# OpenBSD's Hibernate



## Samuel Venable (May 6, 2021)

OpenBSD has hibernate now. Doesn't sound like it has much compatibility with different architectures yet. Would it be possible for FreeBSD to borrow code from that when it's in a more complete state so we may benefit from it as well? Or are the two OS's far too different for this to be a viable solution for FreeBSD to implement hibernate?

Just curious, no I won't be helping with this, it's beyond my level of expertise. However if it is at all viable, might be worth pursuing by someone who's much more experienced.


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## kpedersen (May 6, 2021)

I know they had suspend working quite reliably a while back. FreeBSD has since caught up pretty well. I can't quite see where they have recently had hibernate added. I thought that kind of came along with suspend.

As far as I know they are quite different though. Not only is the apm / acpi stuff different but suspend / hibernate support needs to be present in a number of drivers deeper down.


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## SirDice (May 6, 2021)

It should work reasonably well, but there are still some issues with third party kernel modules that will prevent it from working correctly at all times.


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## garry (May 8, 2021)

SirDice said:


> It should work reasonably well, but there are still some issues with third party kernel modules that will prevent it from working correctly at all times.


And that's the difference between FreeBSD and OpenBSD power and state management -- OpenBSD has no third-party kernel modules.  They have no loadable modules at all, everything is compiled into the kernel.  I suppose that is quite an advantage in keeping the entire system well-defined and controllable.  From my limited perspective I can't see that they lose much except proprietary code and security risks in the kernel.  It was a tough stance to take for OpenBSD (in 2014 I think) but maybe it has proven to be the "correct" approach (?)


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