Resuming from a crashdump

[Ryan Sommers]

João Carlos Mendes Luís wrote:

> Isn't it much easier to simply reload the full memory dump (hibernation 
> file, not dump device) into RAM and continue from that point?  This 
> should be done by /boot/loader, not by a full kernel, as the memory dump 
> will also contain the kernel.
> 
> At this point, all you have to do is to restore the hardware state, 
> which may (or may not) be just the same as recovering from suspend state.

Restoring the hardware state requires restoring the state inside each 
and every hardware device. For certain devices this is trivial. However, 
I believe for devices with much more complex internal state machines 
this is way beyond the scope of the loader.

Now, that isn't to say the loader couldn't start executing the kernel 
somewhere other than "the beginning" and instead at a point where the 
kernel would specifically know it was awoken from hibernation and 
cleanup/reinitialize any devices.

My little knowledge on this subject aside. I'd love to have full 
suspend/resume functionality. It'd make my life as a mobile freebsd user 
much much easier. However, I wouldn't want it at the expense of every 
kernel. It would need to be something completely modular.


-- 
Ryan Sommers
ryans at gamersimpact.com