Driver Update Disk discussion

[John Baldwin]

On Friday 25 February 2005 04:39 am, Peter Jeremy wrote:
> On Thu, 2005-Feb-24 17:59:19 -0700, Scott Long wrote:
> >- kernel option support.  How do we support vendor modules in a kernel
> >that might be compiled with PAE (rather common these days), SMP, MAC,
> >etc.  The loader and /boot infrastructure has no concept of this.  It's
> >highly important, though.
>
> AFAIK, PAE is only relevant on iA32.  I second the suggestion that PAE
> be treated as a distinct architecture for these purposes.
>
> INVARIANTS and WITNESS are the other options that impact ABI.  These
> are probably unnecessary on -RELEASE but it would be nice if people
> could build a kernel with WITNESS and not have it panic if they loaded
> a module that wasn't compiled with WITNESS (which I think it the
> current behaviour).

No, WITNESS is completely opaque to modules.  If a module uses a spin lock, 
there is extra trickiness involved, but that should really be a rare case.  
INVARIANTS modules work fine if INVARIANT_SUPPORT is in the kernel.  
INVARIANT_SUPPORT usually means that functions like _mtx_assert() are present 
in the kernel.  Perhaps INVARIANT_SUPPORT should simply be on by default.  
MUTEX_PROFILING is one option that changes the ABI, but that is purposeful as 
that's really a development tool.

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org