Re: How do GEOM_PART_* options configure geom_part_* modules??

> On Thu, Sep 28, 2017 at 11:12 AM, Kevin Oberman <rkoberman_at_gmail.com> wrote:
> 
> > On Thu, Sep 28, 2017 at 9:13 AM, Warner Losh <imp_at_bsdimp.com> wrote:
> >
> >> On Thu, Sep 28, 2017 at 10:00 AM, Nick Hibma <nick_at_van-laarhoven.org>
> >> wrote:
> >>
> >> > I created a new kernel config file from scratch, wondered what the
> >> > GEOM_PART_MBR option and friends were doing, search for them, didn't
> >> find
> >> > them in the tree, and deleted them from my config. But... de resulting
> >> disk
> >> > image didn't boot, because of the fact that it didn't recognise the MBR
> >> > partitions (it only had a single diskid entry on the mount-root prompt).
> >> >
> >> > Can anyone explain to me how these kernel options work, as in: they are
> >> > defined in kernel configs and as a consequence in opt_geom.h, but how
> >> are
> >> > they actually used to select which geom_part_* modules/kernel parts to
> >> > build? I thought these options were translated to stuff that cpp would
> >> use,
> >> > but there are not uses of for example GEOM_PART_MBR anywhere for
> >> example!
> >> >
> >> >
> >> > The module always build them because they are listed in the module's
> >> > Makefile.
> >> >
> >> > The kernel only sometimes does. Here's the key lines from conf/files:
> >> > files:geom/geom_bsd_enc.c optional geom_bsd | geom_part_bsd
> >> > files:geom/part/g_part_apm.c optional geom_part_apm
> >> > files:geom/part/g_part_bsd.c optional geom_part_bsd
> >> > files:geom/part/g_part_bsd64.c optional geom_part_bsd64
> >> > files:geom/part/g_part_ebr.c optional geom_part_ebr
> >> > files:geom/part/g_part_gpt.c optional geom_part_gpt
> >> > files:geom/part/g_part_ldm.c optional geom_part_ldm
> >> > files:geom/part/g_part_mbr.c optional geom_part_mbr
> >> > files:geom/part/g_part_vtoc8.c optional geom_part_vtoc8
> >> >
> >> > which turn on/off which files get included. config "helpfully" converts
> >> the
> >> > upper case options to lower case for this.
> >> >
> >> > Warner
> >> >
> >> >
> >> > *slaps forehead* Goose chase!
> >> >
> >> > I actually knew that... and, at the time, thought it was weird
> >> behaviour.
> >> > ''grep" would not have failed me if those options would be uppercase
> >> there
> >> > ...
> >> >
> >>
> >> I've been nibbled to death by these geese often enough to have a PTSD-like
> >> reaction when someone mentions it and habitually add -i to my greps...
> >>
> >> Warner
> >
> >
> > This horrid POLA violation seems to have been in FreeBSD configuration
> > since at least 3.0 and probably goes back to the creation of the
> > configuration process.
> >
> > Any idea why such a horrible POLA was ever introduced? Seems like an
> > obviously bad idea in an OS that is ALMOST always case sensitive.
> >
> 
> It's received code from the old 4.3 BSD config program (or maybe the net-2
> config program).

We had best not have any code direct from 4.3 or net-2, it should be from
4.4BSDLite, any code prior to that is subject of the lawsuit.


-- 
Rod Grimes                                                 rgrimes_at_freebsd.org