On Fri, 18 Oct 1996, Hauke Fath wrote:

> > So, here is my question:
> > 
> > what options among 
> > 
> > options         M68040
> > options         M68030
> > options         M68020          # Must have 68851 PMMU
> > options         FPSP
> > options         FPU_EMULATE
> > 
> > are really options and what options must always be present?

M68040/M68030/M68020 are only useful for the appropriate CPU; the 020
_must_ have a 68851 PMMU.  You only need the single option necessary for
your CPU, if you are compiling for a specific machine.

FPSP is only used for the 040.

FPU_EMULATE is only needed for the 68LC040 and any machine that does not
have an 881/882 floating point processor.

I've tested all of these, but if something has recently slipped through
the cracks that I wasn't aware of, please tell me.  Note that I fixed
several problems quite some time ago (May?), and if locore.s (in
particular) hasn't been updated properly, you may run into problems such
as you describe.

> I noticed, though, that leaving out the SysV IPC options prevents the
> machine from rebooting: 'reboot' hangs when trying to sync disks, and
> 'shutdown -r now' shuts down the machine but fails to reboot.

News to me!  _HOWEVER_, if you don't compile a kernel with COMPAT_12
defined, you will have the problem you describe.  I suggest that you do a
`make clean' and recompile the kernel from scratch after adding this
option to your kernel config.

(You can verify that this is the problem by looking for a core dump of
shutdown, reboot, or halt in the directory you ran it from.)

--scott