Just how fast is barebox?

Just how fast is barebox?

[Geoff Smith]

[-- Attachment #1.1: Type: text/plain, Size: 669 bytes --]

Apologies for the newbie question. I am looking for a fastboot option for
 the i.MX27

I want to be capturing video data from a cold start within 300ms (preferably
200ms).

I have been looking at ThreadX etc which claims start-to-application-code in
300 cycles.

Until I ran across barebox I assumed that linux could not meet the
requirement.

So, does anyone out there have measured results for barebox that gets close
to my requirement?

If barebox/linux can't do it does anybody have a recommendation for a
suitable OS on iMX27 that can (off topic I know)

Regards
Geoff


-- 
*Geoff Smith
*
*Founder and CTO*
*gjsmith@vardr.com <mark@vardr.com>*
*+61 4 1200 7354
*

[-- Attachment #1.2: Type: text/html, Size: 1522 bytes --]

[-- Attachment #2: Type: text/plain, Size: 149 bytes --]

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

Re: Just how fast is barebox?

[Sascha Hauer]

Hi Geoff,

On Mon, Mar 28, 2011 at 01:25:18PM +1000, Geoff Smith wrote:
> Apologies for the newbie question. I am looking for a fastboot option for
>  the i.MX27
> 
> I want to be capturing video data from a cold start within 300ms (preferably
> 200ms).

The best I could get out of an i.MX27 was about 700ms. The main limiting
factor is how fast you can load an image from the boot medium (Nand
flash in my case). Given that I can read from Nand with 16MB/s a 5MB
image takes about 300ms to load. I think you'll need many dirty tricks
doing this with Linux, like a massively stripped down kernel and perhaps
starting the capture in the kernel (not in the application).

I wouldn't say it's not possible, but it's definitely a hard task.

Sascha


-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

Re: Just how fast is barebox?

[Geoff Smith]

[-- Attachment #1.1: Type: text/plain, Size: 1471 bytes --]

Thanks, very helpful info.

Looks like I may have to do something light weight like ecos.
I believe redboot is based on ecos so there may be a starting point there
for the i.mx27.

Regards
Geoff


On Mon, Mar 28, 2011 at 6:46 PM, Sascha Hauer <s.hauer@pengutronix.de>wrote:

> Hi Geoff,
>
> On Mon, Mar 28, 2011 at 01:25:18PM +1000, Geoff Smith wrote:
> > Apologies for the newbie question. I am looking for a fastboot option for
> >  the i.MX27
> >
> > I want to be capturing video data from a cold start within 300ms
> (preferably
> > 200ms).
>
> The best I could get out of an i.MX27 was about 700ms. The main limiting
> factor is how fast you can load an image from the boot medium (Nand
> flash in my case). Given that I can read from Nand with 16MB/s a 5MB
> image takes about 300ms to load. I think you'll need many dirty tricks
> doing this with Linux, like a massively stripped down kernel and perhaps
> starting the capture in the kernel (not in the application).
>
> I wouldn't say it's not possible, but it's definitely a hard task.
>
> Sascha
>
>
> --
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>



-- 
*Geoff Smith
*
*Founder and CTO*
*gjsmith@vardr.com <mark@vardr.com>*
*+61 4 1200 7354
*

[-- Attachment #1.2: Type: text/html, Size: 2683 bytes --]

[-- Attachment #2: Type: text/plain, Size: 149 bytes --]

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox