[binutils.git] / include / bout.h

/*
 * 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).
 *
 * 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 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)
#define IS_CALLNAME(x)	(N_CALLNAME == (int)(x))
#define IS_BALNAME(x)	(N_BALNAME == (int)(x))
#define IS_OTHER(x)	((x)>0 && (x) <=32)

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,
				*	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
				 *	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				*/
};
Commit	Line	Data
9c6a9c92	1	/*
a07cc613 JG	2	* This file is a modified version of 'a.out.h'. It is to be used in all
	3	* GNU tools modified to support the i80960 (or tools that operate on
	4	* object files created by such tools).
	5	*
	6	* All i80960 development is done in a CROSS-DEVELOPMENT environment. I.e.,
	7	* object code is generated on, and executed under the direction of a symbolic
	8	* debugger running on, a host system. We do not want to be subject to the
	9	* vagaries of which host it is or whether it supports COFF or a.out format,
	10	* or anything else. We DO want to:
	11	*
	12	* o always generate the same format object files, regardless of host.
	13	*
	14	* o have an 'a.out' header that we can modify for our own purposes
	15	* (the 80960 is typically an embedded processor and may require
	16	* enhanced linker support that the normal a.out.h header can't
	17	* accommodate).
	18	*
	19	* As for byte-ordering, the following rules apply:
	20	*
	21	* o Text and data that is actually downloaded to the target is always
	22	* in i80960 (little-endian) order.
	23	*
	24	* o All other numbers (in the header, symbols, relocation directives)
	25	* are in host byte-order: object files CANNOT be lifted from a
	26	* little-end host and used on a big-endian (or vice versa) without
	27	* modification.
	28	* ==> THIS IS NO LONGER TRUE USING BFD. WE CAN GENERATE ANY BYTE ORDER
	29	* FOR THE HEADER, AND READ ANY BYTE ORDER. PREFERENCE WOULD BE TO
	30	* USE LITTLE-ENDIAN BYTE ORDER THROUGHOUT, REGARDLESS OF HOST. <==
	31	*
	32	* o The downloader ('comm960') takes care to generate a pseudo-header
	33	* with correct (i80960) byte-ordering before shipping text and data
	34	* off to the NINDY monitor in the target systems. Symbols and
	35	* relocation info are never sent to the target.
	36	*/
	37
	38
	39	#define BMAGIC 0415
	40	/* We don't accept the following (see N_BADMAG macro).
	41	* They're just here so GNU code will compile.
	42	*/
	43	#define OMAGIC 0407 /* old impure format */
	44	#define NMAGIC 0410 /* read-only text */
	45	#define ZMAGIC 0413 /* demand load format */
	46
	47	/* FILE HEADER
	48	* All 'lengths' are given as a number of bytes.
	49	* All 'alignments' are for relinkable files only; an alignment of
	50	* 'n' indicates the corresponding segment must begin at an
	51	* address that is a multiple of (2**n).
	52	*/
	53	struct exec {
	54	/* Standard stuff */
	55	unsigned long a_magic; /* Identifies this as a b.out file */
	56	unsigned long a_text; /* Length of text */
	57	unsigned long a_data; /* Length of data */
	58	unsigned long a_bss; /* Length of runtime uninitialized data area */
	59	unsigned long a_syms; /* Length of symbol table */
	60	unsigned long a_entry; /* Runtime start address */
	61	unsigned long a_trsize; /* Length of text relocation info */
	62	unsigned long a_drsize; /* Length of data relocation info */
	63
	64	/* Added for i960 */
	65	unsigned long a_tload; /* Text runtime load address */
66	unsigned long a_dload; /* Data runtime load address */
67	unsigned char a_talign; /* Alignment of text segment */
68	unsigned char a_dalign; /* Alignment of data segment */
69	unsigned char a_balign; /* Alignment of bss segment */
70	unsigned char unused; /* (Just to make struct size a multiple of 4) */
71	};
72
73	#define N_BADMAG(x) (((x).a_magic)!=BMAGIC)
74	#define N_TXTOFF(x) ( sizeof(struct exec) )
75	#define N_DATOFF(x) ( N_TXTOFF(x) + (x).a_text )
76	#define N_TROFF(x) ( N_DATOFF(x) + (x).a_data )
77	#define N_DROFF(x) ( N_TROFF(x) + (x).a_trsize )
78	#define N_SYMOFF(x) ( N_DROFF(x) + (x).a_drsize )
79	#define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms )
80
81	/* A single entry in the symbol table
82	*/
83	struct nlist {
84	union {
85	char *n_name;
86	struct nlist *n_next;
87	long n_strx; /* Index into string table */
88	} n_un;
89	unsigned char n_type; /* See below */
90	char n_other; /* Used in i80960 support -- see below */
91	short n_desc;
92	unsigned long n_value;
93	};
94
95
96	/* Legal values of n_type
97	*/
98	#define N_UNDF 0 /* Undefined symbol */
99	#define N_ABS 2 /* Absolute symbol */
100	#define N_TEXT 4 /* Text symbol */
101	#define N_DATA 6 /* Data symbol */
102	#define N_BSS 8 /* BSS symbol */
103	#define N_FN 31 /* Filename symbol */
104
105	#define N_EXT 1 /* External symbol (OR'd in with one of above) */
106	#define N_TYPE 036 /* Mask for all the type bits */
107	#define N_STAB 0340 /* Mask for all bits used for SDB entries */
108
109	/* MEANING OF 'n_other'
110	*
111	* If non-zero, the 'n_other' fields indicates either a leaf procedure or
112	* a system procedure, as follows:
113	*
114	* 1 <= n_other <= 32 :
115	* The symbol is the entry point to a system procedure.
116	* 'n_value' is the address of the entry, as for any other
117	* procedure. The system procedure number (which can be used in
118	* a 'calls' instruction) is (n_other-1). These entries come from
119	* '.sysproc' directives.
120	*
121	* n_other == N_CALLNAME
122	* the symbol is the 'call' entry point to a leaf procedure.
123	* The next symbol in the symbol table must be the corresponding
124	* 'bal' entry point to the procedure (see following). These
125	* entries come from '.leafproc' directives in which two different
126	* symbols are specified (the first one is represented here).
127	*
128	*
129	* n_other == N_BALNAME
130	* the symbol is the 'bal' entry point to a leaf procedure.
131	* These entries result from '.leafproc' directives in which only
132	* one symbol is specified, or in which the same symbol is
133	* specified twice.
134	*
135	* Note that an N_CALLNAME entry must have a corresponding N_BALNAME entry,
136	* but not every N_BALNAME entry must have an N_CALLNAME entry.
137	*/
138	#define N_CALLNAME (-1)
139	#define N_BALNAME (-2)
140	#define IS_CALLNAME(x) (N_CALLNAME == (int)(x))
141	#define IS_BALNAME(x) (N_BALNAME == (int)(x))
142	#define IS_OTHER(x) ((x)>0 && (x) <=32)
143
144	struct relocation_info {
145	int r_address; /* File address of item to be relocated */
146	unsigned
147	r_symbolnum:24,/* Index of symbol on which relocation is based,
148	* if r_extern is set. Otherwise set to
149	* either N_TEXT, N_DATA, or N_BSS to
150	* indicate section on which relocation is
151	* based.
152	*/
153	r_pcrel:1, /* 1 => relocate PC-relative; else absolute
154	* On i960, pc-relative implies 24-bit
155	* address, absolute implies 32-bit.
156	*/
157	r_length:2, /* Number of bytes to relocate:
158	* 0 => 1 byte
159	* 1 => 2 bytes
160	* 2 => 4 bytes -- only value used for i960
161	*/
162	r_extern:1,
163	r_bsr:1, /* Something for the GNU NS32K assembler */
164	r_disp:1, /* Something for the GNU NS32K assembler */
165	r_callj:1, /* 1 if relocation target is an i960 'callj' */
166	nuthin:1; /* Unused */
167	};