Any way to do time keeping during kernel uncompression[ARM architecture]

[sandeep kumar]

Dear All
FYI:
I got the below data in my board...
For Zimage:
Copy from eMMC to RAM(bootloader) & other stuff in bootloader -- 200msec
Kernel relocation --- 1msec
Kernel uncompression -- 700msec
Total time taken --- 900msec approx

For Image:
Copy from eMMC to RAM(bootloader) & other stuff in bootloader -- 1400msec

So in case of Uncompressed kernel image.. even though it doesnt need kernel
uncompression, it is taking 500msec more in bootloader.


Thanks
Sandeep





On Thu, Jan 31, 2013 at 12:46 PM, Dave Hylands <dhylands at gmail.com> wrote:

> Hi Sandeep
>
>
>
> On Wed, Jan 30, 2013 at 6:35 PM, sandeep kumar <coolsandyforyou at gmail.com>
> wrote:
> >
> > Hi Dave.
> > Ok
> > Can you tell me which thing runs faster ?
> > 1)Copy zImage(compressed kernel) from flash to Ram, jump to start,
> Relocate compress kernel, uncompress it...
> > 2)Copy Image(uncompressed one) from flash to RAM and run it right away...
> >
> > My gut feeling says second one is better, thats what i m trying to prove
> here... :)
>
> It depends on numerous factors:
> 1 - Your flash speed
> 2 - Your RAM speed
> 3 - Your CPU speed
> 4 - Whether you have code and/or data caches enabled
>
> If you enable the caches, use DMA from NAND (so make your NAND as fast as
> possible), then option 1 usually blows away option 2, but your mileage may
> vary.
>
> Dave Hylands
>



-- 
With regards,
Sandeep Kumar Anantapalli,
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