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
-----Ursprüngliche Nachricht----- Von: Wolfgang Denk [mailto:wd@denx.de] Gesendet: Freitag, 4. September 2009 14:17 An: A. Geisreiter Cc: u-boot@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