1/* 2 * relocate - common relocation function for ARM U-Boot 3 * 4 * Copyright (c) 2013 Albert ARIBAUD <albert.u.boot@aribaud.net> 5 * 6 * SPDX-License-Identifier: GPL-2.0+ 7 */ 8 9#include <linux/linkage.h> 10 11/* 12 * void relocate_code(addr_moni) 13 * 14 * This function relocates the monitor code. 15 * 16 * NOTE: 17 * To prevent the code below from containing references with an R_ARM_ABS32 18 * relocation record type, we never refer to linker-defined symbols directly. 19 * Instead, we declare literals which contain their relative location with 20 * respect to relocate_code, and at run time, add relocate_code back to them. 21 */ 22 23ENTRY(relocate_code) 24 ldr r1, =__image_copy_start /* r1 <- SRC &__image_copy_start */ 25 subs r4, r0, r1 /* r4 <- relocation offset */ 26 beq relocate_done /* skip relocation */ 27 ldr r2, =__image_copy_end /* r2 <- SRC &__image_copy_end */ 28 29copy_loop: 30 ldmia r1!, {r10-r11} /* copy from source address [r1] */ 31 stmia r0!, {r10-r11} /* copy to target address [r0] */ 32 cmp r1, r2 /* until source end address [r2] */ 33 blo copy_loop 34 35 /* 36 * fix .rel.dyn relocations 37 */ 38 ldr r2, =__rel_dyn_start /* r2 <- SRC &__rel_dyn_start */ 39 ldr r3, =__rel_dyn_end /* r3 <- SRC &__rel_dyn_end */ 40fixloop: 41 ldmia r2!, {r0-r1} /* (r0,r1) <- (SRC location,fixup) */ 42 and r1, r1, #0xff 43 cmp r1, #23 /* relative fixup? */ 44 bne fixnext 45 46 /* relative fix: increase location by offset */ 47 add r0, r0, r4 48 ldr r1, [r0] 49 add r1, r1, r4 50 str r1, [r0] 51fixnext: 52 cmp r2, r3 53 blo fixloop 54 55relocate_done: 56 57#ifdef __XSCALE__ 58 /* 59 * On xscale, icache must be invalidated and write buffers drained, 60 * even with cache disabled - 4.2.7 of xscale core developer's manual 61 */ 62 mcr p15, 0, r0, c7, c7, 0 /* invalidate icache */ 63 mcr p15, 0, r0, c7, c10, 4 /* drain write buffer */ 64#endif 65 66 /* ARMv4- don't know bx lr but the assembler fails to see that */ 67 68#ifdef __ARM_ARCH_4__ 69 mov pc, lr 70#else 71 bx lr 72#endif 73 74ENDPROC(relocate_code) 75