[Qemu-devel] Using QCOW2 with nand flashes.

[Qemu-devel] Using QCOW2 with nand flashes.

[sai pavan]

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Hi,

I am trying to implement fake disk images for emulating nand flashes.
I see the spares files are formed when the content is zeros. But for nand
flashes the content is all one's initially. It is difficult for me make a
sparse file with all ones.

Do any one have suggestions for this problem.

I am thinking of creating an nand flash file with all zeros and negating
the data at receiving end in qemu. So the input file will be null, but the
concept of all 1's be intact. But this will be confusing if some one likes
to compare the output bin files after a write. One should read the data
negating.

Regards,
Sai Pavan

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[Qemu-devel] Fwd: Using QCOW2 with nand flashes.

[sai pavan]

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Hi,

I am trying to implement fake disk images for emulating nand flashes.
I see the spares files are formed when the content is zeros. But for nand
flashes the content is all one's initially. It is difficult for me make a
sparse file with all ones.

Do any one have suggestions for this problem.

I am thinking of creating an nand flash file with all zeros and negating
the data at receiving end in qemu. So the input file will be null, but the
concept of all 1's be intact. But this will be confusing if some one likes
to compare the output bin files after a write. One should read the data
negating.

Regards,
Sai Pavan

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Re: [Qemu-devel] Fwd: Using QCOW2 with nand flashes.

[Peter Crosthwaite]

On Mon, Jul 6, 2015 at 11:54 PM, sai pavan <saipavanboddu@gmail.com> wrote:
>
> Hi,
>
> I am trying to implement fake disk images for emulating nand flashes.
> I see the spares files are formed when the content is zeros. But for nand
> flashes the content is all one's initially. It is difficult for me make a
> sparse file with all ones.
>
> Do any one have suggestions for this problem.
>
> I am thinking of creating an nand flash file with all zeros and negating the
> data at receiving end in qemu.

Could this be a feature of qcow or some other file format rather than
a NAND specific thing? It probably applies to other flash media.

Regards,
Peter

> So the input file will be null, but the
> concept of all 1's be intact. But this will be confusing if some one likes
> to compare the output bin files after a write. One should read the data
> negating.
>
> Regards,
> Sai Pavan
>
>
>

Re: [Qemu-devel] Fwd: Using QCOW2 with nand flashes.

[sai pavan]

On Tue, Jul 7, 2015 at 2:11 PM, Peter Crosthwaite
<peter.crosthwaite@xilinx.com> wrote:
> On Mon, Jul 6, 2015 at 11:54 PM, sai pavan <saipavanboddu@gmail.com> wrote:
>>
>> Hi,
>>
>> I am trying to implement fake disk images for emulating nand flashes.
>> I see the spares files are formed when the content is zeros. But for nand
>> flashes the content is all one's initially. It is difficult for me make a
>> sparse file with all ones.
>>
>> Do any one have suggestions for this problem.
>>
>> I am thinking of creating an nand flash file with all zeros and negating the
>> data at receiving end in qemu.
>
> Could this be a feature of qcow or some other file format rather than
> a NAND specific thing? It probably applies to other flash media.
Yeah, its for all flash devices. Could be useful to emulate a bigger
spi flash too.
Let me know if qemu has any similar implantation in blockdev.

Thanks,
Sai Pavan.
>
> Regards,
> Peter
>
>> So the input file will be null, but the
>> concept of all 1's be intact. But this will be confusing if some one likes
>> to compare the output bin files after a write. One should read the data
>> negating.
>>
>> Regards,
>> Sai Pavan
>>
>>
>>