link_off calculates the difference between link address and
actila load address. This is a must for true PIC u-boot.
---
arch/powerpc/cpu/mpc83xx/start.S | 25 +++++++++++++++++++++++++
include/common.h | 5 +++++
2 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/cpu/mpc83xx/start.S b/arch/powerpc/cpu/mpc83xx/start.S
index 3cac147..ec65f40 100644
--- a/arch/powerpc/cpu/mpc83xx/start.S
+++ b/arch/powerpc/cpu/mpc83xx/start.S
@@ -427,6 +427,31 @@ _end_of_vectors:
. = 0x3000
+ .globl link_off /* const void * link_off(const void * ptr) */
+ .type link_off, @function
+ /*
+ * Calculates the offset between link address and load address
+ * and subtracs the offset to from its argument(r3)
+ * This function must be where _GOT2_TABLE_ is defined
+ */
+link_off:
+ /* GOT hand coded as we cannot clobber r12 */
+ mflr r4
+ bl 1f
+ .text 2
+0: .long .LCTOC1-1f
+ .text
+1: mflr r6
+ lwz r0,0b-1b(r6)
+ add r6,r0,r6
+ mtlr r4
+ la r4,.L__GOT2_TABLE_(r6) /* addi r4,r6,.L__GOT2_TABLE_ */
+ lwz r5,.L__GOT2_TABLE_(r6)
+ sub r4,r5,r4 /* r4 - r5 */
+ sub r3,r3,r4 /* r4 - r3 */
+ blr
+ .size link_off, .-link_off
+
/*
* This code finishes saving the registers to the exception frame
* and jumps to the appropriate handler for the exception.
diff --git a/include/common.h b/include/common.h
index 8bca04f..f257ea4 100644
--- a/include/common.h
+++ b/include/common.h
@@ -94,6 +94,9 @@ typedef volatile unsigned char vu_char;
#ifdef CONFIG_MPC83xx
#include <mpc83xx.h>
#include <asm/immap_83xx.h>
+const void * link_off(const void *);
+#else
+#define link_off(x) ((const void *)(x))
#endif
#ifdef CONFIG_4xx
#include <ppc4xx.h>
@@ -111,6 +114,8 @@ typedef volatile unsigned char vu_char;
#include <asm/arch/hardware.h>
#endif
+#define LINK_OFF(x) ((__typeof__(x))link_off(x))
+
#include <part.h>
#include <flash.h>
#include <image.h>
--
1.7.2.2
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