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-rw-r--r--arch/arm/lib/Makefile1
-rw-r--r--arch/arm/lib/relocate.S112
2 files changed, 113 insertions, 0 deletions
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 5b2cb61..8ad9f66 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -39,6 +39,7 @@ GLCOBJS += div0.o
SOBJS-y += crt0.o
ifndef CONFIG_SPL_BUILD
+SOBJS-y += relocate.o
ifndef CONFIG_SYS_GENERIC_BOARD
COBJS-y += board.o
endif
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)