On Tue, Dec 2, 2014 at 8:02 PM, peter green plugwash@p10link.net wrote:
joem wrote:
What about an open sourced script that can do this feat? Everybody throws in their know how.
The problem is getting a fast boot time is really a matter of deciding what you can live without or at least start asyncronously after your main application has started, then ruthlessly optimising what is left for your specific case.
So the result is a system that boots to a specific application very quickly but may be horriblly broken if the application or hardware used changes.
there's a parallel init system i worked with that i adapted in 2006 to boot a 1.5ghz single-core pentium 3 system to x-windows in around 20 seconds. shutdown was under *three* seconds. instead of replacing udev i split the udevadm startup into two "settle" sections: one critical (disks, network, first 10 pseudo-ttys) and one-for-everything-else. x-windows and ssh were dependent on the one-for-everything-else, and networking, disk mounting etc were dependent on the critical one.
the only problem you've got with parallel init systems is that they rely on the processor being "modern" i.e. to have decent context-switching. an ARM9 is *NOT* a modern processor. every context-switch THROWS AWAY the cache. a Cortex A7 / A9 we might have better luck
l.