> paul wrote:
> > 
> > prlw1@cam.ac.uk (Patrick Welche) wrote:
> > 
> > > Undefined instruction 0xeca0420c @ 0x00006a20 in process login
> > > LDC/STC
> > > stc     p2, c4, [r0], #0x030!
> > >
> > > In the configuration I included
> > > options         COMPAT_43       # 4.3BSD compatibility.
> > > options         COMPAT_13       # NetBSD 1.3 compatibility.
> > > options         COMPAT_12       # NetBSD 1.2 compatibility.
> > >
> > > So, have I missed a compatibility option? I should be able to build
> > > the new userland with a new kernel and old compiler right?
> > 
> > Okay there are 2 issues here:
> 
> [...]
> 
> > BTW, what does gdb say when you run your program? You can probably safely
> > ignore the kernel warning message as to what the real problem is (Mark can
> > decode the rest of the message but mere mortals like the rest of us stand
> > no chance :)
> 
> gdb says exactly the same thing ;)
> 
> # gdb
> Undefined instruction 0xeca0420c @ 0x00006a20 in process gdb (pid 18)
> LDC/STC
> stc     p2, c4, [r0], #0x030!
> Illegal instruction - core dumped
> 


That's a SFMFD (store floating point multiple) instruction.  Do you have the ARMFPE enabled in your kernel configuration?  If not, then that would probably explain why this is failing.

Richard.