How to get a device_t

[M. Warner Losh]

In message: <20030807120707.C7321 at freebsd1.cimlogic.com.au>
            John Birrell <jb at cimlogic.com.au> writes:
: On Wed, Aug 06, 2003 at 07:45:32PM -0600, M. Warner Losh wrote:
: > Well, I don't know.  The PC Cards that we have in the system are
: > mapped into the I/O and memory ranges traditionally reserved for the
: > ISA bus.  In ISA systems, this made sense because pccard was attached
: > to pcic was attached to isa.  However, now we have situations where
: > pccard is attached to cbb which is attached to pci.  There may be a
: > isab device with isa bus hanging off of it that makes the relationship
: > between the pccard devices cousins rather than nephews in the tree.
: > And there isn't any harm from that.  Wouldn't this be a similar
: > situation?
: 
: The flash I'm talking about is not pccard related. Sorry if I gave that
: impression.

No.  The pccard mention was to argue by analogy only :-)

: The SC520 has onboard support to control 3 flash chips.
: The board I have has 2 Mb NOR flash chip containing BIOS plus a DOS
: file system (at the moment) where I keep a copy of an etherboot
: executable. The board also has a 64Mb NAND flash chip which I've
: written a FreeBSD UFS image into. Our standard bootloader happily
: loads the kernel from that. Now I need to get a flash driver working
: for the root file system. I've got an existing read-only flash driver
: that I used to use on an Intel 386EX board, but that had the entire
: flash chip memory mapped. This new board maps the NAND flash in 4K
: pages.

That would be very very cool.  There's a number of new SBCs that I've
seen that have this sort of setup.  Timing Solutions might be very
interesting in something like this because we're currently buying CF
cards to do our OS.

: This URL lists the relevent docs:
: 
: <http://www.amd.com/us-en/ConnectivitySolutions/ProductInformation/0,,50_2330_8634_8635%5E8641,00.html>
: 
: The ones you want are the "ElanSC520 Users Manual" and "ElanSC520
: Register Set Manual"

Downloading now.

: If you have time, I'd be interested. This is a hot topic for me because
: it is exactly where I'm up to. I have everything else working on the
: board.

I'm thinking that it wouldn't take too long.  Lemme see what I can
throw together.  It would be a sketch only...

Warner