Line data    Source code

       1              : /* arm ABI-specified defaults for DWARF CFI.
       2              :    Copyright (C) 2013 Red Hat, Inc.
       3              :    This file is part of elfutils.
       4              : 
       5              :    This file is free software; you can redistribute it and/or modify
       6              :    it under the terms of either
       7              : 
       8              :      * the GNU Lesser General Public License as published by the Free
       9              :        Software Foundation; either version 3 of the License, or (at
      10              :        your option) any later version
      11              : 
      12              :    or
      13              : 
      14              :      * the GNU General Public License as published by the Free
      15              :        Software Foundation; either version 2 of the License, or (at
      16              :        your option) any later version
      17              : 
      18              :    or both in parallel, as here.
      19              : 
      20              :    elfutils is distributed in the hope that it will be useful, but
      21              :    WITHOUT ANY WARRANTY; without even the implied warranty of
      22              :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      23              :    General Public License for more details.
      24              : 
      25              :    You should have received copies of the GNU General Public License and
      26              :    the GNU Lesser General Public License along with this program.  If
      27              :    not, see <http://www.gnu.org/licenses/>.  */
      28              : 
      29              : #ifdef HAVE_CONFIG_H
      30              : # include <config.h>
      31              : #endif
      32              : 
      33              : #include <dwarf.h>
      34              : 
      35              : #define BACKEND arm_
      36              : #include "libebl_CPU.h"
      37              : 
      38              : 
      39              : /* ABI-specified state of DWARF CFI based on:
      40              : 
      41              :    "DWARF for the ARM Architecture ABI r2.09"
      42              : http://infocenter.arm.com/help/topic/com.arm.doc.ihi0040b/IHI0040B_aadwarf.pdf
      43              : 
      44              :    "Procedure Call Standard for the ARM Architecture ABI r2.09"
      45              : http://infocenter.arm.com/help/topic/com.arm.doc.ihi0042e/IHI0042E_aapcs.pdf
      46              : */
      47              : 
      48              : int
      49            4 : arm_abi_cfi (Ebl *ebl __attribute__ ((unused)), Dwarf_CIE *abi_info)
      50              : {
      51            4 :   static const uint8_t abi_cfi[] =
      52              :     {
      53              :       /* The initial Canonical Frame Address is the value of the
      54              :          Stack Pointer (r13) as setup in the previous frame. */
      55              :       DW_CFA_def_cfa, ULEB128_7 (13), ULEB128_7 (0),
      56              : 
      57              :       /* The Stack Pointer (r13) is restored from CFA address by default.  */
      58              :       DW_CFA_val_offset, ULEB128_7 (13), ULEB128_7 (0),
      59              : 
      60              : #define SV(n) DW_CFA_same_value, ULEB128_7 (n)
      61              :       /* Callee-saved regs r4-r8, r10, r11.  */
      62              :       SV (4), SV (5), SV (6), SV (7), SV (8), SV (10), SV (11),
      63              : 
      64              :       /* The link register contains the return address setup by caller.  */
      65              :       SV (14),
      66              :       DW_CFA_register, ULEB128_7 (15), ULEB128_7 (14), /* pc = lr */
      67              : #undef SV
      68              : 
      69              :       /* VFP S16-S31/D8-D15/Q4-Q7 are callee saved.
      70              :          And uleb128 encoded with two bytes.  */
      71              : #define ULEB128_8_2(x) ((x & 0x7f) | 0x80), 0x02
      72              : #define SV(n) DW_CFA_same_value, ULEB128_8_2 (n)
      73              :       SV (264), SV (265), SV (266), SV (267),
      74              :       SV (268), SV (269), SV (270), SV (271),
      75              : 
      76              :       /* XXX Note: registers intentionally unused by the program,
      77              :          for example as a consequence of the procedure call standard
      78              :          should be initialized as if by DW_CFA_same_value.  */
      79              :     };
      80              : #undef ULEB128_8_2
      81              : #undef SV
      82              : 
      83            4 :   abi_info->initial_instructions = abi_cfi;
      84            4 :   abi_info->initial_instructions_end = &abi_cfi[sizeof abi_cfi];
      85            4 :   abi_info->data_alignment_factor = 4;
      86              : 
      87            4 :   abi_info->return_address_register = 15; /* pc.  */
      88              : 
      89            4 :   return 0;
      90              : }