From: Bruce Leonard <brucle@earthlink.net>
To: linux-kernel@vger.kernel.org
Subject: [PATCH 0/2][MTD] Support for > 2GiB MTD devices
Date: Thu, 21 Aug 2008 19:00:44 -0700 (GMT-07:00) [thread overview]
Message-ID: <10836950.1219370444356.JavaMail.root@elwamui-cypress.atl.sa.earthlink.net> (raw)
All,
Over the course of the last several months, I've been working on adding support to
the kernel for MTD devices that exceed 2GiB in size. In my particular case I
have a need for 8GiB of NAND flash that appears as a single device. I'm now
ready to submit my (first ever!) patch (please be kind :) ).
Design Details:
The problem - The size field of struct mtd_info is only 32-bits, which limits
the size of mtd devices to 2GiB (0x80000000).
The solution - The size of a device can be calculated buy multiplying the number
of erase blocks by the erase block size. I added a new field to struct
mtd_info to hold the number of erase blocks and an inline function to
determine the device size by returning mtd_info->size if it's non-zero
or returning (mtd_info->num_eraseblocks * mtd_info->erasesize).
A couple of comments. First and foremost, these patches don't completely change
the MTD layer. Due to my in-experience outside of what I was focused on
(NAND/UBI/UBIFS/MTDCHAR) I felt it was best if I restricted my changes to what I
knew. If the community feels I need to take these changes into the rest of the
MTD layer please advise. Secondly, there were changes that I needed to make in
mtd-utils, but I again only focused on the UBI sub-set. mtd-utils no longer builds
because of the changes (though the UBI tools still build). But I really do NOT
feel qualified to make changes to the rest of mtd-utils as they're tools I don't
use and don't understand and I don't want to accidentaly break something I don't
understand. The changes in mtd-utils are the same changes as in
.../include/linux/mtd/mtd.h and .../include/mtd/mtd-abi.h. If anyone has a
suggestion as to how I should handle mtd-utils I would appreciate it.
Thanks again to everyone who's answered my endless stupid questions.
Bruce
next reply other threads:[~2008-08-22 2:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-22 2:00 Bruce Leonard [this message]
2008-08-22 8:35 ` [PATCH 0/2][MTD] Support for > 2GiB MTD devices Frans Meulenbroeks
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