rdoff/rdoff.h

   1 /*
   2  * rdoff.h      RDOFF Object File manipulation routines header file
   3  *
   4  * The Netwide Assembler is copyright (C) 1996 Simon Tatham and
   5  * Julian Hall. All rights reserved. The software is
   6  * redistributable under the licence given in the file "Licence"
   7  * distributed in the NASM archive.
   8  *
   9  * Permission to use this file in your own projects is granted, as int32_t
  10  * as acknowledgement is given in an appropriate manner to its authors,
  11  * with instructions of how to obtain a copy via ftp.
  12  */
  13
  14 #ifndef RDOFF_RDOFF_H
  15 #define RDOFF_RDOFF_H 1
  16
  17 #include <inttypes.h>
  18
  19 /*
  20  * RDOFF definitions. They are used by RDOFF utilities and by NASM's
  21  * 'outrdf2.c' output module.
  22  */
  23
  24 /* RDOFF format revision (currently used only when printing the version) */
  25 #define RDOFF2_REVISION         "0.6.1"
  26
  27 /* RDOFF2 file signature */
  28 #define RDOFF2_SIGNATURE        "RDOFF2"
  29
  30 /* Maximum size of an import/export label (including trailing zero) */
  31 #define EXIM_LABEL_MAX          64
  32
  33 /* Maximum size of library or module name (including trailing zero) */
  34 #define MODLIB_NAME_MAX         128
  35
  36 /* Maximum number of segments that we can handle in one file */
  37 #define RDF_MAXSEGS             64
  38
  39 /* Record types that may present the RDOFF header */
  40 #define RDFREC_GENERIC          0
  41 #define RDFREC_RELOC            1
  42 #define RDFREC_IMPORT           2
  43 #define RDFREC_GLOBAL           3
  44 #define RDFREC_DLL              4
  45 #define RDFREC_BSS              5
  46 #define RDFREC_SEGRELOC         6
  47 #define RDFREC_FARIMPORT        7
  48 #define RDFREC_MODNAME          8
  49 #define RDFREC_COMMON           10
  50
  51 /*
  52  * Generic record - contains the type and length field, plus a 128 byte
  53  * array 'data'
  54  */
  55 struct GenericRec {
  56     uint8_t type;
  57     uint8_t reclen;
  58     char data[128];
  59 };
  60
  61 /*
  62  * Relocation record
  63  */
  64 struct RelocRec {
  65     uint8_t type;                  /* must be 1 */
  66     uint8_t reclen;                /* content length */
  67     uint8_t segment;               /* only 0 for code, or 1 for data supported,
  68                                    but add 64 for relative refs (ie do not require
  69                                    reloc @ loadtime, only linkage) */
  70     int32_t offset;                /* from start of segment in which reference is loc'd */
  71     uint8_t length;                /* 1 2 or 4 bytes */
  72     uint16_t refseg;              /* segment to which reference refers to */
  73 };
  74
  75 /*
  76  * Extern/import record
  77  */
  78 struct ImportRec {
  79     uint8_t type;                  /* must be 2 */
  80     uint8_t reclen;                /* content length */
  81     uint8_t flags;                 /* SYM_* flags (see below) */
  82     uint16_t segment;             /* segment number allocated to the label for reloc
  83                                    records - label is assumed to be at offset zero
  84                                    in this segment, so linker must fix up with offset
  85                                    of segment and of offset within segment */
  86     char label[EXIM_LABEL_MAX]; /* zero terminated, should be written to file
  87                                    until the zero, but not after it */
  88 };
  89
  90 /*
  91  * Public/export record
  92  */
  93 struct ExportRec {
  94     uint8_t type;                  /* must be 3 */
  95     uint8_t reclen;                /* content length */
  96     uint8_t flags;                 /* SYM_* flags (see below) */
  97     uint8_t segment;               /* segment referred to (0/1/2) */
  98     int32_t offset;                /* offset within segment */
  99     char label[EXIM_LABEL_MAX]; /* zero terminated as in import */
 100 };
 101
 102 /*
 103  * DLL record
 104  */
 105 struct DLLRec {
 106     uint8_t type;                  /* must be 4 */
 107     uint8_t reclen;                /* content length */
 108     char libname[MODLIB_NAME_MAX];      /* name of library to link with at load time */
 109 };
 110
 111 /*
 112  * BSS record
 113  */
 114 struct BSSRec {
 115     uint8_t type;                  /* must be 5 */
 116     uint8_t reclen;                /* content length */
 117     int32_t amount;                /* number of bytes BSS to reserve */
 118 };
 119
 120 /*
 121  * Module name record
 122  */
 123 struct ModRec {
 124     uint8_t type;                  /* must be 8 */
 125     uint8_t reclen;                /* content length */
 126     char modname[MODLIB_NAME_MAX];      /* module name */
 127 };
 128
 129 /*
 130  * Common variable record
 131  */
 132 struct CommonRec {
 133     uint8_t type;                  /* must be 10 */
 134     uint8_t reclen;                /* equals 7+label length */
 135     uint16_t segment;             /* segment number */
 136     int32_t size;                  /* size of common variable */
 137     uint16_t align;               /* alignment (power of two) */
 138     char label[EXIM_LABEL_MAX]; /* zero terminated as in import */
 139 };
 140
 141 /* Flags for ExportRec */
 142 #define SYM_DATA        1
 143 #define SYM_FUNCTION    2
 144 #define SYM_GLOBAL      4
 145 #define SYM_IMPORT      8
 146
 147 /*** The following part is used only by the utilities *************************/
 148
 149 #ifdef RDOFF_UTILS
 150
 151 /* Some systems don't define this automatically */
 152 #if !defined(strdup)
 153 extern char *strdup(const char *);
 154 #endif
 155
 156 typedef union RDFHeaderRec {
 157     char type;                  /* invariant throughout all below */
 158     struct GenericRec g;        /* type 0 */
 159     struct RelocRec r;          /* type == 1 / 6 */
 160     struct ImportRec i;         /* type == 2 / 7 */
 161     struct ExportRec e;         /* type == 3 */
 162     struct DLLRec d;            /* type == 4 */
 163     struct BSSRec b;            /* type == 5 */
 164     struct ModRec m;            /* type == 8 */
 165     struct CommonRec c;         /* type == 10 */
 166 } rdfheaderrec;
 167
 168 struct SegmentHeaderRec {
 169     /* information from file */
 170     uint16_t type;
 171     uint16_t number;
 172     uint16_t reserved;
 173     int32_t length;
 174
 175     /* information built up here */
 176     int32_t offset;
 177     uint8_t *data;                 /* pointer to segment data if it exists in memory */
 178 };
 179
 180 typedef struct RDFFileInfo {
 181     FILE *fp;                   /* file descriptor; must be open to use this struct */
 182     int rdoff_ver;              /* should be 1; any higher => not guaranteed to work */
 183     int32_t header_len;
 184     int32_t header_ofs;
 185
 186     uint8_t *header_loc;           /* keep location of header */
 187     int32_t header_fp;             /* current location within header for reading */
 188
 189     struct SegmentHeaderRec seg[RDF_MAXSEGS];
 190     int nsegs;
 191
 192     int32_t eof_offset;            /* offset of the first uint8_t beyond the end of this
 193                                    module */
 194
 195     char *name;                 /* name of module in libraries */
 196     int *refcount;              /* pointer to reference count on file, or NULL */
 197 } rdffile;
 198
 199 #define BUF_BLOCK_LEN 4088      /* selected to match page size (4096)
 200                                  * on 80x86 machines for efficiency */
 201 typedef struct memorybuffer {
 202     int length;
 203     uint8_t buffer[BUF_BLOCK_LEN];
 204     struct memorybuffer *next;
 205 } memorybuffer;
 206
 207 typedef struct {
 208     memorybuffer *buf;          /* buffer containing header records */
 209     int nsegments;              /* number of segments to be written */
 210     int32_t seglength;             /* total length of all the segments */
 211 } rdf_headerbuf;
 212
 213 /* segments used by RDOFF, understood by rdoffloadseg */
 214 #define RDOFF_CODE      0
 215 #define RDOFF_DATA      1
 216 #define RDOFF_HEADER    -1
 217 /* mask for 'segment' in relocation records to find if relative relocation */
 218 #define RDOFF_RELATIVEMASK 64
 219 /* mask to find actual segment value in relocation records */
 220 #define RDOFF_SEGMENTMASK 63
 221
 222 extern int rdf_errno;
 223
 224 /* rdf_errno can hold these error codes */
 225 enum {
 226     /* 0 */ RDF_OK,
 227     /* 1 */ RDF_ERR_OPEN,
 228     /* 2 */ RDF_ERR_FORMAT,
 229     /* 3 */ RDF_ERR_READ,
 230     /* 4 */ RDF_ERR_UNKNOWN,
 231     /* 5 */ RDF_ERR_HEADER,
 232     /* 6 */ RDF_ERR_NOMEM,
 233     /* 7 */ RDF_ERR_VER,
 234     /* 8 */ RDF_ERR_RECTYPE,
 235     /* 9 */ RDF_ERR_RECLEN,
 236     /* 10 */ RDF_ERR_SEGMENT
 237 };
 238
 239 /* utility functions */
 240 int32_t translateint32_t(int32_t in);
 241 uint16_t translateint16_t(uint16_t in);
 242 char *translatesegmenttype(uint16_t type);
 243
 244 /* RDOFF file manipulation functions */
 245 int rdfopen(rdffile * f, const char *name);
 246 int rdfopenhere(rdffile * f, FILE * fp, int *refcount, const char *name);
 247 int rdfclose(rdffile * f);
 248 int rdffindsegment(rdffile * f, int segno);
 249 int rdfloadseg(rdffile * f, int segment, void *buffer);
 250 rdfheaderrec *rdfgetheaderrec(rdffile * f);     /* returns static storage */
 251 void rdfheaderrewind(rdffile * f);      /* back to start of header */
 252 void rdfperror(const char *app, const char *name);
 253
 254 /* functions to write a new RDOFF header to a file -
 255    use rdfnewheader to allocate a header, rdfaddheader to add records to it,
 256    rdfaddsegment to notify the header routines that a segment exists, and
 257    to tell it how int32_t the segment will be.
 258    rdfwriteheader to write the file id, object length, and header
 259    to a file, and then rdfdoneheader to dispose of the header */
 260
 261 rdf_headerbuf *rdfnewheader(void);
 262 int rdfaddheader(rdf_headerbuf * h, rdfheaderrec * r);
 263 int rdfaddsegment(rdf_headerbuf * h, int32_t seglength);
 264 int rdfwriteheader(FILE * fp, rdf_headerbuf * h);
 265 void rdfdoneheader(rdf_headerbuf * h);
 266
 267 #endif                          /* RDOFF_UTILS */
 268
 269 #endif                          /* RDOFF_RDOFF_H */