x86: introduce kernel/head32.c

Copy x86_64 and add a head32.c so we can start moving early
architecture initialization out of assembly.

[ Sam Ravnborg <sam@ravnborg.org>: updated it to x86 ]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/Makefile

@@ -159,9 +159,9 @@ KBUILD_AFLAGS += $(mflags-y)
 ###
 # Kernel objects
 
-head-y                := arch/x86/kernel/head_$(BITS).o
-head-$(CONFIG_X86_64) += arch/x86/kernel/head64.o
-head-y                += arch/x86/kernel/init_task.o
+head-y := arch/x86/kernel/head_$(BITS).o
+head-y += arch/x86/kernel/head$(BITS).o
+head-y += arch/x86/kernel/init_task.o
 
 libs-y  += arch/x86/lib/
 

arch/x86/kernel/Makefile

@@ -2,8 +2,7 @@
 # Makefile for the linux kernel.
 #
 
-extra-y                := head_$(BITS).o init_task.o vmlinux.lds
-extra-$(CONFIG_X86_64) += head64.o
+extra-y                := head_$(BITS).o head$(BITS).o init_task.o vmlinux.lds
 
 CPPFLAGS_vmlinux.lds += -U$(UTS_MACHINE)
 

arch/x86/kernel/head32.c

+/*
+ *  linux/arch/i386/kernel/head32.c -- prepare to run common code
+ *
+ *  Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
+ *  Copyright (C) 2007 Eric Biederman <ebiederm@xmission.com>
+ */
+
+#include <linux/init.h>
+#include <linux/start_kernel.h>
+
+void __init i386_start_kernel(void)
+{
+	start_kernel();
+}

arch/x86/kernel/head_32.S

@@ -450,7 +450,7 @@ is386:	movl $2,%ecx		# set MP
 	jmp initialize_secondary # all other CPUs call initialize_secondary
 1:
 #endif /* CONFIG_SMP */
-	jmp start_kernel
+	jmp i386_start_kernel
 
 /*
  * We depend on ET to be correct. This checks for 287/387.