x86: unify arch/x86/boot/compressed/vmlinux_*.lds

Look at the:

	diff -u arch/x86/boot/compressed/vmlinux_*.lds

output and realize that they're basially exactly the same except for
trivial naming differences, and the fact that the 64-bit version has a
"pgtable" thing.

So unify them.

There's some trivial cleanup there (make the output format a Kconfig thing
rather than doing #ifdef's for it, and unify both 32-bit and 64-bit BSS
end to "_ebss", where 32-bit used to use the traditional "_end"), but
other than that it's really very mindless and straigt conversion.

For example, I think we should aim to remove "startup_32" vs "startup_64",
and just call it "startup", and get rid of one more difference. I didn't
do that.

Also, notice the comment in the unified vmlinux.lds.S talks about
"head_64" and "startup_32" which is an odd and incorrect mix, but that was
actually what the old 64-bit only lds file had, so the confusion isn't
new, and now that mixing is arguably more accurate thanks to the
vmlinux.lds.S file being shared between the two cases ;)

[ Impact: cleanup, unification ]

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/Kconfig

@@ -47,6 +47,11 @@ config X86
 	select HAVE_KERNEL_BZIP2
 	select HAVE_KERNEL_LZMA
 
+config OUTPUT_FORMAT
+	string
+	default "elf32-i386" if X86_32
+	default "elf64-x86-64" if X86_64
+
 config ARCH_DEFCONFIG
 	string
 	default "arch/x86/configs/i386_defconfig" if X86_32

arch/x86/boot/compressed/Makefile

@@ -19,7 +19,7 @@ KBUILD_AFLAGS  := $(KBUILD_CFLAGS) -D__ASSEMBLY__
 LDFLAGS := -m elf_$(UTS_MACHINE)
 LDFLAGS_vmlinux := -T
 
-$(obj)/vmlinux: $(src)/vmlinux_$(BITS).lds $(obj)/head_$(BITS).o $(obj)/misc.o $(obj)/piggy.o FORCE
+$(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o $(obj)/piggy.o FORCE
 	$(call if_changed,ld)
 	@:
 

arch/x86/boot/compressed/head_32.S

@@ -88,9 +88,9 @@ ENTRY(startup_32)
  * where decompression in place becomes safe.
  */
 	pushl %esi
-	leal _end(%ebp), %esi
-	leal _end(%ebx), %edi
-	movl $(_end - startup_32), %ecx
+	leal _ebss(%ebp), %esi
+	leal _ebss(%ebx), %edi
+	movl $(_ebss - startup_32), %ecx
 	std
 	rep
 	movsb
@@ -121,7 +121,7 @@ relocated:
  */
 	xorl %eax,%eax
 	leal _edata(%ebx),%edi
-	leal _end(%ebx), %ecx
+	leal _ebss(%ebx), %ecx
 	subl %edi,%ecx
 	cld
 	rep

arch/x86/boot/compressed/vmlinux_64.lds → arch/x86/boot/compressed/vmlinux.lds.S

@@ -1,6 +1,13 @@
-OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64")
+OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT)
+
+#ifdef CONFIG_X86_64
 OUTPUT_ARCH(i386:x86-64)
 ENTRY(startup_64)
+#else
+OUTPUT_ARCH(i386)
+ENTRY(startup_32)
+#endif
+
 SECTIONS
 {
 	/* Be careful parts of head_64.S assume startup_32 is at
@@ -38,11 +45,13 @@ SECTIONS
 		*(.bss)
 		*(.bss.*)
 		*(COMMON)
+#ifdef CONFIG_X86_64
 		. = ALIGN(8);
 		_end_before_pgt = . ;
 		. = ALIGN(4096);
 		pgtable = . ;
 		. = . + 4096 * 6;
+#endif
 		_ebss = .;
 	}
 }