On Wed, Aug 19, 2009 at 06:20:13PM +0200, Dirk Behme wrote: >> >> Yes, correct. The copying itself is between 'copy' and 'done' so it >> takes about 0.4s. >> >>> What's the size of the uncompressed kernel copied here? >> >> The image is about 2.8MB, but I copied the whole partition of 3MB >> because with raw images you can't detect the image size. > > With 3MB copied in ~0.4s you get ~8MB/s. This really depends on your HW, > but I would think with standard NOR flashes you should be able to do at > least two (three?) times better. Have you already checked the memory (NOR > flash) timings configured in your SoC? It's NAND flash, so there's not much timing to optimize. What's interesting about this is that the kernel NAND driver is much slower than the one in U-Boot. Looking at it it turned out that the kernel driver uses interrupts to wait for the controller to get ready. Switching this to polling nearly doubles the NAND performance. UBI mounts much faster now and this cuts off another few seconds from the boot process :) Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
