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      1 /*
      2  * ELF object machine specific format helpers
      3  *
      4  *  Copyright (C) 2004-2007  Michael Urman
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND OTHER CONTRIBUTORS ``AS IS''
     16  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR OTHER CONTRIBUTORS BE
     19  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     25  * POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #ifndef ELF_MACHINE_H_INCLUDED
     29 #define ELF_MACHINE_H_INCLUDED
     30 
     31 #define YASM_WRITE_32I_L(p, i) do {\
     32     assert(yasm_intnum_check_size(i, 32, 0, 2)); \
     33     yasm_intnum_get_sized(i, p, 4, 32, 0, 0, 0); \
     34     p += 4; } while (0)
     35 
     36 #define YASM_WRITE_64I_L(p, i) do {\
     37     assert(yasm_intnum_check_size(i, 64, 0, 2)); \
     38     yasm_intnum_get_sized(i, p, 8, 64, 0, 0, 0); \
     39     p += 8; } while (0)
     40 
     41 #define YASM_WRITE_64C_L(p, hi, lo) do {\
     42     YASM_WRITE_32_L(p, lo); \
     43     YASM_WRITE_32_L(p, hi); } while (0)
     44 
     45 #define YASM_WRITE_64Z_L(p, i)          YASM_WRITE_64C_L(p, 0, i)
     46 
     47 typedef int(*func_accepts_reloc)(size_t val, yasm_symrec *wrt);
     48 typedef void(*func_write_symtab_entry)(unsigned char *bufp,
     49                                        elf_symtab_entry *entry,
     50                                        yasm_intnum *value_intn,
     51                                        yasm_intnum *size_intn);
     52 typedef void(*func_write_secthead)(unsigned char *bufp, elf_secthead *shead);
     53 typedef void(*func_write_secthead_rel)(unsigned char *bufp,
     54                                        elf_secthead *shead,
     55                                        elf_section_index symtab_idx,
     56                                        elf_section_index sindex);
     57 
     58 typedef void(*func_handle_reloc_addend)(yasm_intnum *intn,
     59                                         elf_reloc_entry *reloc,
     60                                         unsigned long offset);
     61 typedef unsigned int(*func_map_reloc_info_to_type)(elf_reloc_entry *reloc);
     62 typedef void(*func_write_reloc)(unsigned char *bufp,
     63                                 elf_reloc_entry *reloc,
     64                                 unsigned int r_type,
     65                                 unsigned int r_sym);
     66 typedef void (*func_write_proghead)(unsigned char **bufpp,
     67                                     elf_offset secthead_addr,
     68                                     unsigned long secthead_count,
     69                                     elf_section_index shstrtab_index);
     70 
     71 enum {
     72     ELF_SSYM_SYM_RELATIVE = 1 << 0,
     73     ELF_SSYM_CURPOS_ADJUST = 1 << 1,
     74     ELF_SSYM_THREAD_LOCAL = 1 << 2
     75 };
     76 
     77 typedef struct {
     78     const char *name;       /* should be something like ..name */
     79     const int sym_rel;      /* symbol or section-relative? */
     80     const unsigned int reloc;   /* relocation type */
     81     const unsigned int size;    /* legal data size */
     82 } elf_machine_ssym;
     83 
     84 struct elf_machine_handler {
     85     const char *arch;
     86     const char *machine;
     87     const char *reloc_section_prefix;
     88     const unsigned long symtab_entry_size;
     89     const unsigned long symtab_entry_align;
     90     const unsigned long reloc_entry_size;
     91     const unsigned long secthead_size;
     92     const unsigned long proghead_size;
     93     func_accepts_reloc accepts_reloc;
     94     func_write_symtab_entry write_symtab_entry;
     95     func_write_secthead write_secthead;
     96     func_write_secthead_rel write_secthead_rel;
     97     func_handle_reloc_addend handle_reloc_addend;
     98     func_map_reloc_info_to_type map_reloc_info_to_type;
     99     func_write_reloc write_reloc;
    100     func_write_proghead write_proghead;
    101 
    102     elf_machine_ssym *ssyms;            /* array of "special" syms */
    103     const size_t num_ssyms;             /* size of array */
    104 
    105     const int bits;                     /* usually 32 or 64 */
    106 };
    107 
    108 #endif /* ELF_MACHINE_H_INCLUDED */
    109