2 * relocate - common relocation function for ARM U-Boot
4 * Copyright (c) 2013 Albert ARIBAUD <albert.u.boot@aribaud.net>
6 * See file CREDITS for list of people who contributed to this
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25 #include <linux/linkage.h>
28 * void relocate_code(addr_moni)
30 * This function relocates the monitor code.
33 * To prevent the code below from containing references with an R_ARM_ABS32
34 * relocation record type, we never refer to linker-defined symbols directly.
35 * Instead, we declare literals which contain their relative location with
36 * respect to relocate_code, and at run time, add relocate_code back to them.
40 mov r6, r0 /* save addr of destination */
42 ldr r0, =__image_copy_start /* r0 <- SRC &__image_copy_start */
43 subs r9, r6, r0 /* r9 <- relocation offset */
44 beq relocate_done /* skip relocation */
45 mov r1, r6 /* r1 <- scratch for copy loop */
46 adr r7, relocate_code /* r7 <- SRC &relocate_code */
47 ldr r2, =__image_copy_end /* r2 <- SRC &__image_copy_end */
50 ldmia r0!, {r10-r11} /* copy from source address [r0] */
51 stmia r1!, {r10-r11} /* copy to target address [r1] */
52 cmp r0, r2 /* until source end address [r2] */
56 * fix .rel.dyn relocations
58 ldr r2, _rel_dyn_start_ofs /* r2 <- __rel_dyn_start local ofs */
59 add r2, r2, r7 /* r2 <- SRC &__rel_dyn_start */
60 ldr r3, _rel_dyn_end_ofs /* r3 <- __rel_dyn_end local ofs */
61 add r3, r3, r7 /* r3 <- SRC &__rel_dyn_end */
63 ldr r0, [r2] /* r0 <- SRC location to fix up */
64 add r0, r0, r9 /* r0 <- DST location to fix up */
67 cmp r7, #23 /* relative fixup? */
69 /* ignore unknown type of fixup */
72 /* relative fix: increase location by offset */
77 add r2, r2, #8 /* each rel.dyn entry is 8 bytes */
83 /* ARMv4- don't know bx lr but the assembler fails to see that */
92 .word __rel_dyn_start - relocate_code
94 .word __rel_dyn_end - relocate_code
96 ENDPROC(relocate_code)