cvs commit: src/sys/i386/i386 machdep.c

John Baldwin jhb at
Thu Mar 13 13:38:28 PDT 2008

On Thursday 13 March 2008 03:51:16 pm Rink Springer wrote:
> On Thu, Mar 13, 2008 at 06:56:53PM +0000, John Baldwin wrote:
> > jhb         2008-03-13 18:56:53 UTC
> > 
> >   FreeBSD src repository
> > 
> >   Modified files:
> >     sys/i386/i386        machdep.c 
> >   Log:
> >   Use the SMAP data from the loader if it is provided instead of using
> >   virtual 86 mode to query the BIOS directly.  This is needed for certain
> >   HP machines whose BIOS only provide an SMAP when invoked from real mode.
> >   On such machines the loader will be able to query the SMAP successfully
> >   due to the recent BTX changes, but the kernel will not.
> Thanks! I was thinking about doing this myself - seems you beat me to
> it.
> >   One thing I'm not sure of is if we can skip the INT 12h probe altogether
> >   if we have the SMAP from the loader as it seems that we do the INT 12h
> >   probe to setup enough state so we can use vm86 to call the BIOS.
> Hmm, can't we just have loader(8) pass this information as well? It
> seems it already does in the bootinfo structure...

I think people still want to be able to boot kernels from boot2/gptboot rather 
than loader in which case we'd always have to have the vm86 calls that are 
there now.

John Baldwin

More information about the cvs-src mailing list