1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved. 4 */ 5 6 #include <common.h> 7 #include <elf.h> 8 #include <asm-generic/sections.h> 9 10 extern ulong __image_copy_start; 11 extern ulong __ivt_start; 12 extern ulong __ivt_end; 13 extern ulong __text_end; 14 15 DECLARE_GLOBAL_DATA_PTR; 16 17 int copy_uboot_to_ram(void) 18 { 19 size_t len = (size_t)&__image_copy_end - (size_t)&__image_copy_start; 20 21 if (gd->flags & GD_FLG_SKIP_RELOC) 22 return 0; 23 24 memcpy((void *)gd->relocaddr, (void *)&__image_copy_start, len); 25 26 return 0; 27 } 28 29 int clear_bss(void) 30 { 31 ulong dst_addr = (ulong)&__bss_start + gd->reloc_off; 32 size_t len = (size_t)&__bss_end - (size_t)&__bss_start; 33 34 memset((void *)dst_addr, 0x00, len); 35 36 return 0; 37 } 38 39 /* 40 * Base functionality is taken from x86 version with added ARC-specifics 41 */ 42 int do_elf_reloc_fixups(void) 43 { 44 Elf32_Rela *re_src = (Elf32_Rela *)(&__rel_dyn_start); 45 Elf32_Rela *re_end = (Elf32_Rela *)(&__rel_dyn_end); 46 47 if (gd->flags & GD_FLG_SKIP_RELOC) 48 return 0; 49 50 debug("Section .rela.dyn is located at %08x-%08x\n", 51 (unsigned int)re_src, (unsigned int)re_end); 52 53 Elf32_Addr *offset_ptr_rom; 54 Elf32_Addr *offset_ptr_ram; 55 56 do { 57 /* Get the location from the relocation entry */ 58 offset_ptr_rom = (Elf32_Addr *)re_src->r_offset; 59 60 /* Check that the location of the relocation is in .text */ 61 if (offset_ptr_rom >= (Elf32_Addr *)&__image_copy_start && 62 offset_ptr_rom < (Elf32_Addr *)&__image_copy_end) { 63 unsigned int val, do_swap = 0; 64 /* Switch to the in-RAM version */ 65 offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom + 66 gd->reloc_off); 67 68 #ifdef __LITTLE_ENDIAN__ 69 /* If location in ".text" section swap value */ 70 if (((u32)offset_ptr_rom >= (u32)&__text_start && 71 (u32)offset_ptr_rom <= (u32)&__text_end) 72 #if defined(__ARC700__) || defined(__ARC600__) 73 || ((u32)offset_ptr_rom >= (u32)&__ivt_start && 74 (u32)offset_ptr_rom <= (u32)&__ivt_end) 75 #endif 76 ) 77 do_swap = 1; 78 #endif 79 80 debug("Patching value @ %08x (relocated to %08x)%s\n", 81 (unsigned int)offset_ptr_rom, 82 (unsigned int)offset_ptr_ram, 83 do_swap ? ", middle-endian encoded" : ""); 84 85 /* 86 * Use "memcpy" because target location might be 87 * 16-bit aligned on ARC so we may need to read 88 * byte-by-byte. On attempt to read entire word by 89 * CPU throws an exception 90 */ 91 memcpy(&val, offset_ptr_ram, sizeof(int)); 92 93 if (do_swap) 94 val = (val << 16) | (val >> 16); 95 96 /* Check that the target points into executable */ 97 if (val < (unsigned int)&__image_copy_start || 98 val > (unsigned int)&__image_copy_end) { 99 /* TODO: Use panic() instead of debug() 100 * 101 * For some reason GCC might generate 102 * fake relocation even for LD/SC of constant 103 * inderectly. See an example below: 104 * ----------------------->8-------------------- 105 * static int setup_mon_len(void) 106 * { 107 * gd->mon_len = (ulong)&__bss_end - CONFIG_SYS_MONITOR_BASE; 108 * return 0; 109 * } 110 * ----------------------->8-------------------- 111 * 112 * And that's what we get in the binary: 113 * ----------------------->8-------------------- 114 * 10005cb4 <setup_mon_len>: 115 * 10005cb4: 193c 3f80 0003 2f80 st 0x32f80,[r25,60] 116 * 10005cb8: R_ARC_RELATIVE *ABS*-0x10000000 117 * 10005cbc: 7fe0 j_s.d [blink] 118 * 10005cbe: 700c mov_s r0,0 119 * ----------------------->8-------------------- 120 */ 121 debug("Relocation target %08x points outside of image\n", 122 val); 123 } 124 125 val += gd->reloc_off; 126 127 if (do_swap) 128 val = (val << 16) | (val >> 16); 129 130 memcpy(offset_ptr_ram, &val, sizeof(int)); 131 } 132 } while (++re_src < re_end); 133 134 return 0; 135 } 136