On Wednesday 28 July 2010 10:59:53 pm Nicolas Luna wrote: > Hi guys, >
Hi, > I'm trying to make by board boot as quick as possible. I did some > optimisation with the "All This For 1 Second Boot" wiki and other website. > I would like to reduce a little bit more the boot time and I wonder if you > guys could give me some clues. > > I copied my boot log below. For sure I'll remove the uboot autoboot delay > and probably build a new kernel with modules. I putted in bold part that I > think it is possible to do more optimisation. > > 1- See bullet #3. > 2- The verifying Checksum is about 400 msec is it possible to skip it? Yes.(mentioned in an other reply) > 3- It takes ~1 sec to start booting the kernel and there is a other ~1 sec > delay between the starting kernel and the beginning of the uncompressing. > Why it's so long? Ok maybe there is the copy from NOR to RAM but it should > not take more than few msec. There can be some other optimizations in u-boot. For instance, there is one extra copy of kernel image which can be removed. You can use EDMA to increase flash to ram copy speed. When I did this for my nand, I was able to get maximum performance from my NAND flash, which was not possible without DMA. In that case, use of uncompressed image was more optimal. Otherwise decompressing kernel image was faster than transferring uncompressed kernel image from flash. Disadvantage of DMA was ECC wasn't working. But my favourite optimization was removing u-boot completely and booting Linux kernel from ubl directly. Though this is not an option for everyone. > 4- It takes ~1 sec to the kernel to free 120K memory... I got enought RAM > is it possible to remove it? > There is deferred init calls concept. Patches are present in [1]. Regards, Caglar [1] http://elinux.org/Deferred_Initcalls _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
