a.out.h

一个简单的操作系统minix的核心代码

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				include/a.out.h	 	 
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01400	/* The <a.out> header file describes the format of executable files. */
01401	
01402	#ifndef _AOUT_H
01403	#define _AOUT_H
01404	
01405	struct  exec {                  /* a.out header */
01406	  unsigned char a_magic[2];     /* magic number */
01407	  unsigned char a_flags;        /* flags, see below */
01408	  unsigned char a_cpu;          /* cpu id */
01409	  unsigned char a_hdrlen;       /* length of header */
01410	  unsigned char a_unused;       /* reserved for future use */
01411	  unsigned short a_version;     /* version stamp (not used at present) */
01412	  long          a_text;         /* size of text segement in bytes */
01413	  long          a_data;         /* size of data segment in bytes */
01414	  long          a_bss;          /* size of bss segment in bytes */
01415	  long          a_entry;        /* entry point */
01416	  long          a_total;        /* total memory allocated */
01417	  long          a_syms;         /* size of symbol table */
01418	
01419	  /* SHORT FORM ENDS HERE */
01420	  long          a_trsize;       /* text relocation size */
01421	  long          a_drsize;       /* data relocation size */
01422	  long          a_tbase;        /* text relocation base */
01423	  long          a_dbase;        /* data relocation base */
01424	};
01425	
01426	#define A_MAGIC0      (unsigned char) 0x01
01427	#define A_MAGIC1      (unsigned char) 0x03
01428	#define BADMAG(X)     ((X).a_magic[0] != A_MAGIC0 ||(X).a_magic[1] != A_MAGIC1)
01429	
01430	/* CPU Id of TARGET machine (byte order coded in low order two bits) */
01431	#define A_NONE  0x00    /* unknown */
01432	#define A_I8086 0x04    /* intel i8086/8088 */
01433	#define A_M68K  0x0B    /* motorola m68000 */
01434	#define A_NS16K 0x0C    /* national semiconductor 16032 */
01435	#define A_I80386 0x10   /* intel i80386 */
01436	#define A_SPARC 0x17    /* Sun SPARC */
01437	
01438	#define A_BLR(cputype)  ((cputype&0x01)!=0) /* TRUE if bytes left-to-right */
01439	#define A_WLR(cputype)  ((cputype&0x02)!=0) /* TRUE if words left-to-right */
01440	
01441	/* Flags. */
01442	#define A_UZP   0x01    /* unmapped zero page (pages) */
01443	#define A_PAL   0x02    /* page aligned executable */
01444	#define A_NSYM  0x04    /* new style symbol table */
01445	#define A_EXEC  0x10    /* executable */
01446	#define A_SEP   0x20    /* separate I/D */
01447	#define A_PURE  0x40    /* pure text */         /* not used */
01448	#define A_TOVLY 0x80    /* text overlay */      /* not used */
01449	
01450	/* Offsets of various things. */
01451	#define A_MINHDR        32
01452	#define A_TEXTPOS(X)    ((long)(X).a_hdrlen)
01453	#define A_DATAPOS(X)    (A_TEXTPOS(X) + (X).a_text)
01454	#define A_HASRELS(X)    ((X).a_hdrlen > (unsigned char) A_MINHDR)
01455	#define A_HASEXT(X)     ((X).a_hdrlen > (unsigned char) (A_MINHDR +  8))
01456	#define A_HASLNS(X)     ((X).a_hdrlen > (unsigned char) (A_MINHDR + 16))
01457	#define A_HASTOFF(X)    ((X).a_hdrlen > (unsigned char) (A_MINHDR + 24))
01458	#define A_TRELPOS(X)    (A_DATAPOS(X) + (X).a_data)
01459	#define A_DRELPOS(X)    (A_TRELPOS(X) + (X).a_trsize)
01460	#define A_SYMPOS(X)     (A_TRELPOS(X) + (A_HASRELS(X) ? \
01461	                        ((X).a_trsize + (X).a_drsize) : 0))
01462	
01463	struct reloc {
01464	  long r_vaddr;                 /* virtual address of reference */
01465	  unsigned short r_symndx;      /* internal segnum or extern symbol num */
01466	  unsigned short r_type;        /* relocation type */
01467	};
01468	
01469	/* r_tyep values: */
01470	#define R_ABBS          0
01471	#define R_RELLBYTE      2
01472	#define R_PCRBYTE       3
01473	#define R_RELWORD       4
01474	#define R_PCRWORD       5
01475	#define R_RELLONG       6
01476	#define R_PCRLONG       7
01477	#define R_REL3BYTE      8
01478	#define R_KBRANCHE      9
01479	
01480	/* r_symndx for internal segments */
01481	#define S_ABS           ((unsigned short)-1)
01482	#define S_TEXT          ((unsigned short)-2)
01483	#define S_DATA          ((unsigned short)-3)
01484	#define S_BSS           ((unsigned short)-4)
01485	
01486	struct nlist {                  /* symbol table entry */
01487	  char n_name[8];               /* symbol name */
01488	  long n_value;                 /* value */
01489	  unsigned char n_sclass;       /* storage class */
01490	  unsigned char n_numaux;       /* number of auxiliary entries (not used) */
01491	  unsigned short n_type;        /* language base and derived type (not used) */
01492	};
01493	
01494	/* Low bits of storage class (section). */
01495	#define N_SECT            07    /* section mask */
01496	#define N_UNDF            00    /* undefined */
01497	#define N_ABS             01    /* absolute */
01498	#define N_TEXT            02    /* text */
01499	#define N_DATA            03    /* data */
01500	#define N_BSS             04    /* bss */
01501	#define N_COMM            05    /* (common) */
01502	
01503	/* High bits of storage class. */
01504	#define N_CLASS         0370    /* storage class mask */
01505	#define C_NULL
01506	#define C_EXT           0020    /* external symbol */
01507	#define C_STAT          0030    /* static */
01508	
01509	/* Function prototypes. */
01510	#ifndef _ANSI_H
01511	#include <ansi.h>
01512	#endif
01513	
01514	_PROTOTYPE( int nlist, (char *_file, struct nlist *_nl)                 );
01515	
01516	#endif /* _AOUT_H */