Thinning out GENERIC

[John Baldwin]

On Monday, February 13, 2017 10:51:36 AM Warner Losh wrote:
> [[ It isn't just GENERIC, it's in every single kernel ]]
> 
> On Sun, Feb 12, 2017 at 7:59 AM, Sean Bruno <sbruno at freebsd.org> wrote:
> > Index: sys/conf/files
> > ===================================================================
> > --- sys/conf/files      (revision 313683)
> > +++ sys/conf/files      (working copy)
> > @@ -2419,7 +2419,7 @@
> >  dev/pci/pci_user.c             optional pci
> >  dev/pci/pcib_if.m              standard
> >  dev/pci/pcib_support.c         standard
> > -dev/pci/vga_pci.c              optional pci
> > +#dev/pci/vga_pci.c             optional pci
> >  dev/pcn/if_pcn.c               optional pcn pci
> >  dev/pdq/if_fea.c               optional fea eisa
> >  dev/pdq/if_fpa.c               optional fpa pci
> >
> > I'm playing around with small x86 builds and wanted to come up with a
> > knob that disables the vga_pci driver.  Obviously I still want pci(4) to
> > be enabled, but I definitely do not need the vga interfaces for
> > anything.  Any suggestions?
> 
> You could make it dependent on vt or sc as well as pci, no?

This is a fairly small driver:

     6139      340         8      6487     0x1957   /usr/obj/usr/src/sys/GENERIC
/vga_pci.o

(From an 11.0-stable build)

device ppc and friends is a lot more for example:

  text   data   bss    dec      hex   filename
  6238      0     0   6238   0x185e   /usr/obj/usr/src/sys/GENERIC/ppb_1284.o
  1675     28     0   1703    0x6a7   /usr/obj/usr/src/sys/GENERIC/ppb_base.o
  2042      0     0   2042    0x7fa   /usr/obj/usr/src/sys/GENERIC/ppb_msq.o
  6025    296     8   6329   0x18b9   /usr/obj/usr/src/sys/GENERIC/ppbconf.o
     0    168     0    168     0xa8   /usr/obj/usr/src/sys/GENERIC/ppbus_if.o
  9099     36     0   9135   0x23af   /usr/obj/usr/src/sys/GENERIC/ppc.o
   495    256     0    751    0x2ef   /usr/obj/usr/src/sys/GENERIC/ppc_acpi.o
  1671    256     0   1927    0x787   /usr/obj/usr/src/sys/GENERIC/ppc_isa.o
  1124    208     0   1332    0x534   /usr/obj/usr/src/sys/GENERIC/ppc_pci.o
   451    208     0    659    0x293   /usr/obj/usr/src/sys/GENERIC/ppc_puc.o
  2751    428     8   3187    0xc73   /usr/obj/usr/src/sys/GENERIC/ppi.o

It is needed for drm.

-- 
John Baldwin