mtd emulation

mtd emulation

[Sam Pham]

I'd like to evaluate JFFS2.  Has anyone done this
before?  Does linux have the capability of emulating
mtd block device and mtd memory so that I can run
JFFS2 on top of it without using the actual flash?

Thanks.

Sam

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Re: mtd emulation

[Ralph Siemsen]

Sam Pham wrote:
> I'd like to evaluate JFFS2.  Has anyone done this
> before?  Does linux have the capability of emulating
> mtd block device and mtd memory so that I can run
> JFFS2 on top of it without using the actual flash?

I believe you can use MTD_MTDRAM for this.  There are a few associated 
parameters (total size, erase block size) to be fiddled as well.  See 
the the file linux-2.6.x/drivers/mtd/devices/mtdram.c

-R

Re: mtd emulation --> NAND?

[Charles Manning]

On Saturday 30 April 2005 09:24, Sam Pham wrote:
> I'd like to evaluate JFFS2.  Has anyone done this
> before?  Does linux have the capability of emulating
> mtd block device and mtd memory so that I can run
> JFFS2 on top of it without using the actual flash?
>

Further to this question, is there an emulation of NAND?

I use a "high level"  mtd NAND emulation that I wrote for YAFFS testing. This 
just provides the NAND mtd functions and uses none of the mtd.

I'm hoping there's a NAND emulation that emulates NAND at a very low level by 
accepting ALE/CLE and byte read/writes. This would provide, say, emulation of 
a 256Mbyte NAND part while exercising the whole of nand.c etc. This allows 
complete testing of file system + mtd code without having any hardware on 
hand.

-- Charles

Re: mtd emulation --> NAND?

[Artem B. Bityuckiy]

В Пнд, 02/05/2005 в 07:51 +1200, Charles Manning пишет:
> I use a "high level"  mtd NAND emulation that I wrote for YAFFS testing. This 
> just provides the NAND mtd functions and uses none of the mtd.
> 
> I'm hoping there's a NAND emulation that emulates NAND at a very low level by 
> accepting ALE/CLE and byte read/writes. This would provide, say, emulation of 
> a 256Mbyte NAND part while exercising the whole of nand.c etc. This allows 
> complete testing of file system + mtd code without having any hardware on 
> hand.
> 
You might take a look at drivers/mtd/nand/nandsim.c

It emulates NAND in RAM but I think it will be problematic to allocate
256 MiB of memory. But you may think of some trick... Nonetheless, I
used it to emulate 64MiB flashes and it works fine and even may emulate
some delays. I also may perform logging of NAND operations.

Cheers,
Artem.

-- 
Best Regards,
Artem B. Bityuckiy,
St.-Petersburg, Russia.