

See:

dreamplug# gpart create -s mbr da0
da0 created
dreamplug# gpart add -t fat32  -i 1 -s 32M da0
da0s1 added
dreamplug# newfs_msdos da0s1
/dev/da0s1: 65416 sectors in 8177 FAT16 clusters (4096 bytes/cluster)
BytesPerSec=512 SecPerClust=8 ResSectors=1 FATs=2 RootDirEnts=512 
Sectors=65520 Media=0xf0 FATsecs=32 SecPerTrack=63 Heads=255 HiddenSecs=0
dreamplug# mount_msdosfs /dev/da0s1 /mnt/usb
mount_msdosfs: /dev/da0s1: Invalid argument

I've tried to change the partition type to 6 and 4 and to freebsd (165), 
but didn't help.
I also tried to set the start of the partition (-b) to 64, 128 and 192 
but nothing there either.

Trying to tune newfs_msdos to use FAT 12 or FAT 32 and  different 
bytes/sec or a different mediatype (0xf8) and a variety of tweaks did 
not help either.

It seems that I can't create a mountable FAT partition.

I believe the problem is that gpart create -s mbr starts the 
partitioning scheme at an offset of 63 sectors, while the one on the 
external SD card I have (pre-partitioned not using FreeBSD) has an 
offset of 32 sectors.

I couldn't find any documentation that tells me how to tell gpart create 
to use a different offset.

Any hints?

Mat