Minix1.5/include/a.out.h

/* The <a.out> header file describes the format of executable files. */

#ifndef _AOUT_H
#define _AOUT_H

struct	exec {			/* a.out header */
	unsigned char	a_magic[2];	/* magic number */
	unsigned char	a_flags;	/* flags, see below */
	unsigned char	a_cpu;		/* cpu id */
	unsigned char	a_hdrlen;	/* length of header */
	unsigned char	a_unused;	/* reserved for future use */
	unsigned short	a_version;	/* version stamp */	
				/* not used */
	long		a_text;		/* size of text segement in bytes */
	long		a_data;		/* size of data segment in bytes */
	long		a_bss;		/* size of bss segment in bytes */
	long		a_no_entry;	/* in fact: entry point, a_entry */
	long		a_total;	/* total memory allocated */
	long		a_syms;		/* size of symbol table */
				/* SHORT FORM ENDS HERE */
	long		a_trsize;	/* text relocation size */
	long		a_drsize;	/* data relocation size */
	long		a_tbase;	/* text relocation base */
	long		a_dbase;	/* data relocation base */
};

#define A_MAGIC0	(unsigned char) 0x01
#define A_MAGIC1	(unsigned char) 0x03
#define BADMAG(X)	((X).a_magic[0] != A_MAGIC0 ||\
			 (X).a_magic[1] != A_MAGIC1)

/* CPU Id of TARGET machine */
	/* byte order coded in low order two bits */
#define A_NONE	0x00	/* unknown */
#define A_I8086	0x04	/* intel i8086/8088 */
#define A_M68K	0x0B	/* motorola m68000 */
#define A_NS16K	0x0C	/* national semiconductor 16032 */
#define A_I80386	0x10	/* intel i80386 */

#define A_BLR(cputype)	((cputype&0x01)!=0) /* TRUE if bytes left-to-right */
#define A_WLR(cputype)	((cputype&0x02)!=0) /* TRUE if words left-to-right */

/* flags: */
#define A_EXEC	0x10	/* executable */
#define A_SEP	0x20	/* separate I/D */
#define A_PURE	0x40	/* pure text */		/* not used */
#define A_TOVLY	0x80	/* text overlay */	/* not used */

/* offsets of various things: */
#define A_MINHDR	32
#define	A_TEXTPOS(X)	((long)(X).a_hdrlen)
#define A_DATAPOS(X)	(A_TEXTPOS(X) + (X).a_text)
#define	A_HASRELS(X)	((X).a_hdrlen > (unsigned char) A_MINHDR)
#define A_HASEXT(X)	((X).a_hdrlen > (unsigned char) (A_MINHDR +  8))
#define A_HASLNS(X)	((X).a_hdrlen > (unsigned char) (A_MINHDR + 16))
#define A_HASTOFF(X)	((X).a_hdrlen > (unsigned char) (A_MINHDR + 24))
#define A_TRELPOS(X)	(A_DATAPOS(X) + (X).a_data)
#define A_DRELPOS(X)	(A_TRELPOS(X) + (X).a_trsize)
#define A_SYMPOS(X)	(A_TRELPOS(X) + (A_HASRELS(X) ? \
				((X).a_trsize + (X).a_drsize) : 0))

struct reloc {
	long		r_vaddr;	/* virtual address of reference */
	unsigned short	r_symndx;	/* internal segnum or extern symbol num */
	unsigned short	r_type;		/* relocation type */
};

/* r_tyep values: */
#define R_ABBS		0
#define R_RELLBYTE	2
#define R_PCRBYTE	3
#define R_RELWORD	4
#define R_PCRWORD	5
#define R_RELLONG	6
#define R_PCRLONG	7
#define R_REL3BYTE	8
#define R_KBRANCHE	9

/* r_symndx for internal segments */
#define S_ABS		((unsigned short)-1)
#define S_TEXT		((unsigned short)-2)
#define S_DATA		((unsigned short)-3)
#define S_BSS		((unsigned short)-4)

struct nlist {			/* symbol table entry */
	char	 	n_name[8];	/* symbol name */
	long	 	n_value;	/* value */
	unsigned char	n_sclass;	/* storage class */
	unsigned char	n_numaux;	/* number of auxiliary entries */
						/* not used */
	unsigned short	n_type;		/* language base and derived type */
						/* not used */
};

/* low bits of storage class (section) */
#define	N_SECT		  07	/* section mask */
#define N_UNDF		  00	/* undefined */
#define N_ABS		  01	/* absolute */
#define N_TEXT		  02	/* text */
#define N_DATA		  03	/* data */
#define	N_BSS		  04	/* bss */
#define N_COMM		  05	/* (common) */

/* high bits of storage class */
#define N_CLASS		0370	/* storage class mask */
#define C_NULL
#define C_EXT		0020	/* external symbol */
#define C_STAT		0030	/* static */

#endif /* _AOUT_H */