1 files changed, 112 insertions, 0 deletions
diff --git a/arch/arm/lib/relocate.S b/arch/arm/lib/relocate.S
new file mode 100644
index 0000000..4446da9
--- /dev/null
+++ b/arch/arm/lib/relocate.S
@@ -0,0 +1,112 @@
+/*
+ *  relocate - common relocation function for ARM U-Boot
+ *
+ *  Copyright (c) 2013  Albert ARIBAUD <albert.u.boot@aribaud.net>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <linux/linkage.h>
+
+/*
+ * void relocate_code(addr_moni)
+ *
+ * This function relocates the monitor code.
+ *
+ * NOTE:
+ * To prevent the code below from containing references with an R_ARM_ABS32
+ * relocation record type, we never refer to linker-defined symbols directly.
+ * Instead, we declare literals which contain their relative location with
+ * respect to relocate_code, and at run time, add relocate_code back to them.
+ */
+
+ENTRY(relocate_code)
+	mov	r6, r0	/* save addr of destination */
+
+	ldr	r0, =_start		/* r0 <- SRC &_start */
+	subs	r9, r6, r0		/* r9 <- relocation offset */
+	beq	relocate_done		/* skip relocation */
+	mov	r1, r6			/* r1 <- scratch for copy loop */
+	adr	r7, relocate_code	/* r7 <- SRC &relocate_code */
+	ldr	r3, _image_copy_end_ofs	/* r3 <- __image_copy_end local ofs */
+	add	r2, r7, r3		/* r2 <- SRC &__image_copy_end */
+
+copy_loop:
+	ldmia	r0!, {r10-r11}		/* copy from source address [r0]    */
+	stmia	r1!, {r10-r11}		/* copy to   target address [r1]    */
+	cmp	r0, r2			/* until source end address [r2]    */
+	blo	copy_loop
+
+	/*
+	 * fix .rel.dyn relocations
+	 */
+	ldr	r10, _dynsym_start_ofs	/* r10 <- __dynsym_start local ofs */
+	add	r10, r10, r7		/* r10 <- SRC &__dynsym_start */
+	ldr	r2, _rel_dyn_start_ofs	/* r2 <- __rel_dyn_start local ofs */
+	add	r2, r2, r7		/* r2 <- SRC &__rel_dyn_start */
+	ldr	r3, _rel_dyn_end_ofs	/* r3 <- __rel_dyn_end local ofs */
+	add	r3, r3, r7		/* r3 <- SRC &__rel_dyn_end */
+fixloop:
+	ldr	r0, [r2]		/* r0 <- SRC location to fix up */
+	add	r0, r0, r9		/* r0 <- DST location to fix up */
+	ldr	r1, [r2, #4]
+	and	r7, r1, #0xff
+	cmp	r7, #23			/* relative fixup? */
+	beq	fixrel
+	cmp	r7, #2			/* absolute fixup? */
+	beq	fixabs
+	/* ignore unknown type of fixup */
+	b	fixnext
+fixabs:
+	/* absolute fix: set location to (offset) symbol value */
+	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
+	add	r1, r10, r1		/* r1 <- address of symbol in table */
+	ldr	r1, [r1, #4]		/* r1 <- symbol value */
+	add	r1, r1, r9		/* r1 <- relocated sym addr */
+	b	fixnext
+fixrel:
+	/* relative fix: increase location by offset */
+	ldr	r1, [r0]
+	add	r1, r1, r9
+fixnext:
+	str	r1, [r0]
+	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
+	cmp	r2, r3
+	blo	fixloop
+
+relocate_done:
+
+	/* ARMv4- don't know bx lr but the assembler fails to see that */
+
+#ifdef __ARM_ARCH_4__
+        mov        pc, lr
+#else
+        bx        lr
+#endif
+
+_image_copy_end_ofs:
+	.word __image_copy_end - relocate_code
+_rel_dyn_start_ofs:
+	.word __rel_dyn_start - relocate_code
+_rel_dyn_end_ofs:
+	.word __rel_dyn_end - relocate_code
+_dynsym_start_ofs:
+	.word __dynsym_start - relocate_code
+
+ENDPROC(relocate_code)