1/* 2 * relocate - common relocation function for ARM U-Boot 3 * 4 * Copyright (c) 2013 Albert ARIBAUD <albert.u.boot@aribaud.net> 5 * 6 * See file CREDITS for list of people who contributed to this 7 * project. 8 * 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. 13 * 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. 18 * 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, 22 * MA 02111-1307 USA 23 */ 24 25#include <linux/linkage.h> 26 27/* 28 * void relocate_code(addr_moni) 29 * 30 * This function relocates the monitor code. 31 * 32 * NOTE: 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. 37 */ 38 39ENTRY(relocate_code) 40 ldr r1, =__image_copy_start /* r1 <- SRC &__image_copy_start */ 41 subs r9, r0, r1 /* r9 <- relocation offset */ 42 beq relocate_done /* skip relocation */ 43 ldr r2, =__image_copy_end /* r2 <- SRC &__image_copy_end */ 44 45copy_loop: 46 ldmia r1!, {r10-r11} /* copy from source address [r1] */ 47 stmia r0!, {r10-r11} /* copy to target address [r0] */ 48 cmp r1, r2 /* until source end address [r2] */ 49 blo copy_loop 50 51 /* 52 * fix .rel.dyn relocations 53 */ 54 ldr r2, =__rel_dyn_start /* r2 <- SRC &__rel_dyn_start */ 55 ldr r3, =__rel_dyn_end /* r3 <- SRC &__rel_dyn_end */ 56fixloop: 57 ldmia r2!, {r0-r1} /* (r0,r1) <- (SRC location,fixup) */ 58 and r1, r1, #0xff 59 cmp r1, #23 /* relative fixup? */ 60 bne fixnext 61 62 /* relative fix: increase location by offset */ 63 add r0, r0, r9 64 ldr r1, [r0] 65 add r1, r1, r9 66 str r1, [r0] 67fixnext: 68 cmp r2, r3 69 blo fixloop 70 71relocate_done: 72 73 /* ARMv4- don't know bx lr but the assembler fails to see that */ 74 75#ifdef __ARM_ARCH_4__ 76 mov pc, lr 77#else 78 bx lr 79#endif 80 81ENDPROC(relocate_code) 82