Hi,
Enclosed patch is an updated version, with proper credits to Matt

Mackall and the Linux Tiny project.
Sincerly,
Thomas
---
Turn CONFIG_DMI into a selectable option if EMBEDDED is defined, in

order to be able to remove the DMI table scanning code if it's not

needed, and then reduce the kernel code size.
With CONFIG_DMI (i.e before) :
   text    data     bss     dec     hex filename

1076076  128656   98304 1303036  13e1fc vmlinux
Without CONFIG_DMI (i.e after) :
   text    data     bss     dec     hex filename

1068092  126308   98304 1292704  13b9a0 vmlinux
Result:
   text    data     bss     dec     hex filename

  -7984   -2348       0  -10332   -285c vmlinux
The new option appears in "Processor type and features", only when

CONFIG_EMBEDDED is defined.
This patch is part of the Linux Tiny project, and is based on previous

work done by Matt Mackall <mpm@selenic.com>.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---

 arch/x86/Kconfig    |   12 +++++++++---

 include/linux/dmi.h |    1 +

 2 files changed, 10 insertions(+), 3 deletions(-)
Index: linux/arch/x86/Kconfig

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

--- linux.orig/arch/x86/Kconfig	2008-02-11 16:51:50.000000000 +0100

+++ linux/arch/x86/Kconfig	2008-02-11 17:48:15.000000000 +0100

@@ -88,9 +88,6 @@

 config ARCH_MAY_HAVE_PC_FDC

 	def_bool y

=20

-config DMI

-	def_bool y

-

 config RWSEM_GENERIC_SPINLOCK

 	def_bool !X86_XADD

=20

@@ -433,6 +430,15 @@

=20

 # Mark as embedded because too many people got it wrong.

 # The code disables itself when not needed.

+config DMI

+	default y

+	bool "Enable DMI scanning" if EMBEDDED

+	help

+	  Enabled scanning of DMI to identify machine quirks. Say Y

+	  here unless you have verified that your setup is not

+	  affected by entries in the DMI black...
[ message continues ]

Question for Ingo...
On Tue, 12 Feb 2008 10:04:18 +0100
This introduces a build error in drivers/acpi/thermal.c, because that code

does:
#ifdef CONFIF_DMI

<define some tables>

#endif
	...

	dmi_check_system(<those tables>);
Now, the approved fix here is to just remove the ifdefs.  The !CONFIG_DMI

version of dmi_check_system() won't generate any references to the tables

and the build system is then supposed to remove the generated code and data

from vmlinux.
But this doesn't work.
When I add an ifdef around the dmi_check_system() call, I get
   text    data     bss     dec     hex filename

1614279  210524  159992 1984795  1e491b vmlinux
but when I remove the ifdefs around the tables and rely on the compiler

removing the code and data I get
   text    data     bss     dec     hex filename

1614447  210972  159992 1985411  1e4b83 vmlinux
An additional 616 bytes of useless stuff.
Ingo, I think there was some trick to making this work right.  Do you

recall?
--

Does bloat-o-meter say what the additional 616 bytes _is_?
scripts/bloat-o-meter vmlinux.old vmlinux.new
P.S.  What busybox did:
    ifneq ($(strip $(CONFIG_DEBUG)),y)

        OPTIMIZATION+=$(call check_cc,

$(CC),-ffunction-sections -fdata-sections,)

        CHECKED_LDFLAGS += $(call check_ld,$(LD),--gc-sections,)

    endif
Tells gcc to put each function and each global into its own ELF section, and

then told the linker to garbage collect unused sections...
Rob

--

"One of my most productive days was throwing away 1000 lines of code."

  - Ken Thompson.

--

Thanks for working on this.
Acked-by: Matt Mackall <mpm@selenic.com>
--

Mathematics is the supreme nostalgia of our time.
--

On Tue, 12 Feb 2008 12:56:45 -0600
That should have been "Signed-off-by:".  I'll speculatively make that

change.

--

for the x86 bits:
Acked-by: Ingo Molnar <mingo@elte.hu>
	Ingo

--