[PATCH] ppc64 boot: make the zImage relocateable

Make the zImage relocateable.  So yaboot could just load and run any ELF
binary, without worrying about its load address.

Signed-off-by: Olaf Hering <olh@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/ppc64/boot/crt0.S b/arch/ppc64/boot/crt0.S
index da6618a..5788a45 100644
--- a/arch/ppc64/boot/crt0.S
+++ b/arch/ppc64/boot/crt0.S
@@ -14,9 +14,38 @@
 	.text
 	.globl	_start
 _start:
+	bl	reloc_offset
+
+reloc_offset:
+	mflr	r0
+	lis	r9,reloc_offset@ha
+	addi	r9,r9,reloc_offset@l
+	subf.	r0,r9,r0
+	beq	clear_caches
+
+reloc_got2:
+	lis	r9,__got2_start@ha
+	addi	r9,r9,__got2_start@l
+	lis	r8,__got2_end@ha
+	addi	r8,r8,__got2_end@l
+	subf.	r8,r9,r8
+	beq	clear_caches
+	srwi.	r8,r8,2
+	mtctr	r8
+	add	r9,r0,r9
+reloc_got2_loop:
+	lwz	r8,0(r9)
+	add	r8,r8,r0
+	stw	r8,0(r9)
+	addi	r9,r9,4
+	bdnz	reloc_got2_loop
+
+clear_caches:
 	lis	r9,_start@h
+	add	r9,r0,r9
 	lis	r8,_etext@ha
 	addi	r8,r8,_etext@l
+	add	r8,r0,r8
 1:	dcbf	r0,r9
 	icbi	r0,r9
 	addi	r9,r9,0x20