u-boot/arch/arc/lib/relocate.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
*/
#include <common.h>
#include <elf.h>
#include <log.h>
#include <asm-generic/sections.h>
#include <asm/global_data.h>
extern ulong __image_copy_start;
extern ulong __ivt_start;
extern ulong __ivt_end;
extern ulong __text_end;
DECLARE_GLOBAL_DATA_PTR;
int copy_uboot_to_ram(void)
{
size_t len = (size_t)&__image_copy_end - (size_t)&__image_copy_start;
if (gd->flags & GD_FLG_SKIP_RELOC)
return 0;
memcpy((void *)gd->relocaddr, (void *)&__image_copy_start, len);
return 0;
}
int clear_bss(void)
{
ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
size_t len = (size_t)&__bss_end - (size_t)&__bss_start;
memset((void *)dst_addr, 0x00, len);
return 0;
}
/*
* Base functionality is taken from x86 version with added ARC-specifics
*/
int do_elf_reloc_fixups(void)
{
Elf32_Rela *re_src = (Elf32_Rela *)(&__rel_dyn_start);
Elf32_Rela *re_end = (Elf32_Rela *)(&__rel_dyn_end);
if (gd->flags & GD_FLG_SKIP_RELOC)
return 0;
debug("Section .rela.dyn is located at %08x-%08x\n",
(unsigned int)re_src, (unsigned int)re_end);
Elf32_Addr *offset_ptr_rom;
Elf32_Addr *offset_ptr_ram;
do {
/* Get the location from the relocation entry */
offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
/* Check that the location of the relocation is in .text */
if (offset_ptr_rom >= (Elf32_Addr *)&__image_copy_start &&
offset_ptr_rom < (Elf32_Addr *)&__image_copy_end) {
unsigned int val, do_swap = 0;
/* Switch to the in-RAM version */
offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
gd->reloc_off);
#ifdef __LITTLE_ENDIAN__
/* If location in ".text" section swap value */
if (((u32)offset_ptr_rom >= (u32)&__text_start &&
(u32)offset_ptr_rom <= (u32)&__text_end)
#if defined(__ARC700__) || defined(__ARC600__)
|| ((u32)offset_ptr_rom >= (u32)&__ivt_start &&
(u32)offset_ptr_rom <= (u32)&__ivt_end)
#endif
)
do_swap = 1;
#endif
debug("Patching value @ %08x (relocated to %08x)%s\n",
(unsigned int)offset_ptr_rom,
(unsigned int)offset_ptr_ram,
do_swap ? ", middle-endian encoded" : "");
/*
* Use "memcpy" because target location might be
* 16-bit aligned on ARC so we may need to read
* byte-by-byte. On attempt to read entire word by
* CPU throws an exception
*/
memcpy(&val, offset_ptr_ram, sizeof(int));
if (do_swap)
val = (val << 16) | (val >> 16);
/* Check that the target points into executable */
if (val < (unsigned int)&__image_copy_start ||
val > (unsigned int)&__image_copy_end) {
/* TODO: Use panic() instead of debug()
*
* For some reason GCC might generate
* fake relocation even for LD/SC of constant
* inderectly. See an example below:
* ----------------------->8--------------------
* static int setup_mon_len(void)
* {
* gd->mon_len = (ulong)&__bss_end - CONFIG_SYS_MONITOR_BASE;
* return 0;
* }
* ----------------------->8--------------------
*
* And that's what we get in the binary:
* ----------------------->8--------------------
* 10005cb4 <setup_mon_len>:
* 10005cb4: 193c 3f80 0003 2f80 st 0x32f80,[r25,60]
* 10005cb8: R_ARC_RELATIVE *ABS*-0x10000000
* 10005cbc: 7fe0 j_s.d [blink]
* 10005cbe: 700c mov_s r0,0
* ----------------------->8--------------------
*/
debug("Relocation target %08x points outside of image\n",
val);
}
val += gd->reloc_off;
if (do_swap)
val = (val << 16) | (val >> 16);
memcpy(offset_ptr_ram, &val, sizeof(int));
}
} while (++re_src < re_end);
return 0;
}