cat file > /dev/mtd0 works but after position 512

cat file > /dev/mtd0 works but after position 512

[Indrek Kruusa]

Hi!

I have Samsung 64 MB NAND behind cs553x flash controller - therefore 
cs553x_nand driver.
cat file > /dev/mtd0 works reportedly (with page aligned file). But 
after board reboots the flash is empty.

dd ... bs=512 seek=1 of=/dev/mtd0  works and content stays in flash 
after reboot too (it works I mean :) )

I am debugging my own changes in cs553x_nand driver so it is up to me of 
course. But can this behavior be explained in other way than nand driver 
bug? Broken BIOS/board?

best regards,
Indrek

Re: cat file > /dev/mtd0 works but after position 512

[Thomas Gleixner]

On Tue, 2006-06-13 at 17:02 +0300, Indrek Kruusa wrote:
> Hi!
> 
> I have Samsung 64 MB NAND behind cs553x flash controller - therefore 
> cs553x_nand driver.
> cat file > /dev/mtd0 works reportedly (with page aligned file). But 
> after board reboots the flash is empty.
> 
> dd ... bs=512 seek=1 of=/dev/mtd0  works and content stays in flash 
> after reboot too (it works I mean :) )
> 
> I am debugging my own changes in cs553x_nand driver so it is up to me of 
> course. But can this behavior be explained in other way than nand driver 
> bug? Broken BIOS/board?

http://www.linux-mtd.infradead.org/faq/nand.html

	tglx

Re: cat file > /dev/mtd0 works but after position 512

[Indrek Kruusa]

Thomas Gleixner wrote:
> On Tue, 2006-06-13 at 17:02 +0300, Indrek Kruusa wrote:
>> Hi!
>>
>> I have Samsung 64 MB NAND behind cs553x flash controller - therefore 
>> cs553x_nand driver.
>> cat file > /dev/mtd0 works reportedly (with page aligned file). But 
>> after board reboots the flash is empty.
>>
>> dd ... bs=512 seek=1 of=/dev/mtd0  works and content stays in flash 
>> after reboot too (it works I mean :) )
>>
>> I am debugging my own changes in cs553x_nand driver so it is up to me of 
>> course. But can this behavior be explained in other way than nand driver 
>> bug? Broken BIOS/board?
>
> http://www.linux-mtd.infradead.org/faq/nand.html
>
> 	tglx

Thanks for the pointer - there are definitely still things I am not 
aware of. Currently it came out though that our BIOS contains support 
for NAND media with specific format. And if there isn't needed format in 
place - it creates one immediately at boot :)
Without that "feature" it seems to be OK. Annoying thing is that 
initializing says 'ECC error while reading bad block table'. I am not 
sure at moment how to handle this fact. But it is possible to 
flash_eraseall, nandwrite my_jffs2.img, mount and read it.

thanks,
Indrek