Proper way to compile custom kernel

Remington · Nov 6, 2012

What is the best way to compile the customized kernel after doing freebsd-update?

My method is:

Code:

# freebsd-update fetch
# freebsd-update install
# reboot
# freebsd-update install
# /usr/sbin/config -g CUSTOM
# cd /usr/src
# make buildkernel KERNCONF=CUSTOM
# make installkernel KERNCONF=CUSTOM
# reboot

UNIXgod · Nov 6, 2012

I've always used the method defined in the handbook:

kernel:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig-building.html

world:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html

I noticed no mergemaster in your steps. You may run into some issues.

TheDreamer · Nov 30, 2012

I thought mergemaster was only for remaking the world, and not needed when just making a custom kernel.

chatwizrd · Nov 30, 2012

You should get used to using shutdown -r now instead of reboot its a lot safer. The mergemaster just looks for changes in your config files. It usually isn't needed unless jumping major versions. Your commands look right, yet I have never used the /usr/sbin/config command before, I will have to look into that one.

UNIXgod · Nov 30, 2012

TheDreamer said:
I thought mergemaster was only for remaking the world, and not needed when just making a custom kernel.

It's part of the post upgrade activities which the op was asking about. I highly doubt freebsd-update automates that nor would I expect it to do it well.

kpa · Dec 1, 2012

chatwizrd said:
You should get used to using shutdown -r now instead of reboot its a lot safer. The mergemaster just looks for changes in your config files. It usually isn't needed unless jumping major versions. Your commands look right, yet I have never used the /usr/sbin/config command before, I will have to look into that one.

mergemaster(8) is absolutely needed if you're following a -STABLE branch, don't skip it if you are following one.

gkontos · Dec 1, 2012

@Remington,

You might want to have a look here for a custom kernel modification technique.

You should not run mergemaster() if you are using freebsd-update().

Like mentioned earlier, reboot() is not always the proper choice.

fmw · Dec 4, 2012

gkontos said:
@Remington,

Like mentioned earlier, reboot() is not always the proper choice.

What is the difference, aside from users being warned of the upcoming system halt/restart?

gkontos · Dec 4, 2012

fmw said:
What is the difference, aside from users being warned of the upcoming system halt/restart?

reboot(8)() will not call all shutdown command sequences while shutdown(8)() will. Therefore, it is better to use shutdown in multi user mode and reboot in single user mode.

bbzz · Dec 4, 2012

Something like
# make installkernel KERNCONF=CUSTOM KODIR=/boot/custom
# nextboot -k custom

can be useful, just in case.