Finding flash type...

Finding flash type...

[Siddharth Choudhuri]

Hi,

Is it possible to know what kind of flash (NOR type or
NAND type) is installed on a system ? (may be using
lsmod -or- cat /proc/ksyms | grep ? ) 

thanks,
-siddharth



 
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Re: Finding flash type...

[Ricard Wanderlof]

On Wed, 29 Nov 2006, Siddharth Choudhuri wrote:

> Is it possible to know what kind of flash (NOR type or
> NAND type) is installed on a system ? (may be using
> lsmod -or- cat /proc/ksyms | grep ? )

There is an ioctl (MEMGETINFO) that provides information on the type of 
flash memory among other info about the device. It is used by the 
mtd_debug utility which is part of the mtd-utils package, which dumps the 
information in human-readable form.

You can otherwise guess by checking the erasesize provided by
cat /proc/mtd, comparing the erasesize against expected erase sizes for 
the devices you expect to find. As a general solution this doesn't work 
well though.

/Ricard
--
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30

Re: Finding flash type...

[Artem Bityutskiy]

On Wed, 2006-11-29 at 10:53 -0800, Siddharth Choudhuri wrote:
> Hi,
> 
> Is it possible to know what kind of flash (NOR type or
> NAND type) is installed on a system ? (may be using
> lsmod -or- cat /proc/ksyms | grep ? ) 

It would be ideal if somebody added sysfs support to MTD. Then you could
just look at sysfs and find it out. Now you should use ioctl's.

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)

Re: Finding flash type...

[Siddharth Choudhuri]

--- Artem Bityutskiy <dedekind@infradead.org> wrote:
> It would be ideal if somebody added sysfs support to
> MTD. Then you could
> just look at sysfs and find it out. Now you should
> use ioctl's.
> 
I could start adding the sysfs support to reflect
flash type.  I have the following questions though:

1. Should the information be exported in the
/sys/block/mtd* directory ? The other place would be
/sys/class/mtd*. 

2. Should any other information be also exported ? The
mtd_info_user structure [include/mtd-abi.h] has
additional fields that might be useful - size,
erasesize, oobblock(if present) ? 

Any suggestions, pointers would be great. 

thanks,
-siddharth



 
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Re: Finding flash type...

[Josh Boyer]

On Tue, 2006-12-05 at 17:44 -0800, Siddharth Choudhuri wrote:
> --- Artem Bityutskiy <dedekind@infradead.org> wrote:
> > It would be ideal if somebody added sysfs support to
> > MTD. Then you could
> > just look at sysfs and find it out. Now you should
> > use ioctl's.
> >
> I could start adding the sysfs support to reflect
> flash type.  I have the following questions though:
> 
> 1. Should the information be exported in the
> /sys/block/mtd* directory ? The other place would be
> /sys/class/mtd*.

/sys/class/mtd would be preferable.  MTD isn't a block driver, so it
doesn't really belong under block.

> 2. Should any other information be also exported ? The
> mtd_info_user structure [include/mtd-abi.h] has
> additional fields that might be useful - size,
> erasesize, oobblock(if present) ?

Yes, most of mtd_info_user would be good to export.

josh

Re: Finding flash type...

[Ricard Wanderlof]

On Tue, 5 Dec 2006, Josh Boyer wrote:

>> 2. Should any other information be also exported ? The
>> mtd_info_user structure [include/mtd-abi.h] has
>> additional fields that might be useful - size,
>> erasesize, oobblock(if present) ?
>
> Yes, most of mtd_info_user would be good to export.

For NAND flash chips I think it would also be nice to get a list of bad 
blocks. This can be most useful when debugging.

/Ricard
--
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30

Re: Finding flash type...

[Artem Bityutskiy]

On Wed, 2006-12-06 at 09:31 +0100, Ricard Wanderlof wrote:
> For NAND flash chips I think it would also be nice to get a list of bad 
> blocks. This can be most useful when debugging.

Yeah. Once sysfs support is there we could export many useful
information without need to call these syscalls.

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)

Re: Finding flash type...

[Artem Bityutskiy]

On Tue, 2006-12-05 at 20:05 -0600, Josh Boyer wrote:
> > 1. Should the information be exported in the
> > /sys/block/mtd* directory ? The other place would be
> > /sys/class/mtd*.
> 

I am unsure it is /sys/class/. For MTD devices we should probably have
full device/driver/bus support so it'll go
at /sys/devices, /sys/drivers/, /sys/bus. In case of MTD the bus is so
called "platform" bus. Please, refer to linux device drivers v3.

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)