Reading currently running kernel configuration

[pbd]

Hi!

Is it possible to read configuration options for currently running kernel (without having the configuration file)? I need to find out if kernel was compiled with for example smp option.

Thanks in advance,

pbd

 

[FBSDin20Steps]

look here if that is what you are searching for...http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html
SMP is enabled by default in generic

 

[DutchDaemon]

In addition to that, there are some commands to find out what's in your kernel:

strings /boot/kernel/kernel
dmesg -a

There's also a kernel option to include the entire kernel config file in the kernel itself, but I'm drawing a pre-coffee blank atm.

 

[trev]

options INCLUDE_CONFIG_FILE

 

[DutchDaemon]

Yeah, I knew it was something totally unrecognisable

 

[pbd]

options INCLUDE_CONFIG_FILE

Thanks everybody. Where can I find the configuration, if I build kernel with this option? Is it just included in plain text in the kernel file?

 

[DutchDaemon]

Yes, strings will show it. At the top, I believe.

 

[vermaden]

also kldstat -v

 

[Mel_Flynn]

From sys/conf/NOTES:

strings -n3 /boot/kernel/kernel |sed -n 's/^__//p'

though, this seems to be broken on my -CURRENT machine.

 

[fronclynne]

A simple

> kldstat -v

will give you an idea of what devices are in the kernel, though if all you really want is to know if smp is on

> sysctl kern.smp
kern.smp.forward_roundrobin_enabled: 1
kern.smp.forward_signal_enabled: 1
kern.smp.topology: 0
kern.smp.cpus: 2
kern.smp.disabled: 0
kern.smp.active: 1
kern.smp.maxcpus: 32
kern.smp.maxid: 1

should suffice.

 

[ksb]

I realize this is a very old thread but a search for finding out if my kernel had the COMPAT_FREEBSD11 option on led me here. With the hints from above I've found that sysctl kern.conftxt yields the complete list of options and devices.

 

[SirDice]

With the hints from above I've found that sysctl kern.conftxt yields the complete list of options and devices.

Only if the kernel has been compiled with this option:

options         INCLUDE_CONFIG_FILE     # Include this file in kernel

 

[Eric A. Borisch]

Only if the kernel has been compiled with this option:

options         INCLUDE_CONFIG_FILE     # Include this file in kernel

Which, for the record, both GENERIC and MINIMAL set. (And has been since 2010 for "all non-embedded platforms".)