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

Andre Renaud andre at bluewatersys.com
Wed Feb 29 15:25:12 EST 2012


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?

Regards,
Andre



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