| 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 |
| 3 | object files created by such tools). |
| 4 | |
| 5 | Copyright 2001 Free Software Foundation, Inc. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | /* All i80960 development is done in a CROSS-DEVELOPMENT environment. I.e., |
| 22 | object code is generated on, and executed under the direction of a symbolic |
| 23 | debugger running on, a host system. We do not want to be subject to the |
| 24 | vagaries of which host it is or whether it supports COFF or a.out format, |
| 25 | or anything else. We DO want to: |
| 26 | |
| 27 | o always generate the same format object files, regardless of host. |
| 28 | |
| 29 | o have an 'a.out' header that we can modify for our own purposes |
| 30 | (the 80960 is typically an embedded processor and may require |
| 31 | enhanced linker support that the normal a.out.h header can't |
| 32 | accommodate). |
| 33 | |
| 34 | As for byte-ordering, the following rules apply: |
| 35 | |
| 36 | o Text and data that is actually downloaded to the target is always |
| 37 | in i80960 (little-endian) order. |
| 38 | |
| 39 | o All other numbers (in the header, symbols, relocation directives) |
| 40 | are in host byte-order: object files CANNOT be lifted from a |
| 41 | little-end host and used on a big-endian (or vice versa) without |
| 42 | modification. |
| 43 | ==> THIS IS NO LONGER TRUE USING BFD. WE CAN GENERATE ANY BYTE ORDER |
| 44 | FOR THE HEADER, AND READ ANY BYTE ORDER. PREFERENCE WOULD BE TO |
| 45 | USE LITTLE-ENDIAN BYTE ORDER THROUGHOUT, REGARDLESS OF HOST. <== |
| 46 | |
| 47 | o The downloader ('comm960') takes care to generate a pseudo-header |
| 48 | with correct (i80960) byte-ordering before shipping text and data |
| 49 | off to the NINDY monitor in the target systems. Symbols and |
| 50 | relocation info are never sent to the target. */ |
| 51 | |
| 52 | #define BMAGIC 0415 |
| 53 | /* We don't accept the following (see N_BADMAG macro). |
| 54 | They're just here so GNU code will compile. */ |
| 55 | #define OMAGIC 0407 /* old impure format */ |
| 56 | #define NMAGIC 0410 /* read-only text */ |
| 57 | #define ZMAGIC 0413 /* demand load format */ |
| 58 | |
| 59 | /* FILE HEADER |
| 60 | All 'lengths' are given as a number of bytes. |
| 61 | All 'alignments' are for relinkable files only; an alignment of |
| 62 | 'n' indicates the corresponding segment must begin at an |
| 63 | address that is a multiple of (2**n). */ |
| 64 | struct external_exec |
| 65 | { |
| 66 | /* Standard stuff */ |
| 67 | unsigned char e_info[4]; /* Identifies this as a b.out file */ |
| 68 | unsigned char e_text[4]; /* Length of text */ |
| 69 | unsigned char e_data[4]; /* Length of data */ |
| 70 | unsigned char e_bss[4]; /* Length of uninitialized data area */ |
| 71 | unsigned char e_syms[4]; /* Length of symbol table */ |
| 72 | unsigned char e_entry[4]; /* Runtime start address */ |
| 73 | unsigned char e_trsize[4]; /* Length of text relocation info */ |
| 74 | unsigned char e_drsize[4]; /* Length of data relocation info */ |
| 75 | |
| 76 | /* Added for i960 */ |
| 77 | unsigned char e_tload[4]; /* Text runtime load address */ |
| 78 | unsigned char e_dload[4]; /* Data runtime load address */ |
| 79 | unsigned char e_talign[1]; /* Alignment of text segment */ |
| 80 | unsigned char e_dalign[1]; /* Alignment of data segment */ |
| 81 | unsigned char e_balign[1]; /* Alignment of bss segment */ |
| 82 | unsigned char e_relaxable[1];/* Assembled with enough info to allow linker to relax */ |
| 83 | }; |
| 84 | |
| 85 | #define EXEC_BYTES_SIZE (sizeof (struct external_exec)) |
| 86 | |
| 87 | /* These macros use the a_xxx field names, since they operate on the exec |
| 88 | structure after it's been byte-swapped and realigned on the host machine. */ |
| 89 | #define N_BADMAG(x) (((x).a_info)!=BMAGIC) |
| 90 | #define N_TXTOFF(x) EXEC_BYTES_SIZE |
| 91 | #define N_DATOFF(x) ( N_TXTOFF(x) + (x).a_text ) |
| 92 | #define N_TROFF(x) ( N_DATOFF(x) + (x).a_data ) |
| 93 | #define N_TRELOFF N_TROFF |
| 94 | #define N_DROFF(x) ( N_TROFF(x) + (x).a_trsize ) |
| 95 | #define N_DRELOFF N_DROFF |
| 96 | #define N_SYMOFF(x) ( N_DROFF(x) + (x).a_drsize ) |
| 97 | #define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms ) |
| 98 | #define N_DATADDR(x) ( (x).a_dload ) |
| 99 | |
| 100 | /* Address of text segment in memory after it is loaded. */ |
| 101 | #if !defined (N_TXTADDR) |
| 102 | #define N_TXTADDR(x) 0 |
| 103 | #endif |
| 104 | |
| 105 | /* A single entry in the symbol table. */ |
| 106 | struct nlist |
| 107 | { |
| 108 | union |
| 109 | { |
| 110 | char* n_name; |
| 111 | struct nlist * n_next; |
| 112 | long n_strx; /* Index into string table */ |
| 113 | } n_un; |
| 114 | |
| 115 | unsigned char n_type; /* See below */ |
| 116 | char n_other; /* Used in i80960 support -- see below */ |
| 117 | short n_desc; |
| 118 | unsigned long n_value; |
| 119 | }; |
| 120 | |
| 121 | |
| 122 | /* Legal values of n_type. */ |
| 123 | #define N_UNDF 0 /* Undefined symbol */ |
| 124 | #define N_ABS 2 /* Absolute symbol */ |
| 125 | #define N_TEXT 4 /* Text symbol */ |
| 126 | #define N_DATA 6 /* Data symbol */ |
| 127 | #define N_BSS 8 /* BSS symbol */ |
| 128 | #define N_FN 31 /* Filename symbol */ |
| 129 | |
| 130 | #define N_EXT 1 /* External symbol (OR'd in with one of above) */ |
| 131 | #define N_TYPE 036 /* Mask for all the type bits */ |
| 132 | #define N_STAB 0340 /* Mask for all bits used for SDB entries */ |
| 133 | |
| 134 | /* MEANING OF 'n_other' |
| 135 | |
| 136 | If non-zero, the 'n_other' fields indicates either a leaf procedure or |
| 137 | a system procedure, as follows: |
| 138 | |
| 139 | 1 <= n_other <= 32 : |
| 140 | The symbol is the entry point to a system procedure. |
| 141 | 'n_value' is the address of the entry, as for any other |
| 142 | procedure. The system procedure number (which can be used in |
| 143 | a 'calls' instruction) is (n_other-1). These entries come from |
| 144 | '.sysproc' directives. |
| 145 | |
| 146 | n_other == N_CALLNAME |
| 147 | the symbol is the 'call' entry point to a leaf procedure. |
| 148 | The *next* symbol in the symbol table must be the corresponding |
| 149 | 'bal' entry point to the procedure (see following). These |
| 150 | entries come from '.leafproc' directives in which two different |
| 151 | symbols are specified (the first one is represented here). |
| 152 | |
| 153 | |
| 154 | n_other == N_BALNAME |
| 155 | the symbol is the 'bal' entry point to a leaf procedure. |
| 156 | These entries result from '.leafproc' directives in which only |
| 157 | one symbol is specified, or in which the same symbol is |
| 158 | specified twice. |
| 159 | |
| 160 | Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry, |
| 161 | but not every N_BALNAME entry must have an N_CALLNAME entry. */ |
| 162 | #define N_CALLNAME ((char)-1) |
| 163 | #define N_BALNAME ((char)-2) |
| 164 | #define IS_CALLNAME(x) (N_CALLNAME == (x)) |
| 165 | #define IS_BALNAME(x) (N_BALNAME == (x)) |
| 166 | #define IS_OTHER(x) ((x)>0 && (x) <=32) |
| 167 | |
| 168 | #define b_out_relocation_info relocation_info |
| 169 | struct relocation_info |
| 170 | { |
| 171 | int r_address; /* File address of item to be relocated. */ |
| 172 | unsigned |
| 173 | #define r_index r_symbolnum |
| 174 | r_symbolnum:24, /* Index of symbol on which relocation is based, |
| 175 | if r_extern is set. Otherwise set to |
| 176 | either N_TEXT, N_DATA, or N_BSS to |
| 177 | indicate section on which relocation is |
| 178 | based. */ |
| 179 | r_pcrel:1, /* 1 => relocate PC-relative; else absolute |
| 180 | On i960, pc-relative implies 24-bit |
| 181 | address, absolute implies 32-bit. */ |
| 182 | r_length:2, /* Number of bytes to relocate: |
| 183 | 0 => 1 byte |
| 184 | 1 => 2 bytes -- used for 13 bit pcrel |
| 185 | 2 => 4 bytes. */ |
| 186 | r_extern:1, |
| 187 | r_bsr:1, /* Something for the GNU NS32K assembler. */ |
| 188 | r_disp:1, /* Something for the GNU NS32K assembler. */ |
| 189 | r_callj:1, /* 1 if relocation target is an i960 'callj'. */ |
| 190 | r_relaxable:1; /* 1 if enough info is left to relax the data. */ |
| 191 | }; |