mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-11 22:03:15 +00:00
264d298fda
Disabling relocation might be useful on ARC for 2 reasons:
a) For advanced debugging with Synopsys proprietary MetaWare debugger
which is capable of accessing much more specific hardware resources
compared to gdb. For example it may show contents of L1 and L2 caches,
internal states of some hardware blocks etc.
But on the downside MetaWare debugger still cannot work with PIE.
Even though that limitation could be work-arounded with change of ELF's
header and stripping down all debug info but with it we won't have
debug info for source-level debugging which is quite inconvenient.
b) Some platforms which might benefit from usage of U-Boot basically
don't have enough RAM to accommodate relocation of U-Boot so we
keep code in flash and use as much of RAM as possible for more
interesting things.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: York Sun <york.sun@nxp.com>
Cc: Stefan Roese <sr@denx.de>
104 lines
2.6 KiB
C
104 lines
2.6 KiB
C
/*
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* Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <elf.h>
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#include <asm-generic/sections.h>
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extern ulong __image_copy_start;
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extern ulong __ivt_end;
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DECLARE_GLOBAL_DATA_PTR;
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int copy_uboot_to_ram(void)
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{
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size_t len = (size_t)&__image_copy_end - (size_t)&__image_copy_start;
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if (gd->flags & GD_FLG_SKIP_RELOC)
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return 0;
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memcpy((void *)gd->relocaddr, (void *)&__image_copy_start, len);
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return 0;
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}
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int clear_bss(void)
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{
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ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
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size_t len = (size_t)&__bss_end - (size_t)&__bss_start;
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memset((void *)dst_addr, 0x00, len);
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return 0;
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}
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/*
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* Base functionality is taken from x86 version with added ARC-specifics
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*/
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int do_elf_reloc_fixups(void)
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{
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Elf32_Rela *re_src = (Elf32_Rela *)(&__rel_dyn_start);
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Elf32_Rela *re_end = (Elf32_Rela *)(&__rel_dyn_end);
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if (gd->flags & GD_FLG_SKIP_RELOC)
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return 0;
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debug("Section .rela.dyn is located at %08x-%08x\n",
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(unsigned int)re_src, (unsigned int)re_end);
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Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
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Elf32_Addr *offset_ptr_ram;
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do {
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/* Get the location from the relocation entry */
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offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
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/* Check that the location of the relocation is in .text */
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if (offset_ptr_rom >= (Elf32_Addr *)&__image_copy_start &&
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offset_ptr_rom > last_offset) {
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unsigned int val;
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/* Switch to the in-RAM version */
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offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
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gd->reloc_off);
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debug("Patching value @ %08x (relocated to %08x)\n",
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(unsigned int)offset_ptr_rom,
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(unsigned int)offset_ptr_ram);
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/*
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* Use "memcpy" because target location might be
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* 16-bit aligned on ARC so we may need to read
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* byte-by-byte. On attempt to read entire word by
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* CPU throws an exception
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*/
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memcpy(&val, offset_ptr_ram, sizeof(int));
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#ifdef __LITTLE_ENDIAN__
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/* If location in ".text" section swap value */
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if ((unsigned int)offset_ptr_rom <
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(unsigned int)&__ivt_end)
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val = (val << 16) | (val >> 16);
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#endif
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/* Check that the target points into executable */
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if (val >= (unsigned int)&__image_copy_start && val <=
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(unsigned int)&__image_copy_end) {
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val += gd->reloc_off;
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#ifdef __LITTLE_ENDIAN__
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/* If location in ".text" section swap value */
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if ((unsigned int)offset_ptr_rom <
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(unsigned int)&__ivt_end)
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val = (val << 16) | (val >> 16);
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#endif
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memcpy(offset_ptr_ram, &val, sizeof(int));
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}
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}
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last_offset = offset_ptr_rom;
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} while (++re_src < re_end);
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return 0;
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}
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