[beagleboard] Re: Bypassing U-Boot (SPL -> kernel)

Have you islolated what/where U-boot spends this time? Its hard to imagine what initialization could take that long. uncompressing and copying kernel into DDR should be the lions share of the time spent. I have seen RAM test on really slow really large older memories take a long time but this memory is modern. I think if you google this list there was talk about an easy way to profile/measure. I am spoiled using CCS to measure clock tick between breakpoints so I cant offer any ideas on how to measure beyond the painful old school way of scope and toggle gpio

— On Sat, 6/1/13, yllarest@gmail.com yllarest@gmail.com wrote:

> From: yllarest@gmail.com yllarest@gmail.com
> Subject: Re: [beagleboard] Re: Bypassing U-Boot (SPL → kernel)
> To: beagleboard@googlegroups.com
> Date: Saturday, June 1, 2013, 9:54 PM
> Well, it boils down to this:
> - Compile your rootfs with a uClibc toolchain
> - Remove unnecessary mounts
> - Use a static /dev
> - Disable all kernel debugging (really all of it)
> - Remove unnecessary functions from the kernel (depends on your needs)
> - Use busybox and compile just what you need
> - LZO compress your kernel
> - Use loglevel=0 as parameter for the kernel
> - Set lpj= as parameter for the kernel
> - Mount your FS as read-only (if necessary defer mounting as rw only after system is booted)
> - If possible, use SquashFS for the rootfs
> - Let go of using init and use your application as the initial process: (init= as parameter for the kernel)
> And so on… I still have to build a static /dev and use my app as the initial process (allowing me to remove all kinds of console from the kernel and rootfs [console=null as parameter for the kernel] so I think I still have headroom to reduce even more the boot time from the kernel). It’s really a shame that u-boot takes so long…
> So… is there a way to reduce even more the time it takes u-boot to run?
> –
> For more options, visit http://beagleboard.org/discuss
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