Xinu7/include/a.out.h

/* a.out.h */

struct	exec {	/* a.out header */
	short		a_magic;	/* magic number			*/
	unsigned short	a_text;		/* size of text segment		*/
	unsigned short	a_data;		/* size of initialized data	*/
	unsigned short	a_bss;		/* size of uninitialized data	*/
	unsigned short	a_syms;		/* size of symbol table		*/
	unsigned short	a_entry;	/* entry point			*/
	unsigned short	a_unused;	/* not used			*/
	char		a_flag;		/* relocation info stripped	*/
	char		a_v6;		/* UNIX V6 compatibility  mode	*/
};

#define	A_MAGIC1	0407       	/* normal			*/
#define	A_MAGIC2	0410       	/* read-only text		*/
#define	A_MAGIC3	0411       	/* separated I&D		*/
#define	A_MAGIC4	0405       	/* overlay			*/

struct	nlist {				/* symbol table entry		*/
	char		n_name[8];	/* symbol name			*/
	short		n_type;		/* type flag			*/
	unsigned short	n_value;	/* value			*/
};

/* values for type flag */

#define	N_UNDF		0		/* undefined			*/
#define	N_ABS		01		/* absolute			*/
#define	N_TEXT		02		/* text symbol			*/
#define	N_DATA		03		/* data symbol			*/
#define	N_BSS		04		/* bss symbol			*/
#define	N_TYPE		037
#define	N_REG		024		/* register name		*/
#define	N_FN		037		/* file name symbol		*/
#define	N_EXT		040		/* external bit, or'ed in	*/
#define	FORMAT		"%06o"		/* to print a value		*/