# Re: direct access to Flash from userland

- From: Ankur Maheshwari \<hidden\>
- Date: 2008-09-08 06:06:56 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2008/09/9445917
- Thread: https://ratatoskr.run/linuxppc-dev/2008/09/9445895/t.md

```text
Dave Littell wrote:
> Arnd Bergmann wrote:
>   
>> On Thursday 04 September 2008, Fillod Stephane wrote:
>>     
>>>> Is there a way for a userland application to issue non-CFI commands
>>>> directly to a Flash device?  (This is a 2.6.18-based kernel on a AMCC
>>>> PPC440EPx platform.)
>>>>         
>>> I don't know whether there's specific ioctl for such purpose.
>>> Have you tried to read the mtd source? You may also hack the mtd
>>> layer to add your command. Definitely a question for http://www.linux-mtd.infradead.org/mail.html
>>>
>>>       
>> There is no ioctl command for sending arbitrary requests to the
>> flash, but it sounds like something that should be implemented
>> in the kernel, in mtdchar, depending on what the command does.
>>
>> What are you actually trying to do with those commands?
>>
>>     
>
> Hi Arnd,
>
> There are some sector protection options and a user-writable
> one-time-programmable section that's larger than the presently
> implemented 8-byte area that I need to support.
>
>
> Thanks,
> Dave
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>
>   
Hi Arnd,

You can consider "fw_env" utility (used for changing [read/write] U-boot environment variables from Linux) provided with u-boot source. You still need to enable mtd-char support.
Please check u-boot-source/tools/env directory for details.

thanks,
Ankur
```