[oe] Build uncompressed kernel

[Tom Rini]

On Tue, 2010-05-04 at 21:16 +0600, Dmitry Vinokurov wrote:
> Hello,
> 
> Is there any way to cancel compression stage of kernel build and get
> uncompressed uImage using OE? I've measured uncompressing time (using
> stopwatch actually, so it could be +-0.1-0.2 seconds or even more) -- it's
> about 0.8-0.9 seconds, and boot time is much more critical for my system
> than image size, so even 0.5 seconds is really important. Bootloader is
> Uboot, board is ARM9 Phytec lpc3250.
> 
> Also I've read http://elinux.org/About_Compression and it states about
> decompress time about 50ms, so looks like either I should measure boot time
> using more precise tools (like from inside of Uboot) or my board is not so
> fast as those which used by authors. Perhaps anybody could share their
> experience in this issue, is it worth at all to try to build uncompressed
> kernel?

Since we don't use the kernel's uImage rule, do_uboot_mkimage in
kernel.bbclass could be extended easily enough to check for a
NO_KERNEL_COMPRESSION variable or whatever and do or not do the gzip
(and pass the right arg to mkimage).

-- 
Tom Rini <tom_rini at mentor.com>
Mentor Graphics Corporation