Didier Kryn <kryn@???> writes:

[...]

>>> Maybe you never shutdown, but some, like me, prefer to put their
>>> laptop back in a well-know state from time to time.
>>
>> Indeed, I do reboot from time to time. Sometimes it's because I
>> didn't keep an eye on battery state - it's getting towards the end of
>> it's life and I can no longer rely on the "low battery warning,
>> followed a while later by a forced sleep and suspend to disk" that
>> happens with a healthy battery. More often it's to clear memory -
>> something seems to have a leak, and I'm not that convinced OS X
>> memory management is all that good. But normally, I just use sleep
>> mode.
>

>     When I was testing a static build of vdev, I used to reboot my
> laptop several times per hour, alternatively to Debian Wheezy and to a
> minimalistic OS on a USB stick, containing essentially vdev and
> busybox. Reboot time is around 30s, yet it's still irritating.

>

>     Bios + Grub + kernel startup take by far the biggest part, but I
> think there's room for progress on these.

"To a degree": The three things wich take longest when booting my
workstation are

    - boot the kernel
        - get an address via DHCP
        - set the time via NTP

and none of these can be improved by changing the boot mechanics,
especially not by rewriting it all in a notoriously difficult to use
low-level language[*]. Booting will never become so fast that the time
wasted by doing so can be recouped.

[*] In the past, I was working on a Linux-based OS for an ARM9-based UTM
appliance. That booted in about 10s on a 200Mhz CPU using a boot system
almost entirely written in the Bourne shell language and executed by the
busybox ash. Considering this, it should be possibly to boot in
significantly less than 10s on anything currently considered "a
computer", embedded systems included, insofar the programming language
is concerned.