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Gordon Henderson wrote: > On Wed, 15 Jul 2009, Rob Beard wrote: > > <snip> >> Looks like Montavista have tailored a version of Linux which boots in >> less than 1.5 seconds. >> > Very impressive... > > I've recently built up a system to run under the AMD Geode processor - > 500MHz i686 look-a-like chip. > > Power on to boot is a few seconds. I could probably make it less, but I > can't turns off the memory test which prints progress out via a serial > line, then waits a second for the CF IDE drive to settle. > > So to boot - it needs to load a compressed bzImage off flash, then load a > compressed initrd.gz off the same flash, uncompress them then launch the > kernel. That alone takes some 5-10 seconds. > > Then the kernel starts - it takes a relatively long time to get through > all the kernel initialisation - CPU, memory, hardware (on-board IDE, > Ethernet, serial) Even in quick mode (no printout via the serial line) > this still takes some 20 seconds. > > Then /sbin/init starts and the usual /etc/init.d/xxx scripts get their > chance to initialise. > > So how can they get the entire kernel startup to a second?!? If I could > get power-on to /sbin/init down to under 10 seconds I'd be extremely > happy... > > Gordon > As far as I know (after watching the demo video) they use an uncompressed kernel with only drivers which the hardware requires and use DMA access to transfer the stuff into memory, I gather too that the hardware is pretty limited due to it being designed for in-car use. It also says that it has to be able to withstand the power being cut. I dare say that if it was to do other stuff other than the single task it's designed for then it would probably take longer to boot. Rob -- The Mailing List for the Devon & Cornwall LUG http://mailman.dclug.org.uk/listinfo/list FAQ: http://www.dcglug.org.uk/linux_adm/list-faq.html