Dear All,
We are developing a embedded device based on linux. Through the
development phase we used NFS. But now we want to move some
filesystem
which can be created in FLASH/RAM.
I have few doubts about the file system in embedded devices.
1) What is the file system which is used normally in all embedded
devices? (JFFS/CRAMFS/RAM DISK)
2) We tried using RAM disk as the file system. But since our
application is huge it is not able to fit into 8 MB RAM disk
created. When we tried to increase the size of the RAM disk, the
kernel crashes above 9 MB. We have 32 MB in our target board.
3) I dont know whether we can use cramfs.
Can anybody suggest me some ideas so that i can solve these
issues?
Thanks and Regards,
Nanda
On Sat, 2003-02-08 at 14:20, Nandakumar NarayanaSwamy wrote:
> Dear All,
>
> We are developing a embedded device based on linux. Through the
> development phase we used NFS. But now we want to move some
> filesystem which can be created in FLASH/RAM.
Which? Flash or RAM?
> Can anybody suggest me some ideas so that i can solve these
> issues?
You need to give at least _some_ indication of your requirements --
what's on your file system, what is the expected pattern of access to
it, do you require write access all the time or only occasional updates
of the whole system, etc. ?
--
dwmw2
Dear David,
Thanks for your inputs.
Actually i have 8 MB flash and 32 MB RAM in my target board.
I need to create a read-only file system either in flash or RAM
which should be able to accomodate our application which is about
8 MB (stripped one).
Thanks again for your response.
with best regards,
Purush
On Sun, 09 Feb 2003 David Woodhouse wrote :
>On Sat, 2003-02-08 at 14:20, Nandakumar NarayanaSwamy wrote:
> > Dear All,
> >
> > We are developing a embedded device based on linux. Through
>the
> > development phase we used NFS. But now we want to move some
> > filesystem which can be created in FLASH/RAM.
>
>Which? Flash or RAM?
>
> > Can anybody suggest me some ideas so that i can solve these
> > issues?
>
>You need to give at least _some_ indication of your requirements
>--
>what's on your file system, what is the expected pattern of
>access to
>it, do you require write access all the time or only occasional
>updates
>of the whole system, etc. ?
>
>
>--
>dwmw2
>
I'm confused. I looked below the text of my mail which you had quoted,
but couldn't see that you'd actually added anything new in response. Did
you hit 'Send' too soon?
By the way, your mail directly to me ended up in the spam bin because it
had no References: or In-Reply-To: headers to correctly identify the
mail to which you were replying.
--
dwmw2
We use JFFS2 for configuration parameters etc, cramfs for
binaries etc and tmpfs for temporary data (our embedded
devices typically have 4 MB flash and 16 MB RAM).
/Mikael
-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Nandakumar
NarayanaSwamy
Sent: Saturday, February 08, 2003 3:20 PM
To: [email protected]
Subject: File systems in embedded devices
Dear All,
We are developing a embedded device based on linux. Through the
development phase we used NFS. But now we want to move some
filesystem
which can be created in FLASH/RAM.
I have few doubts about the file system in embedded devices.
1) What is the file system which is used normally in all embedded
devices? (JFFS/CRAMFS/RAM DISK)
2) We tried using RAM disk as the file system. But since our
application is huge it is not able to fit into 8 MB RAM disk
created. When we tried to increase the size of the RAM disk, the
kernel crashes above 9 MB. We have 32 MB in our target board.
3) I dont know whether we can use cramfs.
Can anybody suggest me some ideas so that i can solve these
issues?
Thanks and Regards,
Nanda
Dear David,
Thanks for your response.
I sent it correctly after typing the full mail. I think this is
some problem in rediff mails itself.
Anyway these are the my requirements:
1) My application is coming around 8 MB. So need a file system
about 12 MB to which i should be able to mount the root of the
Linux kernel.
2) I need read-only file system.
3) Is it possible to create multiple ram disks of multiple file
systems like CRAMFS, RAMDISK for a single kernel?
Thanks in advance,
Nanda
On Sun, 09 Feb 2003 David Woodhouse wrote :
>On Sat, 2003-02-08 at 14:20, Nandakumar NarayanaSwamy wrote:
> > Dear All,
> >
> > We are developing a embedded device based on linux. Through
>the
> > development phase we used NFS. But now we want to move some
> > filesystem which can be created in FLASH/RAM.
>
>Which? Flash or RAM?
>
> > Can anybody suggest me some ideas so that i can solve these
> > issues?
>
>You need to give at least _some_ indication of your requirements
>--
>what's on your file system, what is the expected pattern of
>access to
>it, do you require write access all the time or only occasional
>updates
>of the whole system, etc. ?
>
>
>--
>dwmw2
>
Dear David,
Thanks for your response.
I sent it correctly after typing the full mail. I think this is
some problem in rediff mails itself.
Anyway these are the my requirements:
1) My application is coming around 8 MB. So need a file system
about 12 MB to which i should be able to mount the root of the
Linux kernel.
2) I need read-only file system.
3) Is it possible to create multiple ram disks of multiple file
systems like CRAMFS, RAMDISK for a single kernel?
Thanks in advance,
Nanda
On Sun, 09 Feb 2003 David Woodhouse wrote :
>On Sat, 2003-02-08 at 14:20, Nandakumar NarayanaSwamy wrote:
> > Dear All,
> >
> > We are developing a embedded device based on linux. Through
>the
> > development phase we used NFS. But now we want to move some
> > filesystem which can be created in FLASH/RAM.
>
>Which? Flash or RAM?
>
> > Can anybody suggest me some ideas so that i can solve these
> > issues?
>
>You need to give at least _some_ indication of your requirements
>--
>what's on your file system, what is the expected pattern of
>access to
>it, do you require write access all the time or only occasional
>updates
>of the whole system, etc. ?
>
>
>--
>dwmw2
>
On Mon, 2003-02-10 at 05:48, Nandakumar NarayanaSwamy wrote:
> I sent it correctly after typing the full mail. I think this is
> some problem in rediff mails itself.
No, I was being sarcastic. There's no text below your quotation in this
mail from you either. It's all at the top. Please don't do that.
You are still violating
http://www.infradead.org/~dwmw2/email.html#references
http://www.infradead.org/~dwmw2/email.html#top-posting
http://www.infradead.org/~dwmw2/email.html#quote-selectively
and probably also to a certain extent
http://www.infradead.org/~dwmw2/email.html#include
> Anyway these are the my requirements:
>
> 1) My application is coming around 8 MB. So need a file system
> about 12 MB to which i should be able to mount the root of the
> Linux kernel.
>
> 2) I need read-only file system.
If you really only need it to be read-only, and assuming NOR flash, then
cramfs on a flash device sounds like a sane option. If you have NAND
flash then it's slightly more complicated -- you probably need a real
writable file system which deals with NAND but you could use it in
read-only mode.
> 3) Is it possible to create multiple ram disks of multiple file
> systems like CRAMFS, RAMDISK for a single kernel?
Why? Where would these ramdisks be loaded from in the first place?
Wouldn't you do better to use them directly from there rather than
copying them into precious RAM?
--
dwmw2
>No, I was being sarcastic. There's no text below your quotation
>in this
>mail from you either. It's all at the top. Please don't do
>that.
>
Thank you very much David.
I was making mistakes all these days. Thank you very much
really.
>If you really only need it to be read-only, and assuming NOR
>flash, then
>cramfs on a flash device sounds like a sane option. If you have
>NAND
>flash then it's slightly more complicated -- you probably need a
>real
>writable file system which deals with NAND but you could use it
>in
>read-only mode.
Thank you very much. I will try again with CRAMFS.
Nanda