Installation guide

command. The −c ﬂag allows you to name an existing conﬁguration ﬁle,

which the /usr/sbin/doconfig program uses to build the kernel. To

build a new kernel using an existing conﬁguration ﬁle, follow these steps:

1. Log in as root or become the superuser and set your default directory

to the /usr/sys/conf directory.

2. Save a copy of the existing /vmunix ﬁle. If possible, save the ﬁle in the

root (/) directory, as follows:

# cp /vmunix /vmunix.save

If there are disk space constraints, you can save the kernel ﬁle in a ﬁle

system other than root. For example:

# cp /vmunix /usr/vmunix.save

3. Run the /usr/sbin/doconfig program specifying the name of the

target conﬁguration ﬁle with the −c ﬂag. For example on a system

named MYSYS, enter the following command:

# /usr/sbin/doconfig -c MYSYS

*** KERNEL CONFIGURATION AND BUILD PROCEDURE ***

Saving /usr/sys/conf/MYSYS as /usr/sys/conf/MYSYS.bck

4. Answer the following prompt to indicate whether or not you want to

edit the conﬁguration ﬁle:

Do you want to edit the configuration file? (y/n) [n]:

If you modiﬁed the conﬁguration ﬁle before you started this procedure,

indicate that you do not want to edit the conﬁguration ﬁle.

If you choose to edit the conﬁguration ﬁle, the /usr/sbin/doconfig

program invokes the editor speciﬁed by the EDITOR environment

variable.

For information about the conﬁguration ﬁle, see Section 5.5

After you ﬁnish editing the conﬁguration ﬁle, the

/usr/sbin/doconfig program builds a new kernel.

5. When the kernel conﬁguration and build completes without errors,

move the new vmunix ﬁle to /vmunix. On a system named MYSYS,

issue the following command:

# mv /usr/sys/MYSYS/vmunix /vmunix

6. Reboot the system as follows:

# /usr/sbin/shutdown -r now

Conﬁguring the Kernel 5–25