PicoBSD diskless embedded 'where to start'

[Cybertime Hostmaster]

> I'm trying to put together a diskless embedded system based on
> the PicoBSD scripts supplied with FreeBSD 4.8R.


Just as a point of interest, any special reason why PicoBSD?

> 1) I need to build a PicoBSD system that will boot from a flash device
> (SanDisk at the moment, may need support for M-Systems DiskOnChip later)

The smallest M-Systems seems to have is 16 MB.

http://www.m-sys.com/Content/Products/DiskOnChip.asp

> 2) The system will run out of RAM, there will be no HDD available.
> 3) The flash will have two partitions, the boot image and compressed
> memory-resident runtime will be stored in the lower, read-only one.
> The upper one will be for precious data required across boots.

It sounds like you will have more room than a floppy.

Pico makes some hard choices based off of fitting into a floppy.  If you
are going to allow a bit more space, you might want to look at a different
BSD.  But if you have something already developed for Pico, it may be
worth it to stay with them.

m0n0BSD is another good choice from what I have seen.

http://m0n0.ch/bsd/

That one will fit on an 8 MB CF and have plenty of room to spare.  So the
16 MB DiskOnChip would be a huge volume of space.  Heck, you could have 2
copies of the whole OS to go from one to another while upgrading.

--Eric