Formatting JFFS2 Flash

Formatting JFFS2 Flash

[Billalabeitia, Jose Carlos (IndSys, GEPM)]

Hi:

	I have a PPC 860T custom board with kernel
2.4.4-2001-11-11-denx and rtai-24.1.4-2-denx. I have
a JFFS2 filesystem on 14MB Flash. I make an initial
filesystem with the "mkfs.jffs2" utility, and the first time
I copy a 1MB file into it, it takes about 2 minutes, and
then on it takes 10 seconds to copy into it the same file.
I suppose that the first time, jffs2 is doing something like
"formatting" the flash.
Does anybody out there know how to do this "formatting"
in a smarter way?

				Thank you
					Billa

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RE: Formatting JFFS2 Flash

[Navin Boppuri]

You should try the linux-mtd mailing lists.

http://lists.infradead.org/mailman/listinfo/linux-mtd/

Navin.

-----Original Message-----
From: Billalabeitia, Jose Carlos (IndSys, GEPM)
[mailto:jc.billalabeitia@indsys.ge.com]
Sent: Wednesday, March 13, 2002 9:50 AM
To: linuxppc-embedded@lists.linuxppc.org
Subject: Formatting JFFS2 Flash



Hi:

	I have a PPC 860T custom board with kernel
2.4.4-2001-11-11-denx and rtai-24.1.4-2-denx. I have
a JFFS2 filesystem on 14MB Flash. I make an initial
filesystem with the "mkfs.jffs2" utility, and the first time
I copy a 1MB file into it, it takes about 2 minutes, and
then on it takes 10 seconds to copy into it the same file.
I suppose that the first time, jffs2 is doing something like
"formatting" the flash.
Does anybody out there know how to do this "formatting"
in a smarter way?

				Thank you
					Billa


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: Formatting JFFS2 Flash

[Alex Zeffertt]

Question:

Did you initialise the FS with

cat jffs2.image > /dev/mtd0

before you tried to mount /mtdblock0 ?

If you did not, then kernel threads will indeed start formatting the FS after you mount it.

2nd question:

Did you use an empty directory with mkfs.jffs2 to make your jffs2.image?  This doesn't work - you
end up with a 0 length jffs2.image!  If this was the case then even if you did initialise the FS
with "cat jffs2.image > /dev/mtd0" you will still find the kernel threads format the FS after you
mount it.

I think this is a bug - the workaround is to use a non-empty folder to make your jffs2.image from.

Alex

Billalabeitia, Jose Carlos (IndSys, GEPM) wrote:

> Hi:
>
> 	I have a PPC 860T custom board with kernel
> 2.4.4-2001-11-11-denx and rtai-24.1.4-2-denx. I have
> a JFFS2 filesystem on 14MB Flash. I make an initial
> filesystem with the "mkfs.jffs2" utility, and the first time
> I copy a 1MB file into it, it takes about 2 minutes, and
> then on it takes 10 seconds to copy into it the same file.
> I suppose that the first time, jffs2 is doing something like
> "formatting" the flash.
> Does anybody out there know how to do this "formatting"
> in a smarter way?
>
> 				Thank you
> 					Billa
>
>
>


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Re: Formatting JFFS2 Flash

[Billalabeitia, Jose Carlos (IndSys, GEPM)]

Hi Alex:

First of all, thank you for your answer. You wrote:

> Did you initialise the FS with
> cat jffs2.image > /dev/mtd0
> before you tried to mount /mtdblock0 ?

	I tried it in two ways, and in both of them
I got the same result:

	1.- By flashing "jffs2.image" directly to
	    its location address.

	2.- cp jffs2.image /dev/mtd0

and then mounting it into the system.

> Did you use an empty directory with mkfs.jffs2
> to make your jffs2.image?  This doesn't work
> - you end up with a 0 length jffs2.image!

	No, the directory is not empty.

					Thank you
						Billa


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Re: Formatting JFFS2 Flash

[Billalabeitia, Jose Carlos (IndSys, GEPM)]

Hi Alex:

First of all, thank you for your answer. You wrote:

> Did you initialise the FS with
> cat jffs2.image > /dev/mtd0
> before you tried to mount /mtdblock0 ?

	I tried it in two ways, and in both of them
I got the same result:

	1.- By flashing "jffs2.image" directly to
	    its location address.

	2.- cp jffs2.image /dev/mtd0

and then mounting it into the system.

> Did you use an empty directory with mkfs.jffs2
> to make your jffs2.image?  This doesn't work
> - you end up with a 0 length jffs2.image!

	No, the directory is not empty.

					Thank you
						Billa


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Re: Formatting JFFS2 Flash

[Alex Zeffertt]

>
> 	2.- cp jffs2.image /dev/mtd0
>
> and then mounting it into the system.
>

This looks wrong.  You should use

cat jffs2.image > /dev/mtd0

Alex


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Re: Formatting JFFS2 Flash

[Wolfgang Denk]

In message <3C908A1A.3070102@cambridgebroadband.com> you wrote:
>
> > 	2.- cp jffs2.image /dev/mtd0
>
> This looks wrong.  You should use
>
> cat jffs2.image > /dev/mtd0

Ummm... what's the difference?

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
Don't panic.

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RE: Formatting JFFS2 Flash

[Jim Lewis]

Did you remember to erase the flash first with:
	erase /dev/mtd0
Then "xxd /dev/mtd0" should show all FF's. You can't write
successfully unless it is erased first. Forgive me if I am stating the
obvious :)

-Jim Lewis

> -----Original Message-----
> From: owner-linuxppc-embedded@lists.linuxppc.org
> [mailto:owner-linuxppc-embedded@lists.linuxppc.org]On Behalf Of
> Billalabeitia, Jose Carlos (IndSys, GEPM)
> Sent: Thursday, March 14, 2002 2:34 AM
> To: linuxppc-embedded@lists.linuxppc.org
> Subject: Re: Formatting JFFS2 Flash
>
>
>
> Hi Alex:
>
> First of all, thank you for your answer. You wrote:
>
> > Did you initialise the FS with
> > cat jffs2.image > /dev/mtd0
> > before you tried to mount /mtdblock0 ?
>
> 	I tried it in two ways, and in both of them
> I got the same result:
>
> 	1.- By flashing "jffs2.image" directly to
> 	    its location address.
>
> 	2.- cp jffs2.image /dev/mtd0
>
> and then mounting it into the system.
>
> > Did you use an empty directory with mkfs.jffs2
> > to make your jffs2.image?  This doesn't work
> > - you end up with a 0 length jffs2.image!
>
> 	No, the directory is not empty.
>
> 					Thank you
> 						Billa
>
>


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RE: Formatting JFFS2 Flash

[Billalabeitia, Jose Carlos (IndSys, GEPM)]

Jim Lewis wrote:

> Did you remember to erase the flash first with:
>	erase /dev/mtd0

	Yes, I erased it in two ways:
		- by using the "erase" command
		- from the ppcboot.

					Billa


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