Subject: Re: direct access to Flash from userland

From: Ankur Maheshwari <[email-masked]>
Date: Mon, 08 Sep 2008 11:30:14 +0530

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
> _______________________________________________
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> [email-masked]
> 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