Yaffs2 on None-ECC MTD

Yaffs2 on None-ECC MTD

[Woody Wu]

Hi,

Does Yaffs2 file system has its own capabilities to do ECC? My NAND
driver for some reason cannot enable ECC yet.  Also I want to ask the
same question to Jffs2.

Thanks in advance.

-- 
I can't go back to yesterday - because I was a different person then

Yaffs2 on None-ECC MTD

[richard -rw- weinberger]

On Sat, Aug 17, 2013 at 10:28 AM, Woody Wu <narkewoody@gmail.com> wrote:
> Hi,
>
> Does Yaffs2 file system has its own capabilities to do ECC? My NAND
> driver for some reason cannot enable ECC yet.  Also I want to ask the
> same question to Jffs2.

The Linux MTD subsystem is able to do software ECC.

-- 
Thanks,
//richard

Yaffs2 on None-ECC MTD

[Woody Wu]

On Sat, Aug 17, 2013 at 12:58:41PM +0200, richard -rw- weinberger wrote:
> On Sat, Aug 17, 2013 at 10:28 AM, Woody Wu <narkewoody@gmail.com> wrote:
> > Hi,
> >
> > Does Yaffs2 file system has its own capabilities to do ECC? My NAND
> > driver for some reason cannot enable ECC yet.  Also I want to ask the
> > same question to Jffs2.
> 
> The Linux MTD subsystem is able to do software ECC.
> 
By far, I cannot enable any kind of ECC from MTD yet, since my u-boot
has some problem cannot do correct ECC and my root file system image is
flashed by u-boot. If I enabled ECC from MTD, my root file system cannot
mount.

Do you know whethe Yaffs2/Jffs2 has their own build-in ECC function?
Googled this but not get clear answer.

-- 
I can't go back to yesterday - because I was a different person then

Yaffs2 on None-ECC MTD

[richard -rw- weinberger]

On Sat, Aug 17, 2013 at 2:37 PM, Woody Wu <narkewoody@gmail.com> wrote:
> On Sat, Aug 17, 2013 at 12:58:41PM +0200, richard -rw- weinberger wrote:
>> On Sat, Aug 17, 2013 at 10:28 AM, Woody Wu <narkewoody@gmail.com> wrote:
>> > Hi,
>> >
>> > Does Yaffs2 file system has its own capabilities to do ECC? My NAND
>> > driver for some reason cannot enable ECC yet.  Also I want to ask the
>> > same question to Jffs2.
>>
>> The Linux MTD subsystem is able to do software ECC.
>>
> By far, I cannot enable any kind of ECC from MTD yet, since my u-boot
> has some problem cannot do correct ECC and my root file system image is
> flashed by u-boot. If I enabled ECC from MTD, my root file system cannot
> mount.

Then fix your uboot. Or at least hire someone to do so.
Otherwise you *will* encounter massive problems.

> Do you know whethe Yaffs2/Jffs2 has their own build-in ECC function?
> Googled this but not get clear answer.

IIRC yaffs2 has it's own ECC stuff. It writes into the spare area which is
a no-go and one of the reasons why it's not mainline.

-- 
Thanks,
//richard

Yaffs2 on None-ECC MTD

[Woody Wu]

On Sat, Aug 17, 2013 at 05:43:56PM +0200, richard -rw- weinberger wrote:
> On Sat, Aug 17, 2013 at 2:37 PM, Woody Wu <narkewoody@gmail.com> wrote:
> > On Sat, Aug 17, 2013 at 12:58:41PM +0200, richard -rw- weinberger wrote:
> >> On Sat, Aug 17, 2013 at 10:28 AM, Woody Wu <narkewoody@gmail.com> wrote:
> >> > Hi,
> >> >
> >> > Does Yaffs2 file system has its own capabilities to do ECC? My NAND
> >> > driver for some reason cannot enable ECC yet.  Also I want to ask the
> >> > same question to Jffs2.
> >>
> >> The Linux MTD subsystem is able to do software ECC.
> >>
> > By far, I cannot enable any kind of ECC from MTD yet, since my u-boot
> > has some problem cannot do correct ECC and my root file system image is
> > flashed by u-boot. If I enabled ECC from MTD, my root file system cannot
> > mount.
> 
> Then fix your uboot. Or at least hire someone to do so.
> Otherwise you *will* encounter massive problems.
> 
> > Do you know whethe Yaffs2/Jffs2 has their own build-in ECC function?
> > Googled this but not get clear answer.
> 
> IIRC yaffs2 has it's own ECC stuff. It writes into the spare area which is
> a no-go and one of the reasons why it's not mainline.
> 

Hi, Richard,

Many thanks for your information and suggestions. I will be doing some
homework and tryings before come back.

-- 
I can't go back to yesterday - because I was a different person then

Yaffs2 on None-ECC MTD

[Woody Wu]

On Sat, Aug 17, 2013 at 05:43:56PM +0200, richard -rw- weinberger wrote:
> On Sat, Aug 17, 2013 at 2:37 PM, Woody Wu <narkewoody@gmail.com> wrote:
> > On Sat, Aug 17, 2013 at 12:58:41PM +0200, richard -rw- weinberger wrote:
> >> On Sat, Aug 17, 2013 at 10:28 AM, Woody Wu <narkewoody@gmail.com> wrote:
> >> > Hi,
> >> >
> >> > Does Yaffs2 file system has its own capabilities to do ECC? My NAND
> >> > driver for some reason cannot enable ECC yet.  Also I want to ask the
> >> > same question to Jffs2.
> >>
> >> The Linux MTD subsystem is able to do software ECC.
> >>
> > By far, I cannot enable any kind of ECC from MTD yet, since my u-boot
> > has some problem cannot do correct ECC and my root file system image is
> > flashed by u-boot. If I enabled ECC from MTD, my root file system cannot
> > mount.
> 
> Then fix your uboot. Or at least hire someone to do so.
> Otherwise you *will* encounter massive problems.
> 
> > Do you know whethe Yaffs2/Jffs2 has their own build-in ECC function?
> > Googled this but not get clear answer.
> 
> IIRC yaffs2 has it's own ECC stuff. It writes into the spare area which is
> a no-go and one of the reasons why it's not mainline.
> 
> -- 
> Thanks,
> //richard

Just report back the list:  I've managed to mount root from NFS, by
which I can use pure Linux way to prepare my root filesystems to yaffs2
and enable HW ECC in MTD layer only. Then I can ignore the mismatch
between u-boot and kernel in the ways they handing NAND OOB area.

Thanks.

-- 
I can't go back to yesterday - because I was a different person then

Yaffs2 on None-ECC MTD

[Mandeep Sandhu]

> Just report back the list:  I've managed to mount root from NFS, by
> which I can use pure Linux way to prepare my root filesystems to yaffs2
> and enable HW ECC in MTD layer only. Then I can ignore the mismatch
> between u-boot and kernel in the ways they handing NAND OOB area.
>

But your boot-loader still needs to read the NAND flash for loading the
kernel image. Won't it be a problem if uboot doesn't understand ECC? What
if some blocks have gone bad, uboot might load a corrupted kernel image.

CMIIW.

-mandeep


> Thanks.
>
> --
> I can't go back to yesterday - because I was a different person then
>
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