[U-Boot-Users] booting kernel image from jffs2 partition

[U-Boot-Users] booting kernel image from jffs2 partition

[Fabio Ubaldi]

Hi all,
I have a Spansion S29GL512N NOR flash. Specifically, I have two banks of 64 MB mapped in the following way: 

0xf4000000- 0xf7ffffff  First bank
0xfc000000-0xffffff     Second Bank (boot bank)

In the Linux kernel we have partitioned the flash in five parts:

0xf4000000 - 0xf43fffff Linux kernel image
0xf4400000 - 0xf4fffffff Rootfs Image
0xf5000000 - 0xf7ffffff Data1

0xfc000000 - 0xfff7ffff Data2
0xfff80000 - 0xffffffff U-boot image

We'd like to format linux kernel and rootfs image partitions (and the others) with jffs2, because the two images may be replaced with newer ones while Linux is running. 

A first question is: 
Is it possible to boot (bootm command) the images stored in partitions formatted using jffs2?
i.e. after the images are replaced and the machine is rebooted, can the u-boot be configured to read the new image from these jffs2 partitions?

If so, how is it possible to perform it?
Because from Internet and manual, I reckon out that u-boot works using binary or file-system images stored in raw way and I don't understand if the image can be read andloaded from a not-raw partitions.

Thanks in advance for the reply.
Fabio Ubaldi
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[U-Boot-Users] booting kernel image from jffs2 partition

[stefano babic]

Fabio Ubaldi wrote:
> We'd like to format linux kernel and rootfs image partitions (and the 
> others) with jffs2, because the two images may be replaced with newer 
> ones while Linux is running. 

It is not a problem to replace the linux image while it is running, 
because Linux runs from RAM. You can always replace the Linux image.

> A first question is:
> Is it possible to boot (bootm command) the images stored in partitions 
> formatted using jffs2?

U-boot can read JFFS2 partitions, but as I said, this should not be 
necessary if your goal is only to replace the kernel images. And u-boot 
does not need to understand the rootfs, too.

Regards,
stefano babic

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HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80  Email: office at denx.de
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[U-Boot-Users] booting kernel image from jffs2 partition

[Wolfgang Denk]

In message <46DED487.40607@denx.de> you wrote:
>
> > We'd like to format linux kernel and rootfs image partitions (and the 
> > others) with jffs2, because the two images may be replaced with newer 
> > ones while Linux is running. 
> 
> It is not a problem to replace the linux image while it is running, 
> because Linux runs from RAM. You can always replace the Linux image.

...unless you use XIP (eXecution In Place), which very few people do
as it usually brings only pain an no advantages.


Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The typical page layout program is nothing more  than  an  electronic
light table for cutting and pasting documents.

[U-Boot-Users] booting kernel image from jffs2 partition

[stefano babic]

Marco Stornelli wrote:
> Hi all,
> 
> I work with Fabio Ubaldi. The problem is this: the new linux kernel 
> image is send to system from a remote site and the system has to update 
> the image automatically. Our ideas was this: after the system had 
> mounted the jffs2 linux kernel partition, it copy the new image in 
> /mnt/kernel (jffs2 linux kernel partition) and after that the system is 
> rebooted. To perform this U-Boot must be able to boot a linux kernel 
> image from a jffs2 partition. I hope that the problem is now more clear.

I imagined this scenario, it is a very common user case.
However, it seems you add an additional layer you probably do not need.
The remote system sends the image and the target can store directly 
(yes, you can do it !) into /dev/mtd0 or whatever is your mtd device for 
the kernel, without caching it into a jffs2 partition. You really do not 
need to save it into the filesystem.

Regards,
stefano babic

-- 
=====================================================================
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80  Email: office at denx.de
=====================================================================

[U-Boot-Users] booting kernel image from jffs2 partition

[Marco Stornelli]

Stefano babic wrote:
 >Fabio Ubaldi wrote:
 >> We'd like to format linux kernel and rootfs image partitions (and the
 >> others) with jffs2, because the two images may be replaced with newer
 >> ones while Linux is running.

 >It is not a problem to replace the linux image while it is running,
 >because Linux runs from RAM. You can always replace the Linux image.

 >> A first question is:
 >> Is it possible to boot (bootm command) the images stored in partitions
 >> formatted using jffs2?

 >U-boot can read JFFS2 partitions, but as I said, this should not be
 >necessary if your goal is only to replace the kernel images. And u-boot
 >does not need to understand the rootfs, too.

 >Regards,
 >stefano babic

Hi all,

I work with Fabio Ubaldi. The problem is this: the new linux kernel 
image is send to system from a remote site and the system has to update 
the image automatically. Our ideas was this: after the system had 
mounted the jffs2 linux kernel partition, it copy the new image in 
/mnt/kernel (jffs2 linux kernel partition) and after that the system is 
rebooted. To perform this U-Boot must be able to boot a linux kernel 
image from a jffs2 partition. I hope that the problem is now more clear.

Thanks.
Marco Stornelli