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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2007,2008,2009 Free Software Foundation, Inc.
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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#if defined(MULTIBOOT_LOAD_ELF32)
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# define E_MACHINE MULTIBOOT_ELF32_MACHINE
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# define ELFCLASSXX ELFCLASS32
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# define Elf_Ehdr Elf32_Ehdr
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# define Elf_Phdr Elf32_Phdr
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#elif defined(MULTIBOOT_LOAD_ELF64)
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# define E_MACHINE MULTIBOOT_ELF64_MACHINE
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# define ELFCLASSXX ELFCLASS64
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# define Elf_Ehdr Elf64_Ehdr
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# define Elf_Phdr Elf64_Phdr
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#include <grub/i386/relocator.h>
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#define CONCAT(a,b) CONCAT_(a, b)
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#define CONCAT_(a,b) a ## b
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/* Check if BUFFER contains ELF32 (or ELF64). */
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CONCAT(grub_multiboot_is_elf, XX) (void *buffer)
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Elf_Ehdr *ehdr = (Elf_Ehdr *) buffer;
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return ehdr->e_ident[EI_CLASS] == ELFCLASSXX;
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CONCAT(grub_multiboot_load_elf, XX) (grub_file_t file, void *buffer)
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Elf_Ehdr *ehdr = (Elf_Ehdr *) buffer;
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int lowest_segment = -1, highest_segment = -1;
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grub_size_t code_size;
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if (ehdr->e_ident[EI_CLASS] != ELFCLASSXX)
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return grub_error (GRUB_ERR_UNKNOWN_OS, "invalid ELF class");
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if (ehdr->e_ident[EI_MAG0] != ELFMAG0
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|| ehdr->e_ident[EI_MAG1] != ELFMAG1
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|| ehdr->e_ident[EI_MAG2] != ELFMAG2
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|| ehdr->e_ident[EI_MAG3] != ELFMAG3
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|| ehdr->e_version != EV_CURRENT
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|| ehdr->e_ident[EI_DATA] != ELFDATA2LSB
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|| ehdr->e_machine != E_MACHINE)
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return grub_error(GRUB_ERR_UNKNOWN_OS, "no valid ELF header found");
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if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN)
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return grub_error (GRUB_ERR_UNKNOWN_OS, "invalid ELF file type");
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/* FIXME: Should we support program headers at strange locations? */
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if (ehdr->e_phoff + ehdr->e_phnum * ehdr->e_phentsize > MULTIBOOT_SEARCH)
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return grub_error (GRUB_ERR_BAD_OS, "program header at a too high offset");
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#if defined (MULTIBOOT_LOAD_ELF64) && defined (__mips)
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/* We still in 32-bit mode. */
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if (ehdr->e_entry < 0xffffffff80000000ULL)
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return grub_error (GRUB_ERR_BAD_OS, "invalid entry point for ELF64");
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/* We still in 32-bit mode. */
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if (ehdr->e_entry > 0xffffffff)
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return grub_error (GRUB_ERR_BAD_OS, "invalid entry point for ELF64");
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phdr_base = (char *) buffer + ehdr->e_phoff;
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#define phdr(i) ((Elf_Phdr *) (phdr_base + (i) * ehdr->e_phentsize))
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for (i = 0; i < ehdr->e_phnum; i++)
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if (phdr(i)->p_type == PT_LOAD && phdr(i)->p_filesz != 0)
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/* Beware that segment 0 isn't necessarily loadable */
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if (lowest_segment == -1
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|| phdr(i)->p_paddr < phdr(lowest_segment)->p_paddr)
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if (highest_segment == -1
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|| phdr(i)->p_paddr > phdr(highest_segment)->p_paddr)
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if (lowest_segment == -1)
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return grub_error (GRUB_ERR_BAD_OS, "ELF contains no loadable segments");
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code_size = (phdr(highest_segment)->p_paddr + phdr(highest_segment)->p_memsz) - phdr(lowest_segment)->p_paddr;
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grub_multiboot_payload_dest = phdr(lowest_segment)->p_paddr;
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grub_multiboot_pure_size += code_size;
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grub_multiboot_alloc_mbi = grub_multiboot_get_mbi_size () + 65536;
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grub_multiboot_payload_orig
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= grub_relocator32_alloc (grub_multiboot_pure_size + grub_multiboot_alloc_mbi);
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if (!grub_multiboot_payload_orig)
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/* Load every loadable segment in memory. */
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for (i = 0; i < ehdr->e_phnum; i++)
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if (phdr(i)->p_type == PT_LOAD && phdr(i)->p_filesz != 0)
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char *load_this_module_at = (char *) (grub_multiboot_payload_orig + (long) (phdr(i)->p_paddr - phdr(lowest_segment)->p_paddr));
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grub_dprintf ("multiboot_loader", "segment %d: paddr=0x%lx, memsz=0x%lx, vaddr=0x%lx\n",
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i, (long) phdr(i)->p_paddr, (long) phdr(i)->p_memsz, (long) phdr(i)->p_vaddr);
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if (grub_file_seek (file, (grub_off_t) phdr(i)->p_offset)
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return grub_error (GRUB_ERR_BAD_OS,
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"invalid offset in program header");
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if (grub_file_read (file, load_this_module_at, phdr(i)->p_filesz)
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!= (grub_ssize_t) phdr(i)->p_filesz)
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return grub_error (GRUB_ERR_BAD_OS,
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"couldn't read segment from file");
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if (phdr(i)->p_filesz < phdr(i)->p_memsz)
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grub_memset (load_this_module_at + phdr(i)->p_filesz, 0,
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phdr(i)->p_memsz - phdr(i)->p_filesz);
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for (i = 0; i < ehdr->e_phnum; i++)
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if (phdr(i)->p_vaddr <= ehdr->e_entry
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&& phdr(i)->p_vaddr + phdr(i)->p_memsz > ehdr->e_entry)
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grub_multiboot_payload_eip = grub_multiboot_payload_dest
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+ (ehdr->e_entry - phdr(i)->p_vaddr) + (phdr(i)->p_paddr - phdr(lowest_segment)->p_paddr);
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if (i == ehdr->e_phnum)
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return grub_error (GRUB_ERR_BAD_OS, "entry point isn't in a segment");