RO jffs2 implementation for bootloader

RO jffs2 implementation for bootloader

[Matthieu CASTET]

Hi,

I need to mount a jffs2 partition in a bootloader. I tried u-boot that support
jffs2, but it is very slow (2 minutes for mounting a 64MB partition).

Do you know if there are other (fast) implemenation of jffs2 suitable for a
bootloader ?


I want to avoid to use raw partition on NAND :
- because the bootloader need to access several files (kernel, boot data, rescue
images, some configuration).
- nand scrubbing (on read) is not possible to handle (jffs2 don't handle it
either if it is a read only partition)


Thanks

Re: RO jffs2 implementation for bootloader

[Artem Bityutskiy]

On Thu, 2007-05-03 at 08:40 +0000, Matthieu CASTET wrote:
> I need to mount a jffs2 partition in a bootloader. I tried u-boot that support
> jffs2, but it is very slow (2 minutes for mounting a 64MB partition).
> Do you know if there are other (fast) implemenation of jffs2 suitable for a
> bootloader ?

Not sure about any existing "fast" implementation, but mounting a JFFS2
partition is about scanning whole partition. You may optimize some
thing, but you have to scan anyway.

> I want to avoid to use raw partition on NAND :
> - because the bootloader need to access several files (kernel, boot data, rescue
> images, some configuration).
> - nand scrubbing (on read) is not possible to handle (jffs2 don't handle it
> either if it is a read only partition)

I would suggest to create a small JFFS2 partition with kernel so that it
is mounted quickly by the bootloader. Then you could mount it to /boot
of your "main" partition.

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)

Re: RO jffs2 implementation for bootloader

[Matthieu CASTET]

Hi Artem,

Artem Bityutskiy a écrit :
> On Thu, 2007-05-03 at 08:40 +0000, Matthieu CASTET wrote:
>> I need to mount a jffs2 partition in a bootloader. I tried u-boot that support
>> jffs2, but it is very slow (2 minutes for mounting a 64MB partition).
>> Do you know if there are other (fast) implemenation of jffs2 suitable for a
>> bootloader ?
> 
> Not sure about any existing "fast" implementation, but mounting a JFFS2
> partition is about scanning whole partition. You may optimize some
> thing, but you have to scan anyway.
> 
Well u-boot implementation is very slow. For 64MB partition : 2 minutes 
for u-boot and 11 s for linux (3s with summary).


>> I want to avoid to use raw partition on NAND :
>> - because the bootloader need to access several files (kernel, boot data, rescue
>> images, some configuration).
>> - nand scrubbing (on read) is not possible to handle (jffs2 don't handle it
>> either if it is a read only partition)
> 
> I would suggest to create a small JFFS2 partition with kernel so that it
> is mounted quickly by the bootloader. Then you could mount it to /boot
> of your "main" partition.
> 
Even with small partition, u-boot implementation is very slow, that's 
why I asks for other implementations.


While I am at it, is there some code of UBI (RO static partition) suited 
for integration in bootloaders ?


Thanks,

Matthieu

Re: RO jffs2 implementation for bootloader

[Artem Bityutskiy]

On Fri, 2007-05-04 at 11:55 +0200, Matthieu CASTET wrote:
> While I am at it, is there some code of UBI (RO static partition) suited 
> for integration in bootloaders ?

I am not aware of any public bootloader code, unfortunately.

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)

Re: RO jffs2 implementation for bootloader

[Stefan Roese]

Hi Matthieu,

On Friday 04 May 2007 11:55, Matthieu CASTET wrote:
> > On Thu, 2007-05-03 at 08:40 +0000, Matthieu CASTET wrote:
> >> I need to mount a jffs2 partition in a bootloader. I tried u-boot that
> >> support jffs2, but it is very slow (2 minutes for mounting a 64MB
> >> partition). Do you know if there are other (fast) implemenation of jffs2
> >> suitable for a bootloader ?
> >
> > Not sure about any existing "fast" implementation, but mounting a JFFS2
> > partition is about scanning whole partition. You may optimize some
> > thing, but you have to scan anyway.
>
> Well u-boot implementation is very slow. For 64MB partition : 2 minutes
> for u-boot

This really is slow. 64MB isn't that big and shouldn't take that long to 
mount.

> and 11 s for linux (3s with summary). 

So it can be done better.

Did you think about improving the performance in U-Boot? If so, please let's 
move this discussion to the u-boot-users mailing list.

Thanks.

BTW: What cpu at what speed are you using?

Best regards,
Stefan

Re: RO jffs2 implementation for bootloader

[Matthieu CASTET]

Hi Stefan,

Stefan Roese a écrit :
> Hi Matthieu,
> 
> On Friday 04 May 2007 11:55, Matthieu CASTET wrote:
>>> On Thu, 2007-05-03 at 08:40 +0000, Matthieu CASTET wrote:
>>>> I need to mount a jffs2 partition in a bootloader. I tried u-boot that
>>>> support jffs2, but it is very slow (2 minutes for mounting a 64MB
>>>> partition). Do you know if there are other (fast) implemenation of jffs2
>>>> suitable for a bootloader ?
>>> Not sure about any existing "fast" implementation, but mounting a JFFS2
>>> partition is about scanning whole partition. You may optimize some
>>> thing, but you have to scan anyway.
>> Well u-boot implementation is very slow. For 64MB partition : 2 minutes
>> for u-boot
> 
> This really is slow. 64MB isn't that big and shouldn't take that long to 
> mount.
> 
>> and 11 s for linux (3s with summary). 
> 
> So it can be done better.
> 
> Did you think about improving the performance in U-Boot? If so, please let's 
> move this discussion to the u-boot-users mailing list.

Somebody already try something for u-boot jffs2 [1], but is doesn't seem 
to work (don't compile).
He didn't receive any report, so u-boot jffs2 code seems unmaintained.

> 
> Thanks.
> 
> BTW: What cpu at what speed are you using?
an arm9 @240 Mhz.

Matthieu


[1] http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/25780/focus=25808

Re: RO jffs2 implementation for bootloader

[Matthieu CASTET]

Hi Stefan,

Stefan Roese a écrit :
> Hi Matthieu,
> 
> On Friday 04 May 2007 11:55, Matthieu CASTET wrote:
>>> On Thu, 2007-05-03 at 08:40 +0000, Matthieu CASTET wrote:
>>>> I need to mount a jffs2 partition in a bootloader. I tried u-boot that
>>>> support jffs2, but it is very slow (2 minutes for mounting a 64MB
>>>> partition). Do you know if there are other (fast) implemenation of jffs2
>>>> suitable for a bootloader ?
>>> Not sure about any existing "fast" implementation, but mounting a JFFS2
>>> partition is about scanning whole partition. You may optimize some
>>> thing, but you have to scan anyway.
>> Well u-boot implementation is very slow. For 64MB partition : 2 minutes
>> for u-boot
> 
> This really is slow. 64MB isn't that big and shouldn't take that long to 
> mount.
> 
>> and 11 s for linux (3s with summary). 
> 
> So it can be done better.
> 
> Did you think about improving the performance in U-Boot? If so, please let's 
> move this discussion to the u-boot-users mailing list.

Somebody already try something for u-boot jffs2 [1], but is doesn't seem
to work (don't compile).
He didn't receive any report, so u-boot jffs2 code seems unmaintained.

> 
> Thanks.
> 
> BTW: What cpu at what speed are you using?
an arm9 @240 Mhz.

Matthieu


[1] http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/25780/focus=25808

Re: RO jffs2 implementation for bootloader

[Matthieu CASTET]

Hi Stefan,

Stefan Roese a écrit :
> Hi Matthieu,
> 
> On Friday 04 May 2007 11:55, Matthieu CASTET wrote:
>>> On Thu, 2007-05-03 at 08:40 +0000, Matthieu CASTET wrote:
>>>> I need to mount a jffs2 partition in a bootloader. I tried u-boot that
>>>> support jffs2, but it is very slow (2 minutes for mounting a 64MB
>>>> partition). Do you know if there are other (fast) implemenation of jffs2
>>>> suitable for a bootloader ?
>>> Not sure about any existing "fast" implementation, but mounting a JFFS2
>>> partition is about scanning whole partition. You may optimize some
>>> thing, but you have to scan anyway.
>> Well u-boot implementation is very slow. For 64MB partition : 2 minutes
>> for u-boot
> 
> This really is slow. 64MB isn't that big and shouldn't take that long to 
> mount.
> 
>> and 11 s for linux (3s with summary). 
> 
> So it can be done better.
> 
> Did you think about improving the performance in U-Boot? If so, please let's 
> move this discussion to the u-boot-users mailing list.

Somebody already try something for u-boot jffs2 [1], but is doesn't seem
to work (don't compile).
He didn't receive any report, so u-boot jffs2 code seems unmaintained.

> 
> Thanks.
> 
> BTW: What cpu at what speed are you using?
an arm9 @240 Mhz.

Matthieu


[1] http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/25780/focus=25808



-- 
Matthieu Castet
Ingénieur Développement Logiciel
Parrot SA
174 Quai de Jemmapes
75010 Paris, France

Tél: +33 (0) 1 48 03 74 78
Fax: +33 (0) 1 48 03 06 66
Email: matthieu.castet@parrot.fr
http://www.parrot.biz

Re: [U-Boot-Users] RO jffs2 implementation for bootloader

[Stefan Roese]

On Friday 04 May 2007 14:10, Matthieu CASTET wrote:
> > Did you think about improving the performance in U-Boot? If so, please
> > let's move this discussion to the u-boot-users mailing list.
>
> Somebody already try something for u-boot jffs2 [1], but is doesn't seem
> to work (don't compile).
> He didn't receive any report, so u-boot jffs2 code seems unmaintained.

I am willing to work with you on this issue. And will help to get it included.

Could you perhaps work on the patch (looks promising) mentioned below to get 
it working in the current U-Boot version? This would help. I'll give it a try 
on some of my systems too then.

> http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/25780/focus=25808

Best regards,
Stefan

Re: RO jffs2 implementation for bootloader

[Joakim Tjernlund]

On Fri, 2007-05-04 at 13:53 +0200, Stefan Roese wrote:
> Hi Matthieu,
> 
> On Friday 04 May 2007 11:55, Matthieu CASTET wrote:
> > > On Thu, 2007-05-03 at 08:40 +0000, Matthieu CASTET wrote:
> > >> I need to mount a jffs2 partition in a bootloader. I tried u-boot that
> > >> support jffs2, but it is very slow (2 minutes for mounting a 64MB
> > >> partition). Do you know if there are other (fast) implemenation of jffs2
> > >> suitable for a bootloader ?
> > >
> > > Not sure about any existing "fast" implementation, but mounting a JFFS2
> > > partition is about scanning whole partition. You may optimize some
> > > thing, but you have to scan anyway.
> >
> > Well u-boot implementation is very slow. For 64MB partition : 2 minutes
> > for u-boot
> 
> This really is slow. 64MB isn't that big and shouldn't take that long to 
> mount.
> 
> > and 11 s for linux (3s with summary). 
> 
> So it can be done better.
> 
> Did you think about improving the performance in U-Boot? If so, please let's 
> move this discussion to the u-boot-users mailing list.

Someone sent a patch a while ago to this list(I think) which had
significant improvemets to JFFS2 load time.

 jocke

Re: RO jffs2 implementation for bootloader

[David Woodhouse]

On Thu, 2007-05-03 at 08:40 +0000, Matthieu CASTET wrote:
> I need to mount a jffs2 partition in a bootloader. I tried u-boot that support
> jffs2, but it is very slow (2 minutes for mounting a 64MB partition).
> 
> Do you know if there are other (fast) implemenation of jffs2 suitable for a
> bootloader ?

The version of OpenFirmware which we use on OLPC has JFFS2 support. And
eCos also has JFFS2 support, which means that RedBoot does too.

If you build using -ffunction-sections --gc-sections (as eCos/RedBoot
does), and if you never call the write functions, a huge amount of JFFS2
just drops out of the build.

-- 
dwmw2