| /* This file is a modified version of 'a.out.h'. It is to be used in all |
| GNU tools modified to support the i80960 (or tools that operate on |
| object files created by such tools). |
| |
| Copyright (C) 2001-2021 Free Software Foundation, Inc. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| MA 02110-1301, USA. */ |
| |
| /* All i80960 development is done in a CROSS-DEVELOPMENT environment. I.e., |
| object code is generated on, and executed under the direction of a symbolic |
| debugger running on, a host system. We do not want to be subject to the |
| vagaries of which host it is or whether it supports COFF or a.out format, |
| or anything else. We DO want to: |
| |
| o always generate the same format object files, regardless of host. |
| |
| o have an 'a.out' header that we can modify for our own purposes |
| (the 80960 is typically an embedded processor and may require |
| enhanced linker support that the normal a.out.h header can't |
| accommodate). |
| |
| As for byte-ordering, the following rules apply: |
| |
| o Text and data that is actually downloaded to the target is always |
| in i80960 (little-endian) order. |
| |
| o All other numbers (in the header, symbols, relocation directives) |
| are in host byte-order: object files CANNOT be lifted from a |
| little-end host and used on a big-endian (or vice versa) without |
| modification. |
| ==> THIS IS NO LONGER TRUE USING BFD. WE CAN GENERATE ANY BYTE ORDER |
| FOR THE HEADER, AND READ ANY BYTE ORDER. PREFERENCE WOULD BE TO |
| USE LITTLE-ENDIAN BYTE ORDER THROUGHOUT, REGARDLESS OF HOST. <== |
| |
| o The downloader ('comm960') takes care to generate a pseudo-header |
| with correct (i80960) byte-ordering before shipping text and data |
| off to the NINDY monitor in the target systems. Symbols and |
| relocation info are never sent to the target. */ |
| |
| #define BMAGIC 0415 |
| /* We don't accept the following (see N_BADMAG macro). |
| They're just here so GNU code will compile. */ |
| #define OMAGIC 0407 /* old impure format */ |
| #define NMAGIC 0410 /* read-only text */ |
| #define ZMAGIC 0413 /* demand load format */ |
| |
| /* FILE HEADER |
| All 'lengths' are given as a number of bytes. |
| All 'alignments' are for relinkable files only; an alignment of |
| 'n' indicates the corresponding segment must begin at an |
| address that is a multiple of (2**n). */ |
| struct external_exec |
| { |
| /* Standard stuff */ |
| unsigned char e_info[4]; /* Identifies this as a b.out file */ |
| unsigned char e_text[4]; /* Length of text */ |
| unsigned char e_data[4]; /* Length of data */ |
| unsigned char e_bss[4]; /* Length of uninitialized data area */ |
| unsigned char e_syms[4]; /* Length of symbol table */ |
| unsigned char e_entry[4]; /* Runtime start address */ |
| unsigned char e_trsize[4]; /* Length of text relocation info */ |
| unsigned char e_drsize[4]; /* Length of data relocation info */ |
| |
| /* Added for i960 */ |
| unsigned char e_tload[4]; /* Text runtime load address */ |
| unsigned char e_dload[4]; /* Data runtime load address */ |
| unsigned char e_talign[1]; /* Alignment of text segment */ |
| unsigned char e_dalign[1]; /* Alignment of data segment */ |
| unsigned char e_balign[1]; /* Alignment of bss segment */ |
| unsigned char e_relaxable[1];/* Assembled with enough info to allow linker to relax */ |
| }; |
| |
| #define EXEC_BYTES_SIZE (sizeof (struct external_exec)) |
| |
| /* These macros use the a_xxx field names, since they operate on the exec |
| structure after it's been byte-swapped and realigned on the host machine. */ |
| #define N_BADMAG(x) (((x)->a_info)!=BMAGIC) |
| #define N_TXTOFF(x) EXEC_BYTES_SIZE |
| #define N_DATOFF(x) ( N_TXTOFF(x) + (x)->a_text ) |
| #define N_TROFF(x) ( N_DATOFF(x) + (x)->a_data ) |
| #define N_TRELOFF N_TROFF |
| #define N_DROFF(x) ( N_TROFF(x) + (x)->a_trsize ) |
| #define N_DRELOFF N_DROFF |
| #define N_SYMOFF(x) ( N_DROFF(x) + (x)->a_drsize ) |
| #define N_STROFF(x) ( N_SYMOFF(x) + (x)->a_syms ) |
| #define N_DATADDR(x) ( (x)->a_dload ) |
| |
| /* Address of text segment in memory after it is loaded. */ |
| #if !defined (N_TXTADDR) |
| #define N_TXTADDR(x) 0 |
| #endif |
| |
| /* A single entry in the symbol table. */ |
| struct nlist |
| { |
| union |
| { |
| char* n_name; |
| struct nlist * n_next; |
| long n_strx; /* Index into string table */ |
| } n_un; |
| |
| unsigned char n_type; /* See below */ |
| char n_other; /* Used in i80960 support -- see below */ |
| short n_desc; |
| unsigned long n_value; |
| }; |
| |
| |
| /* Legal values of n_type. */ |
| #define N_UNDF 0 /* Undefined symbol */ |
| #define N_ABS 2 /* Absolute symbol */ |
| #define N_TEXT 4 /* Text symbol */ |
| #define N_DATA 6 /* Data symbol */ |
| #define N_BSS 8 /* BSS symbol */ |
| #define N_FN 31 /* Filename symbol */ |
| |
| #define N_EXT 1 /* External symbol (OR'd in with one of above) */ |
| #define N_TYPE 036 /* Mask for all the type bits */ |
| #define N_STAB 0340 /* Mask for all bits used for SDB entries */ |
| |
| /* MEANING OF 'n_other' |
| |
| If non-zero, the 'n_other' fields indicates either a leaf procedure or |
| a system procedure, as follows: |
| |
| 1 <= n_other <= 32 : |
| The symbol is the entry point to a system procedure. |
| 'n_value' is the address of the entry, as for any other |
| procedure. The system procedure number (which can be used in |
| a 'calls' instruction) is (n_other-1). These entries come from |
| '.sysproc' directives. |
| |
| n_other == N_CALLNAME |
| the symbol is the 'call' entry point to a leaf procedure. |
| The *next* symbol in the symbol table must be the corresponding |
| 'bal' entry point to the procedure (see following). These |
| entries come from '.leafproc' directives in which two different |
| symbols are specified (the first one is represented here). |
| |
| |
| n_other == N_BALNAME |
| the symbol is the 'bal' entry point to a leaf procedure. |
| These entries result from '.leafproc' directives in which only |
| one symbol is specified, or in which the same symbol is |
| specified twice. |
| |
| Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry, |
| but not every N_BALNAME entry must have an N_CALLNAME entry. */ |
| #define N_CALLNAME ((char)-1) |
| #define N_BALNAME ((char)-2) |
| #define IS_CALLNAME(x) (N_CALLNAME == (x)) |
| #define IS_BALNAME(x) (N_BALNAME == (x)) |
| #define IS_OTHER(x) ((x)>0 && (x) <=32) |
| |
| #define b_out_relocation_info relocation_info |
| struct relocation_info |
| { |
| int r_address; /* File address of item to be relocated. */ |
| unsigned |
| #define r_index r_symbolnum |
| r_symbolnum:24, /* Index of symbol on which relocation is based, |
| if r_extern is set. Otherwise set to |
| either N_TEXT, N_DATA, or N_BSS to |
| indicate section on which relocation is |
| based. */ |
| r_pcrel:1, /* 1 => relocate PC-relative; else absolute |
| On i960, pc-relative implies 24-bit |
| address, absolute implies 32-bit. */ |
| r_length:2, /* Number of bytes to relocate: |
| 0 => 1 byte |
| 1 => 2 bytes -- used for 13 bit pcrel |
| 2 => 4 bytes. */ |
| r_extern:1, |
| r_bsr:1, /* Something for the GNU NS32K assembler. */ |
| r_disp:1, /* Something for the GNU NS32K assembler. */ |
| r_callj:1, /* 1 if relocation target is an i960 'callj'. */ |
| r_relaxable:1; /* 1 if enough info is left to relax the data. */ |
| }; |