Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 28 Nov 1998 00:28:52 -0800
From:      Mike Smith <mike@smith.net.au>
To:        Poul-Henning Kamp <phk@critter.freebsd.dk>
Cc:        Mike Smith <mike@smith.net.au>, Warner Losh <imp@village.org>, mobile@FreeBSD.ORG
Subject:   Re: Flash card support 
Message-ID:  <199811280828.AAA00741@dingo.cdrom.com>
In-Reply-To: Your message of "Sat, 28 Nov 1998 09:16:00 %2B0100." <4747.912240960@critter.freebsd.dk> 

next in thread | previous in thread | raw e-mail | index | archive | help
> In message <199811280052.QAA01774@dingo.cdrom.com>, Mike Smith writes:
> >> 
> >> >Any ideas if there is a free Flash File System implementation around?
> >> 
> >> Don't kill me for this, but LFS would be close to ideal...
> >
> >Are you sure?  I don't think it bothers with anything like block 
> >forwarding or write levelling...
> 
> Both would be trivial to add.
> 
> I don't think M-systems considers their FTL any less a company secret
> than before.  I have the source here because of the DOC2000 driver

It's documented in the PCMCIA 6.1 spec, at least to the extent of the 
format on the card, so it's probably possible to implement at least the 
basic functionality from that.

> (which I have promised to do a (binary) release of this weekend if at 
> all possible.)
> 
> Designing and implementing a FTL isn't hard, but it would be much smarter
> to teack LFS the few remaining ropes, since a flash-aware filesystem can
> achive much higher performance than a FTL trying to look like a disk.

The major advantage with flash cards is portability, not performance.  
LFS is so badly broken (it seems) that making it play nicely with flash 
memory would be a lot less work than simply making it work at all.

-- 
\\  Sometimes you're ahead,       \\  Mike Smith
\\  sometimes you're behind.      \\  mike@smith.net.au
\\  The race is long, and in the  \\  msmith@freebsd.org
\\  end it's only with yourself.  \\  msmith@cdrom.com



To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-mobile" in the body of the message



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199811280828.AAA00741>