[U-Boot] Starting compressed win CE kernel

[A. Geisreiter <ageisreiter@dh-electronics.de>]

Dear Jean-Christophe PLAGNIOL-VILLARD,

I tried to use the unzip command of U-Boot, to unzip a Win CE Kernel. If I
have a file size of roughly 10MB it takes 1 minute to uncompress the kernel.
This is too long for my application. I use an PXA270 CPU with 64MB SDRAM.
How can I make the unzip command faster? 
Description of my U-Boot application: At the moment I start Win CE from the
flash memory in roughly 25 seconds. But the image takes much space on the
flash, because I haven't compressed it at the moment. So I will use the zip
functionality of U-boot to save space on flash memory. But this is only
reasonable, if I can start the OS in roughly the same time as before. 

Thanks and regards,
Andreas Geisreiter

-----Urspr?ngliche Nachricht-----
Von: Wolfgang Denk [mailto:wd at denx.de] 
Gesendet: Freitag, 4. September 2009 14:17
An: A. Geisreiter
Cc: u-boot at lists.denx.de; Jean-Christophe Plagniol-Villard
Betreff: Re: [U-Boot] Starting compressed win CE kernel

Dear "A. Geisreiter",

In message <001701ca2d55$f30b6200$d9222600$@de> you wrote:
> 
> > What makes you think that the uncompression code used by bootm would
> > be any faster than the one used by unzip? It ain't faster, as it is
> > the very same code actually.
> 
> If bootm use the same code like the unzip command, then it couldn't be
> faster.

Indeed.

> But I have compressed a nk.bin Windows Image file with GZIP. Then I
> uncompressed the 10MB File with U-Boot. It takes roughly 1 minute. And
this
> is to much I think. What could I do to reduce the uncompression time? My
> hardware works with an PXA270 CPU.

You probably want to enable caches on your system, to get faster
performance. Jean-Christophe (on Cc:) claimed several times before
that he was working on such patches. Maybe you ask him when he will
post this stuff.

Best regards,

Wolfgang Denk

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