Re: [PATCH 1/2] ARM: Add Kconfig option to use mkimage -T kernel_noload

[Russell King - ARM Linux <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>]

On Thu, Mar 01, 2012 at 09:25:12AM +1300, Andre Renaud wrote:
> Hi Russell,
> >> I may have missed part of this, but isn't one of the points regarding
> >> this that the zImage decompressor always runs with data cache disabled,
> > 
> > Most certainly not.  We've had the data cache enabled for years and
> > years.  And I mean 10+ years.  We may have been lacking support on
> > some CPUs, but that was because of lack of contributions.
> > 
> >> resulting in a slow decompress, where as if the U-Boot decompressor is
> >> used (ie, gzipping the Image, and telling U-Boot to decompress), then it
> >> can run with caches enabled, improving boot speed?
> > 
> > That's pure FUD.
> 
> I don't want to open a can of worms on this, and I certainly haven't
> looked into the image decompressor within the Linux kernel, but from a
> boot speed point of view we certainly see a significant speed
> improvement switching from zImage to gzipped-Image. Do you know which
> platforms include the data-cache support in the decompressor?

All.