[PATCH] i386: Relocatable kernel support

This patch modifies the i386 kernel so that if CONFIG_RELOCATABLE is
selected it will be able to be loaded at any 4K aligned address below
1G.  The technique used is to compile the decompressor with -fPIC and
modify it so the decompressor is fully relocatable.  For the main
kernel relocations are generated.  Resulting in a kernel that is relocatable
with no runtime overhead and no need to modify the source code.

A reserved 32bit word in the parameters has been assigned
to serve as a stack so we figure out where are running.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/i386/Makefile b/arch/i386/Makefile
index 0677908dfa06..d1aca52bf690 100644
--- a/arch/i386/Makefile
+++ b/arch/i386/Makefile
@@ -26,7 +26,9 @@ endif
 
 LDFLAGS         := -m elf_i386
 OBJCOPYFLAGS    := -O binary -R .note -R .comment -S
-LDFLAGS_vmlinux :=
+ifdef CONFIG_RELOCATABLE
+LDFLAGS_vmlinux := --emit-relocs
+endif
 CHECKFLAGS      += -D__i386__
 
 CFLAGS += -pipe -msoft-float