Re: new special filesystem for consideration in 2.6/2.7

[Steve Longerbeam <stevel@mvista.com>]

Pavel Machek wrote:

>Hi!
>
>  
>
>>(PRAMFS). It was originally developed for three major consumer
>>electronics companies for use in their smart cell phones
>>and other consumer devices.
>>
>>An intro to PRAMFS along with a technical specification
>>is at the SourceForge project web page at
>>http://pramfs.sourceforge.net/. A patch for 2.6.3 has
>>been released at the SF project site.
>>    
>>
>
>Well, I'd certainly love to see some usable linux cell phones. 
>(Well, one such beast in my pocket would probably be enough :-)
>(Is there a way to make linux cell phone without second
>cpu just for GSM stack?)
>

one of the chips used in their cell phones is the TI OMAP1510.
It has an embedded TMS320c55 DSP as well as an ARM 925.

>
>Comments about pramfs: RAM is not really random access,
>you'll find that doing byte-sized random reads is way slower
>than linear read,
>but you are right that it is very different from disk.
>
>
>How do you handle powerfail in the middle of write?
>

good question, I don't - not in software anyway. But the companies
I mentioned may have implemented some kind of h/w safe shutdown,
but I'm not sure.

>Do you run fsck or do you have some kind of logging?
>

If you mean journaling, no, pramfs is not a journaling fs.

And you're right, I still need to write an fsck for pramfs.
At this point there is no way to recover a corrupt fs.

Steve