On Thursday 15 October 2009 01:09:04 Steve Ressler wrote: > Hi, > Hi,
Is your mail client sending html messages by default? > I'm trying to get my boot time down under 2 seconds. I have followed the > steps listed at > http://wiki.davincidsp.com/index.php?title=All_This_For_1_Second_Boot and > this has gotten me to about 3-4 seconds. > > My question is that I am seeing a pause between the last output of u-boot > and the first output of the kernel which seems strange to me. This pause is > on the order of 1.5 seconds, which if I could eliminate would put me right > where I want to be. > > The output is shown below. The pause I am talking about happens between > "Starting kernel ..." and "Linux version 2.6.10_mv...." > I don't know the reason of delay but it is related to kernel, not u-boot. Here is the code related to this point from u-boot: /* we assume that the kernel is in place */ printf ("\nStarting kernel ...\n\n"); #ifdef CONFIG_USB_DEVICE { extern void udc_disconnect (void); udc_disconnect (); } #endif cleanup_before_linux (); theKernel (0, machid, bd->bi_boot_params); /* does not return */ return; And the cleanup_before_linux function is: int cleanup_before_linux (void) { /* * this function is called just before we call linux * it prepares the processor for linux * * we turn off caches etc ... */ unsigned long i; disable_interrupts (); /* turn off I/D-cache */ asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i)); i &= ~(C1_DC | C1_IC); asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i)); /* flush I/D-cache */ i = 0; asm ("mcr p15, 0, %0, c7, c7, 0": :"r" (i)); return (0); } theKernel function is the actual kernel image. So optimization must be done in the kernel. Regards, Caglar P.S. My u-boot version may be newer than yours but I verified same delay exists in my setup also. _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
