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 <asm-offsets.h> 10#include <config.h> 11#include <linux/linkage.h> 12 13/* 14 * void relocate_code(addr_moni) 15 * 16 * This function relocates the monitor code. 17 * 18 * NOTE: 19 * To prevent the code below from containing references with an R_ARM_ABS32 20 * relocation record type, we never refer to linker-defined symbols directly. 21 * Instead, we declare literals which contain their relative location with 22 * respect to relocate_code, and at run time, add relocate_code back to them. 23 */ 24 25ENTRY(relocate_code) 26 ldr r1, =__image_copy_start /* r1 <- SRC &__image_copy_start */ 27 subs r4, r0, r1 /* r4 <- relocation offset */ 28 beq relocate_done /* skip relocation */ 29 ldr r2, =__image_copy_end /* r2 <- SRC &__image_copy_end */ 30 31copy_loop: 32 ldmia r1!, {r10-r11} /* copy from source address [r1] */ 33 stmia r0!, {r10-r11} /* copy to target address [r0] */ 34 cmp r1, r2 /* until source end address [r2] */ 35 blo copy_loop 36 37 /* 38 * fix .rel.dyn relocations 39 */ 40 ldr r2, =__rel_dyn_start /* r2 <- SRC &__rel_dyn_start */ 41 ldr r3, =__rel_dyn_end /* r3 <- SRC &__rel_dyn_end */ 42fixloop: 43 ldmia r2!, {r0-r1} /* (r0,r1) <- (SRC location,fixup) */ 44 and r1, r1, #0xff 45 cmp r1, #23 /* relative fixup? */ 46 bne fixnext 47 48 /* relative fix: increase location by offset */ 49 add r0, r0, r4 50 ldr r1, [r0] 51 add r1, r1, r4 52 str r1, [r0] 53fixnext: 54 cmp r2, r3 55 blo fixloop 56 57 /* 58 * Relocate the exception vectors 59 */ 60#ifdef CONFIG_HAS_VBAR 61 /* 62 * If the ARM processor has the security extensions, 63 * use VBAR to relocate the exception vectors. 64 */ 65 ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ 66 mcr p15, 0, r0, c12, c0, 0 /* Set VBAR */ 67#else 68 /* 69 * Copy the relocated exception vectors to the 70 * correct address 71 * CP15 c1 V bit gives us the location of the vectors: 72 * 0x00000000 or 0xFFFF0000. 73 */ 74 ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ 75 mrc p15, 0, r2, c1, c0, 0 /* V bit (bit[13]) in CP15 c1 */ 76 ands r2, r2, #(1 << 13) 77 ldreq r1, =0x00000000 /* If V=0 */ 78 ldrne r1, =0xFFFF0000 /* If V=1 */ 79 ldmia r0!, {r2-r8,r10} 80 stmia r1!, {r2-r8,r10} 81 ldmia r0!, {r2-r8,r10} 82 stmia r1!, {r2-r8,r10} 83#endif 84 85relocate_done: 86 87#ifdef __XSCALE__ 88 /* 89 * On xscale, icache must be invalidated and write buffers drained, 90 * even with cache disabled - 4.2.7 of xscale core developer's manual 91 */ 92 mcr p15, 0, r0, c7, c7, 0 /* invalidate icache */ 93 mcr p15, 0, r0, c7, c10, 4 /* drain write buffer */ 94#endif 95 96 /* ARMv4- don't know bx lr but the assembler fails to see that */ 97 98#ifdef __ARM_ARCH_4__ 99 mov pc, lr 100#else 101 bx lr 102#endif 103 104ENDPROC(relocate_code) 105