/* Copyright 1992 Free Software Foundation, Inc. * * This file is a modified version of 'a.out.h'. It is to be used in all * all GNU tools modified to support the i80960 (or tools that operate on * object files created by such tools). * * 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. * * 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 exec { /* Standard stuff */ unsigned long a_magic; /* Identifies this as a b.out file */ unsigned long a_text; /* Length of text */ unsigned long a_data; /* Length of data */ unsigned long a_bss; /* Length of runtime uninitialized data area */ unsigned long a_syms; /* Length of symbol table */ unsigned long a_entry; /* Runtime start address */ unsigned long a_trsize; /* Length of text relocation info */ unsigned long a_drsize; /* Length of data relocation info */ /* Added for i960 */ unsigned long a_tload; /* Text runtime load address */ unsigned long a_dload; /* Data runtime load address */ unsigned char a_talign; /* Alignment of text segment */ unsigned char a_dalign; /* Alignment of data segment */ unsigned char a_balign; /* Alignment of bss segment */ unsigned char unused; /* (Just to make struct size a multiple of 4) */ }; #define N_BADMAG(x) (((x).a_magic)!=BMAGIC) #define N_TXTOFF(x) ( sizeof(struct exec) ) #define N_DATOFF(x) ( N_TXTOFF(x) + (x).a_text ) #define N_TROFF(x) ( N_DATOFF(x) + (x).a_data ) #define N_DROFF(x) ( N_TROFF(x) + (x).a_trsize ) #define N_SYMOFF(x) ( N_DROFF(x) + (x).a_drsize ) #define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms ) /* 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 -1 #define N_BALNAME -2 struct relocation_info { int r_address; /* File address of item to be relocated */ unsigned r_symbolnum:24,/* Index of symbol 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 * 2 => 4 bytes -- only value used for i960 */ 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' */ nuthin:1; /* Unused */ };