u-boot/arch/arc/lib/relocate.c
Alexey Brodkin ce3071287e ARC: Improve relocation fix-ups
We used to have the one and only linker script for all ARC boards
and so we relied on a particular order of symbols there.

Because of that we used __ivt_end as the marker of the end of all the
code which won't be true any longer if we move .ivt section to any other
place. That said we'd better check for each section separately.

A couple of other improvements:
 1. There's no point to include the marker of section end in interested
    range because its address is beyond the section, i.e. we should
    compare with "<" but not "<=".

 2. .ivt section for ARCv2 cores is just an array of 32-bit ints and
    they are not swapped even on little-endia cores while in case of
    ARCompact cores .ivt contains valid code so swapping is required.

 3. Just in case add check for ARC600 which is also ARCompact
    and its .ivt is normal code.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2018-05-31 20:13:29 +03:00

136 lines
3.7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
*/
#include <common.h>
#include <elf.h>
#include <asm-generic/sections.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;
}