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https://github.com/brain-hackers/u-boot-brain
synced 2024-08-22 09:58:52 +09:00
![Alexey Brodkin](/assets/img/avatar_default.png)
Intention behind this work was elimination of as much assembly-written code as it is possible. In case of ARC we already have relocation fix-up implemented in C so why don't we use C for U-Boot copying, .bss zeroing etc. It turned out x86 uses pretty similar approach so we re-used parts of code in "board_f.c" initially implemented for x86. Now assembly usage during init is limited to stack- and frame-pointer setup before and after relocation. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: Simon Glass <sjg@chromium.org>
89 lines
2.2 KiB
C
89 lines
2.2 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/sections.h>
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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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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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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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/*
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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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