SunSolve Internal

Infodoc ID		Synopsis		Date
2160		How do I reconfigure the SunOS 4.x kernel?		16 Feb 2000

Description

Top

The UNIX kernel is the central controller of your SunOS Operating System, 
managing the use of memory, files, and devices. As such, the kernel is always 
in memory and running.

If you're a typical user, you may never need to reconfigure your kernel.The 
most common reason for reconfiguring a kernel is to support certain types of 
optional hardware or software added to your system. Hardware and software 
vendors usually make it easy to reconfigure your kernel by providing complete 
instructions. 

An experienced user may also rebuild the kernel to boost system performance, 
since the generic kernel shipped with the system includes some optional 
modules that can consume extra memory.

Following are instructions for reconfiguring your kernel.

Steps to generate a new kernel
------------------------------
1.Become superuser.

2.Change to the kernel configuration directory.
`Type a command similar to the following:

      # cd /usr/sys/<arch>/conf

Note that <arch> refers to the particular architecture of your 
machine. For example, the architecture type could be sun3, sun4,
or sun4c. Substitute the proper architecture type descriptor 
in place of <arch> in the above command.

You are now working in the directory containing the generic 
kernel configuration file, which is the configuration file 
installed on all new machines.

3.Check write permissions.

To make sure that you will be able to save changes in the 
directory, type the following command:

       # touch temp

If no error message appears, the directory is writable. Type 
rm temp to remove the test file. If you see a permission 
denied error message, Check, and if necessary, alter the
write permissions on the /usr directory. 

4.Copy the file GENERIC. 

Call the new file SYS_NAME,where SYS_NAME represents the 
name you want to give to your system. Use the following command:

  # cp GENERIC SYS_NAME

5.Change the permissions for SYS_NAME as follows:

  # chmod +w SYS_NAME

6.Make the necessary changes to SYS_NAME.

For guidelines, refer to the README file in the conf directory 
and see the pertinent sections in System and Network Administration. 

7.Rebuild the kernel.

           # config SYS_NAME

           # cd ../SYS_NAME

           # make

*** perform appropriate move and copy

        *** stand alone or server

          # mv /vmunix /vmunix.orig

          # cp vmunix /vmunix

        *** diskless client

          # mv /export/root/SYS_NAME/vmunix /export/root/SYS_NAME/vmunix.orig

          # cp vmunix /export/root/SYS_NAME/vmunix

        *** Dataless client

          # mv /vmunix /vmunix.orig

          # cp /usr/kvm/sys/sun[3,3x,4,4c]/SYS_NAME/vmunix /vmunix


8.Reboot the machine. Type:

  # /etc/reboot

If for some reason you are now unable to boot using the new kernel
you can always halt the machine (returning to the boot PROM prompt)
nd boot the original kernel:

> b vmunix.org


Additional Information on Reconfiguring Your Kernel
---------------------------------------------------
For more information, see System and Network Administration. 
Useful search terms in AnswerBook include:
kernel reconfigure rebuild driver