How do I disable kdb?


You can disable kdb (the embedded kernel debugger) by setting the 800 bit on
the console boot register.  The following is a procedure for doing this.

First, take the system down.

        otis:root> init 0
        otis:root> 
        INIT: :New run level: 0
        The system is coming down.  Please wait.
        CPU 1 halted
        00181d44 [00000000] halt+44     00000000 0x00000000: invalid instruction
        CPU 0 halted
        001889d4 [001889d4] pause_self+b4  % 48000000 b pause_self+0xb4
        #0>

At the console prompt, display the current boot register value by typing
"pboot.".

        #0>pboot.00000080 

Set the boot register ORing 800 to the previous value.  For this example type
"pboot 880.".

        #0>pboot 880.00000080 

Restart the system.

        #0>fb
        Set Run Mode
          CPU 0  CPU 1
        dsk(0,0,0,0)/.
        dsk(0,0,0,0)/boot
        PowerMAX OS Boot Loader
        Boot
        : /stand/unix
        2871528+339223+504525 start 0x4000
        ...
        The system's name is otis.
        Welcome to Motorola PowerMAX_OS Release 4.3
        Console Login: 

To verify kdb is disabled, you can type "<return>~k".

        The system's name is otis.
        Welcome to Motorola PowerMAX_OS Release 4.3
        Console Login: ~CPU 0 halted
        00181d44 [00181d44] halt+44        % 7cc00124 mtmsr r6
        CPU 1 halted
        0010ebd8 [0010ebd8] idle+80          418afff8 beq+ crf2,idle+0x78
        #0>

Notice that instead of the kdb prompt we see the console prompt.
Type "r<return>" and you will return to the login.

        #0>r
            

        The system's name is otis.
        Welcome to Motorola PowerMAX_OS Release 4.3
        Console Login: 


To permanently disable kdb in a kernel, turn off the modules kdb and kdb_util
and rebuild the kernel.  The following is a procedure for doing this.

In directory /etc/conf/sdevice.d, edit kdb and kdb_util so the conf flag says
"N" instead of "Y".

Contents of /etc/conf/sdevice.d/kdb

        #ident  "@(#)kern-ibm:util/kdb/kdb/kdb.cf/System        1.5"
        #ident  "$Header: $"
        $version 1

        #name   conf    unit
        kdb     N       0

Contents of /etc/conf/sdevice.d/kdb_util 

        #ident  "@(#)kern-ibm:util/kdb/kdb_util/kdb_util.cf/System      1.6"
        #ident  "$Header: $"
        $version 1

        #name           conf    unit
        kdb_util        N       0

Rebuild and reboot the kernel.

        # /etc/conf/bin/idbuild
        # init 6
        ...


For more information see kdb(1), System(4), or the architecture specific
"Console Reference Manual".