All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dzuy Nguyen <dzuy@infinity-studios.com>
To: "linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>
Subject: Re: jffs2: Too few erase blocks (1)
Date: Mon, 09 Feb 2009 09:39:52 -0600	[thread overview]
Message-ID: <49904E48.7000805@infinity-studios.com> (raw)
In-Reply-To: <Pine.LNX.4.64.0902090947080.19761@lnxricardw.se.axis.com>

Thanks, Ricard.  I didn't realize that jffs2 is not suitable for a small
partition.  Yes,
64K is all I can afford.  I suppose I can dd the file, but doesn't that
provide no wear
leveling feature that jffs2 does?

Ricard Wanderlof wrote:
> On Mon, 9 Feb 2009, Dzuy Nguyen wrote:
>
>   
>> I've allocated a small (64K) "user_config" partition in my flash for
>> persistence storage:
>>
>> mtd0: 00020000 00010000 "u-boot"
>> mtd1: 00010000 00010000 "Config"
>> mtd2: 00100000 00010000 "vmlinux"
>> mtd3: 002a0000 00010000 "rootfs"
>> mtd4: 00010000 00010000 "user_config"
>> mtd5: 00020000 00010000 "ART"
>>
>> When I tried to mount -t jffs2 /dev/mtdblock4, I get
>>
>> jffs2: Too few erase blocks (1)
>>
>> I understand that my erasesize is 64K, which gives me only 1 block,
>> and jffs2 needs more than 1 block, but the kernel defaults the erasesize
>> to 64K.
>>     
>
> The kernel does that probably because that is the size of the blocks on 
> your flash chip. It is not so much a default as detection of the 
> properties of the chip.
>
>   
>> If I made a jffs2 file with eraseblock=8, would this work or would I have
>> to set it at the kernel?
>>     
>
> You need to allocate more space if you want to use jffs2 quite simply. The 
> exact number is not exact; 8 should be ok, meaning you need to partition 
> your flash so you have 64K * 8 = 512K in your user_config partition.
>
> If you can't afford that much space, you could consider writing your user 
> configurations to a file and just dumping the file with dd into your flash 
> partition. Not at all as flexible, but doable in a pinch.
>
> /Ricard
> --
> Ricard Wolf Wanderlöf                           ricardw(at)axis.com
> Axis Communications AB, Lund, Sweden            www.axis.com
> Phone +46 46 272 2016                           Fax +46 46 13 61 30
>
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/
>   

  reply	other threads:[~2009-02-09 15:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-02-09  5:52 jffs2: Too few erase blocks (1) Dzuy Nguyen
2009-02-09  8:50 ` Ricard Wanderlof
2009-02-09 15:39   ` Dzuy Nguyen [this message]
2009-02-09 16:32     ` Ricard Wanderlof
2009-02-10  4:16       ` Dzuy Nguyen
2009-02-10 12:41         ` Jamie Lokier

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=49904E48.7000805@infinity-studios.com \
    --to=dzuy@infinity-studios.com \
    --cc=linux-mtd@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.