[LinuxBIOS] [PATCH] v3: duplicate less code

[Carl-Daniel Hailfinger]

Hi,

some time ago, we decided that stage2 should share code with stage0
whenever possible. I have investigated the current situation and we
could do much better.
Example analysis for the qemu target in its current revision follows:

Shared functions/symbols:
die
gdt_limit
gdtptr
get_option_table
post_code
printk
rtc_init
sprintf

Duplicated functions:
size    name
0000001a delay
0000001a mdelay
0000000e udelay
00000027 memcmp
0000000f memcpy
000000d6 memcpy_helper
00000021 memmove
00000013 memset
00000007 rawpnp_enter_ext_func_mode
00000006 rawpnp_exit_ext_func_mode
00000015 rawpnp_set_enable
00000029 rawpnp_set_iobase
00000012 rawpnp_set_logical_device
0000000e rawpnp_write_config

We waste a total of 493 bytes.

Patch for *delay and mem* functions follows, saving 386 bytes.

Regards,
Carl-Daniel

To reduce code duplication, make sure STAGE2_*OBJ does not contain
any object already mentioned in STAGE0_*_OBJ.
Specifically, remove mem.o, delay.o, udelay_io.o from STAGE2_*OBJ.
This saves 386 bytes in stage2 (~240 bytes after LZMA compression).

In the future, automatically removing objects from STAGE2_OBJ which
are already included in STAGE0_OBJ will be the way to go.

Signed-off-by: Carl-Daniel Hailfinger

--- 
Index: LinuxBIOSv3/arch/x86/Makefile
===================================================================
--- LinuxBIOSv3/arch/x86/Makefile	(revision 512)
+++ LinuxBIOSv3/arch/x86/Makefile	(working copy)
@@ -167,11 +167,13 @@
 # Where should it be built, maybe in device/?
 #
 # TODO: This should be compressed with the default compressor.
+# To reduce code duplication, always make sure STAGE2_LIB_OBJ does not contain
+# any object already mentioned in STAGE0_LIB_OBJ.
 #

-STAGE2_LIB_OBJ       = stage2.o clog2.o mem.o tables.o delay.o compute_ip_checksum.o
+STAGE2_LIB_OBJ       = stage2.o clog2.o tables.o compute_ip_checksum.o

-STAGE2_ARCH_X86_OBJ  = archtables.o linuxbios_table.o udelay_io.o
+STAGE2_ARCH_X86_OBJ  = archtables.o linuxbios_table.o
 STAGE2_ARCH_X86_OBJ += pci_ops_auto.o pci_ops_conf1.o pci_ops_conf2.o
 STAGE2_ARCH_X86_OBJ += keyboard.o i8259.o isa-dma.o

[Carl-Daniel Hailfinger]

On 21.11.2007 15:39, Carl-Daniel Hailfinger wrote:
[explanation snipped, see original post]
> To reduce code duplication, make sure STAGE2_*OBJ does not contain
> any object already mentioned in STAGE0_*_OBJ.
> Specifically, remove mem.o, delay.o, udelay_io.o from STAGE2_*OBJ.
> This saves 386 bytes in stage2 (~240 bytes after LZMA compression).
>
> In the future, automatically removing objects from STAGE2_OBJ which
> are already included in STAGE0_OBJ will be the way to go.
>
> Signed-off-by: Carl-Daniel Hailfinger

Opinions?

Regards,
Carl-Daniel

[Stefan Reinauer]

Carl-Daniel Hailfinger schrieb:
> On 21.11.2007 15:39, Carl-Daniel Hailfinger wrote:
> [explanation snipped, see original post]
> > To reduce code duplication, make sure STAGE2_*OBJ does not contain
> > any object already mentioned in STAGE0_*_OBJ.
> > Specifically, remove mem.o, delay.o, udelay_io.o from STAGE2_*OBJ.
> > This saves 386 bytes in stage2 (~240 bytes after LZMA compression).
> >
> > In the future, automatically removing objects from STAGE2_OBJ which
> > are already included in STAGE0_OBJ will be the way to go.
> >
> > Signed-off-by: Carl-Daniel Hailfinger
>
> Opinions?

Yes. We should think about this again when we sorted out the inter-stage 
call issues.

Stefan

[Carl-Daniel Hailfinger]

On 25.11.2007 16:26, Stefan Reinauer wrote:
> Carl-Daniel Hailfinger schrieb:
> > On 21.11.2007 15:39, Carl-Daniel Hailfinger wrote:
> > [explanation snipped, see original post]
> > > To reduce code duplication, make sure STAGE2_*OBJ does not contain
> > > any object already mentioned in STAGE0_*_OBJ.
> > > Specifically, remove mem.o, delay.o, udelay_io.o from STAGE2_*OBJ.
> > > This saves 386 bytes in stage2 (~240 bytes after LZMA compression).
> > >
> > > In the future, automatically removing objects from STAGE2_OBJ which
> > > are already included in STAGE0_OBJ will be the way to go.
> > >
> > > Signed-off-by: Carl-Daniel Hailfinger
> >
> > Opinions?
>
> Yes. We should think about this again when we sorted out the inter-stage 
> call issues.

Now that these issues are mostly solved, can we consider an improved
patch to solve code duplication?

To reduce code duplication, make sure STAGE2_OBJ does not contain
any object already mentioned in STAGE0_OBJ.
This saves 386 bytes in qemu stage2 (~240 bytes after LZMA compression).

Build tested and runtime tested in Qemu.

Signed-off-by: Carl-Daniel Hailfinger

Index: LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile
===================================================================
--- LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile	(Revision 529)
+++ LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile	(Arbeitskopie)
@@ -198,11 +198,16 @@
 STAGE2_OBJ += $(obj)/util/x86emu/libx86emu.a $(LIBGCC_FILE_NAME)
 endif

-$(obj)/linuxbios.stage2.o $(obj)/linuxbios.stage2.map: $(obj)/stage0.init $(STAGE2_OBJ)
+# To reduce code duplication, always make sure STAGE2_OBJ does not contain
+# any object from STAGE0_OBJ.
+
+STAGE2_OBJ_NEEDED = $(filter-out $(STAGE0_OBJ), $(STAGE2_OBJ))
+
+$(obj)/linuxbios.stage2.o $(obj)/linuxbios.stage2.map: $(obj)/stage0.init $(STAGE2_OBJ_NEEDED)
    $(Q)# leave a .o with full symbols in it for debugging.
    $(Q)printf "  LD      $(subst $(shell pwd)/,,$(@))\n"
    $(Q)$(LD) -R $(obj)/stage0.o -Ttext 0x1000 --entry=stage2 \
-		  -o $(obj)/linuxbios.stage2.o $(STAGE2_OBJ)
+		  -o $(obj)/linuxbios.stage2.o $(STAGE2_OBJ_NEEDED)
    $(Q)$(NM) $(obj)/linuxbios.stage2.o | sort -u > $(obj)/linuxbios.stage2.map

#

[Carl-Daniel Hailfinger]

Comments? This has been sitting in my tree for a while.

Regards,
Carl-Daniel

On 28.11.2007 01:04, Carl-Daniel Hailfinger wrote:
> To reduce code duplication, make sure STAGE2_OBJ does not contain
> any object already mentioned in STAGE0_OBJ.
> This saves 386 bytes in qemu stage2 (~240 bytes after LZMA compression).
>
> Build tested and runtime tested in Qemu.
>
> Signed-off-by: Carl-Daniel Hailfinger
> Index: LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile
>
> --- LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile	(Revision 529)
> +++ LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile	(Arbeitskopie)
> @@ -198,11 +198,16 @@
>  STAGE2_OBJ += $(obj)/util/x86emu/libx86emu.a $(LIBGCC_FILE_NAME)
>  endif
>
> -$(obj)/linuxbios.stage2.o $(obj)/linuxbios.stage2.map: $(obj)/stage0.init $(STAGE2_OBJ)
> +# To reduce code duplication, always make sure STAGE2_OBJ does not contain
> +# any object from STAGE0_OBJ.
>
> +STAGE2_OBJ_NEEDED = $(filter-out $(STAGE0_OBJ), $(STAGE2_OBJ))
>
> +$(obj)/linuxbios.stage2.o $(obj)/linuxbios.stage2.map: $(obj)/stage0.init $(STAGE2_OBJ_NEEDED)
>    $(Q)# leave a .o with full symbols in it for debugging.
>    $(Q)printf "  LD      $(subst $(shell pwd)/,,$(@))\n"
>    $(Q)$(LD) -R $(obj)/stage0.o -Ttext 0x1000 --entry=stage2 \
>   -o $(obj)/linuxbios.stage2.o $(STAGE2_OBJ)
>   -o $(obj)/linuxbios.stage2.o $(STAGE2_OBJ_NEEDED)
> $(Q)$(NM) $(obj)/linuxbios.stage2.o | sort -u > $(obj)/linuxbios.stage2.map
>
> #

[Carl-Daniel Hailfinger]

To reduce code duplication, make sure STAGE2_OBJ does not contain
any object already mentioned in STAGE0_OBJ.
This saves 386 bytes in qemu stage2 (~240 bytes after LZMA compression).

Build tested and runtime tested in Qemu.

Signed-off-by: Carl-Daniel Hailfinger

Index: LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile
===================================================================
--- LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile	(Revision 539)
+++ LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile	(Arbeitskopie)
@@ -198,11 +198,16 @@
 STAGE2_OBJ += $(obj)/util/x86emu/libx86emu.a $(LIBGCC_FILE_NAME)
 endif

-$(obj)/linuxbios.stage2 $(obj)/linuxbios.stage2.map: $(obj)/stage0.init $(STAGE2_OBJ)
+# To reduce code duplication, always make sure STAGE2_OBJ does not contain
+# any object from STAGE0_OBJ.
+
+STAGE2_OBJ_NEEDED = $(filter-out $(STAGE0_OBJ), $(STAGE2_OBJ))
+
+$(obj)/linuxbios.stage2 $(obj)/linuxbios.stage2.map: $(obj)/stage0.init $(STAGE2_OBJ_NEEDED)
    $(Q)# leave a .o with full symbols in it for debugging.
    $(Q)printf "  LD      $(subst $(shell pwd)/,,$(@))\n"
    $(Q)$(LD) -R $(obj)/stage0.o -Ttext 0x1000 --entry=stage2 \
-		  -o $(obj)/linuxbios.stage2 $(STAGE2_OBJ)
+		  -o $(obj)/linuxbios.stage2 $(STAGE2_OBJ_NEEDED)
    $(Q)$(NM) $(obj)/linuxbios.stage2 | sort -u > $(obj)/linuxbios.stage2.map

#

[Peter Stuge]

On Wed, Dec 05, 2007 at 02:56:26AM +0100, Carl-Daniel Hailfinger wrote:
> To reduce code duplication, make sure STAGE2_OBJ does not contain
> any object already mentioned in STAGE0_OBJ.
> This saves 386 bytes in qemu stage2 (~240 bytes after LZMA compression).
>
> Build tested and runtime tested in Qemu.
>
> Signed-off-by: Carl-Daniel Hailfinger

Acked-by: Peter Stuge

[Carl-Daniel Hailfinger]

On 05.12.2007 04:59, Peter Stuge wrote:
> On Wed, Dec 05, 2007 at 02:56:26AM +0100, Carl-Daniel Hailfinger wrote:
> > To reduce code duplication, make sure STAGE2_OBJ does not contain
> > any object already mentioned in STAGE0_OBJ.
> > This saves 386 bytes in qemu stage2 (~240 bytes after LZMA compression).
> >
> > Build tested and runtime tested in Qemu.
> >
> > Signed-off-by: Carl-Daniel Hailfinger
>
> Acked-by: Peter Stuge

Thanks, r540.

Regards,
Carl-Daniel