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5191 | serge | 1 | /* This file is a modified version of 'a.out.h'. It is to be used in all |
2 | GNU tools modified to support the i80960 (or tools that operate on |
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3 | object files created by such tools). |
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4 | |||
6324 | serge | 5 | Copyright (C) 2001-2015 Free Software Foundation, Inc. |
5191 | serge | 6 | |
7 | This program is free software; you can redistribute it and/or modify |
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8 | it under the terms of the GNU General Public License as published by |
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9 | the Free Software Foundation; either version 3 of the License, or |
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10 | (at your option) any later version. |
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11 | |||
12 | This program is distributed in the hope that it will be useful, |
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13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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15 | GNU General Public License for more details. |
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16 | |||
17 | You should have received a copy of the GNU General Public License |
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18 | along with this program; if not, write to the Free Software |
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19 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
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20 | MA 02110-1301, USA. */ |
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21 | |||
22 | /* All i80960 development is done in a CROSS-DEVELOPMENT environment. I.e., |
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23 | object code is generated on, and executed under the direction of a symbolic |
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24 | debugger running on, a host system. We do not want to be subject to the |
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25 | vagaries of which host it is or whether it supports COFF or a.out format, |
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26 | or anything else. We DO want to: |
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27 | |||
28 | o always generate the same format object files, regardless of host. |
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29 | |||
30 | o have an 'a.out' header that we can modify for our own purposes |
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31 | (the 80960 is typically an embedded processor and may require |
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32 | enhanced linker support that the normal a.out.h header can't |
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33 | accommodate). |
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34 | |||
35 | As for byte-ordering, the following rules apply: |
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36 | |||
37 | o Text and data that is actually downloaded to the target is always |
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38 | in i80960 (little-endian) order. |
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39 | |||
40 | o All other numbers (in the header, symbols, relocation directives) |
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41 | are in host byte-order: object files CANNOT be lifted from a |
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42 | little-end host and used on a big-endian (or vice versa) without |
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43 | modification. |
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44 | ==> THIS IS NO LONGER TRUE USING BFD. WE CAN GENERATE ANY BYTE ORDER |
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45 | FOR THE HEADER, AND READ ANY BYTE ORDER. PREFERENCE WOULD BE TO |
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46 | USE LITTLE-ENDIAN BYTE ORDER THROUGHOUT, REGARDLESS OF HOST. <== |
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47 | |||
48 | o The downloader ('comm960') takes care to generate a pseudo-header |
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49 | with correct (i80960) byte-ordering before shipping text and data |
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50 | off to the NINDY monitor in the target systems. Symbols and |
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51 | relocation info are never sent to the target. */ |
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52 | |||
53 | #define BMAGIC 0415 |
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54 | /* We don't accept the following (see N_BADMAG macro). |
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55 | They're just here so GNU code will compile. */ |
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56 | #define OMAGIC 0407 /* old impure format */ |
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57 | #define NMAGIC 0410 /* read-only text */ |
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58 | #define ZMAGIC 0413 /* demand load format */ |
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59 | |||
60 | /* FILE HEADER |
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61 | All 'lengths' are given as a number of bytes. |
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62 | All 'alignments' are for relinkable files only; an alignment of |
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63 | 'n' indicates the corresponding segment must begin at an |
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64 | address that is a multiple of (2**n). */ |
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65 | struct external_exec |
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66 | { |
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67 | /* Standard stuff */ |
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68 | unsigned char e_info[4]; /* Identifies this as a b.out file */ |
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69 | unsigned char e_text[4]; /* Length of text */ |
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70 | unsigned char e_data[4]; /* Length of data */ |
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71 | unsigned char e_bss[4]; /* Length of uninitialized data area */ |
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72 | unsigned char e_syms[4]; /* Length of symbol table */ |
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73 | unsigned char e_entry[4]; /* Runtime start address */ |
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74 | unsigned char e_trsize[4]; /* Length of text relocation info */ |
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75 | unsigned char e_drsize[4]; /* Length of data relocation info */ |
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76 | |||
77 | /* Added for i960 */ |
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78 | unsigned char e_tload[4]; /* Text runtime load address */ |
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79 | unsigned char e_dload[4]; /* Data runtime load address */ |
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80 | unsigned char e_talign[1]; /* Alignment of text segment */ |
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81 | unsigned char e_dalign[1]; /* Alignment of data segment */ |
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82 | unsigned char e_balign[1]; /* Alignment of bss segment */ |
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83 | unsigned char e_relaxable[1];/* Assembled with enough info to allow linker to relax */ |
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84 | }; |
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85 | |||
86 | #define EXEC_BYTES_SIZE (sizeof (struct external_exec)) |
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87 | |||
88 | /* These macros use the a_xxx field names, since they operate on the exec |
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89 | structure after it's been byte-swapped and realigned on the host machine. */ |
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90 | #define N_BADMAG(x) (((x).a_info)!=BMAGIC) |
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91 | #define N_TXTOFF(x) EXEC_BYTES_SIZE |
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92 | #define N_DATOFF(x) ( N_TXTOFF(x) + (x).a_text ) |
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93 | #define N_TROFF(x) ( N_DATOFF(x) + (x).a_data ) |
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94 | #define N_TRELOFF N_TROFF |
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95 | #define N_DROFF(x) ( N_TROFF(x) + (x).a_trsize ) |
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96 | #define N_DRELOFF N_DROFF |
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97 | #define N_SYMOFF(x) ( N_DROFF(x) + (x).a_drsize ) |
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98 | #define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms ) |
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99 | #define N_DATADDR(x) ( (x).a_dload ) |
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100 | |||
101 | /* Address of text segment in memory after it is loaded. */ |
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102 | #if !defined (N_TXTADDR) |
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103 | #define N_TXTADDR(x) 0 |
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104 | #endif |
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105 | |||
106 | /* A single entry in the symbol table. */ |
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107 | struct nlist |
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108 | { |
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109 | union |
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110 | { |
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111 | char* n_name; |
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112 | struct nlist * n_next; |
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113 | long n_strx; /* Index into string table */ |
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114 | } n_un; |
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115 | |||
116 | unsigned char n_type; /* See below */ |
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117 | char n_other; /* Used in i80960 support -- see below */ |
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118 | short n_desc; |
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119 | unsigned long n_value; |
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120 | }; |
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121 | |||
122 | |||
123 | /* Legal values of n_type. */ |
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124 | #define N_UNDF 0 /* Undefined symbol */ |
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125 | #define N_ABS 2 /* Absolute symbol */ |
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126 | #define N_TEXT 4 /* Text symbol */ |
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127 | #define N_DATA 6 /* Data symbol */ |
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128 | #define N_BSS 8 /* BSS symbol */ |
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129 | #define N_FN 31 /* Filename symbol */ |
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130 | |||
131 | #define N_EXT 1 /* External symbol (OR'd in with one of above) */ |
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132 | #define N_TYPE 036 /* Mask for all the type bits */ |
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133 | #define N_STAB 0340 /* Mask for all bits used for SDB entries */ |
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134 | |||
135 | /* MEANING OF 'n_other' |
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136 | |||
137 | If non-zero, the 'n_other' fields indicates either a leaf procedure or |
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138 | a system procedure, as follows: |
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139 | |||
140 | 1 <= n_other <= 32 : |
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141 | The symbol is the entry point to a system procedure. |
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142 | 'n_value' is the address of the entry, as for any other |
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143 | procedure. The system procedure number (which can be used in |
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144 | a 'calls' instruction) is (n_other-1). These entries come from |
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145 | '.sysproc' directives. |
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146 | |||
147 | n_other == N_CALLNAME |
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148 | the symbol is the 'call' entry point to a leaf procedure. |
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149 | The *next* symbol in the symbol table must be the corresponding |
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150 | 'bal' entry point to the procedure (see following). These |
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151 | entries come from '.leafproc' directives in which two different |
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152 | symbols are specified (the first one is represented here). |
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153 | |||
154 | |||
155 | n_other == N_BALNAME |
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156 | the symbol is the 'bal' entry point to a leaf procedure. |
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157 | These entries result from '.leafproc' directives in which only |
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158 | one symbol is specified, or in which the same symbol is |
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159 | specified twice. |
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160 | |||
161 | Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry, |
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162 | but not every N_BALNAME entry must have an N_CALLNAME entry. */ |
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163 | #define N_CALLNAME ((char)-1) |
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164 | #define N_BALNAME ((char)-2) |
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165 | #define IS_CALLNAME(x) (N_CALLNAME == (x)) |
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166 | #define IS_BALNAME(x) (N_BALNAME == (x)) |
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167 | #define IS_OTHER(x) ((x)>0 && (x) <=32) |
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168 | |||
169 | #define b_out_relocation_info relocation_info |
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170 | struct relocation_info |
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171 | { |
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172 | int r_address; /* File address of item to be relocated. */ |
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173 | unsigned |
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174 | #define r_index r_symbolnum |
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175 | r_symbolnum:24, /* Index of symbol on which relocation is based, |
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176 | if r_extern is set. Otherwise set to |
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177 | either N_TEXT, N_DATA, or N_BSS to |
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178 | indicate section on which relocation is |
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179 | based. */ |
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180 | r_pcrel:1, /* 1 => relocate PC-relative; else absolute |
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181 | On i960, pc-relative implies 24-bit |
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182 | address, absolute implies 32-bit. */ |
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183 | r_length:2, /* Number of bytes to relocate: |
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184 | |||
185 | 1 => 2 bytes -- used for 13 bit pcrel |
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186 | 2 => 4 bytes. */ |
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187 | r_extern:1, |
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188 | r_bsr:1, /* Something for the GNU NS32K assembler. */ |
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189 | r_disp:1, /* Something for the GNU NS32K assembler. */ |
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190 | r_callj:1, /* 1 if relocation target is an i960 'callj'. */ |
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191 | r_relaxable:1; /* 1 if enough info is left to relax the data. */ |
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192 | };=32) |