Shamusworld >> Repos - rmac/blob - object.c

   1 //
   2 // RMAC - Reboot's Macro Assembler for the Atari Jaguar Console System
   3 // OBJECT.C - Writing Object Files
   4 // Copyright (C) 199x Landon Dyer, 2011 Reboot and Friends
   5 // RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986
   6 // Source utilised with the kind permission of Landon Dyer
   7 //
   8
   9 #include "object.h"
  10 #include "sect.h"
  11 #include "symbol.h"
  12 #include "mark.h"
  13 #include "error.h"
  14 #include "riscasm.h"
  15
  16 LONG symsize = 0;                       // Size of BSD symbol table
  17 LONG strindx = 0x00000004;      // BSD string table index
  18 char * strtable;                        // Pointer to the symbol string table
  19 char * objImage;                        // Global object image pointer
  20
  21
  22 //
  23 // Add an entry to the BSD symbol table
  24 //
  25 char * constr_bsdsymtab(char * buf, SYM * sym, int globflag)
  26 {
  27         chptr = buf;                                            // Point to buffer for deposit longs
  28         D_long(strindx);                                        // Deposit the symbol string index
  29
  30         WORD w1 = sym->sattr;                           // Obtain symbol attribute
  31         int w2 = sym->sattre;
  32         LONG z = 0;                                                     // Initialise resulting symbol flags
  33
  34         if (w1 & EQUATED)
  35         {
  36                 z = 0x02000000;                                 // Set equated flag
  37         }
  38         else
  39         {
  40                 switch (w1 & TDB)
  41                 {
  42                 case TEXT: z = 0x04000000; break;       // Set TEXT segment flag
  43                 case DATA: z = 0x06000000; break;       // Set DATA segment flag
  44                 case BSS : z = 0x08000000; break;       // Set BSS segment flag
  45                 }
  46         }
  47
  48         if (globflag)
  49                 z |= 0x01000000;                                // Set global flag if requested
  50
  51         D_long(z);                                                      // Deposit symbol attribute
  52
  53         z = sym->svalue;                                        // Obtain symbol value
  54         w1 &= DATA | BSS;                                       // Determine DATA or BSS flag
  55
  56         if (w1)
  57                 z += sect[TEXT].sloc;                   // If DATA or BSS add TEXT segment size
  58
  59         if (w1 & BSS)
  60                 z += sect[DATA].sloc;                   // If BSS add DATA segment size
  61
  62         D_long(z);                                                      // Deposit symbol value
  63
  64         strcpy(strtable + strindx, sym->sname);
  65
  66         strindx += strlen(sym->sname) + 1;      // Incr string index incl null terminate
  67         buf += 12;                                                      // Increment buffer to next record
  68         symsize += 12;                                          // Increment symbol table size
  69
  70         return buf;
  71 }
  72
  73
  74 //
  75 // Write an object file to the passed in file descriptor
  76 // N.B.: Return value is ignored...
  77 //
  78 int WriteObject(int fd)
  79 {
  80         LONG t;                                 // Scratch long
  81         LONG tds;                               // TEXT & DATA segment size
  82         int i;                                  // Temporary int
  83         CHUNK * cp;                             // Chunk (for gather)
  84         char * buf;                             // Scratch area
  85         char * p;                               // Temporary ptr
  86         LONG ssize;                             // Size of symbols
  87         LONG trsize, drsize;    // Size of relocations
  88         long unused;                    // For supressing 'write' warnings
  89
  90         // Write requested object file...
  91         switch (obj_format)
  92         {
  93         case BSD:
  94                 ssize = ((LONG)sy_assign(NULL, NULL));          // Assign index numbers to the symbols
  95                 tds = sect[TEXT].sloc + sect[DATA].sloc;        // Get size of TEXT and DATA segment
  96                 buf = malloc(0x600000);                                         // Allocate 6mb object file image memory
  97
  98                 if (buf == NULL)
  99                 {
 100                         error("cannot allocate object file memory (in BSD mode)");
 101                         return ERROR;
 102                 }
 103
 104                 memset(buf, 0, 0x600000);               // Reset allocated memory
 105                 objImage = buf;                                 // Set global object image pointer
 106                 strtable = malloc(0x200000);    // Allocate 2mb scratch buffer
 107
 108                 if (strtable == NULL)
 109                 {
 110                         error("cannot allocate string table memory (in BSD mode)");
 111                         return ERROR;
 112                 }
 113
 114                 memset(strtable, 0, 0x200000);  // Reset allocated memory
 115
 116                 // Build object file header
 117                 chptr = buf;                                    // Base of header
 118                 D_long(0x00000107);                             // Magic number
 119                 D_long(sect[TEXT].sloc);                // TEXT size
 120                 D_long(sect[DATA].sloc);                // DATA size
 121                 D_long(sect[BSS].sloc);                 // BSS size
 122                 D_long(0x00000000);                             // Symbol size
 123                 D_long(0x00000000);                             // First entry (0L)
 124                 D_long(0x00000000);                             // TEXT relocation size
 125                 D_long(0x00000000);                             // BSD relocation size
 126
 127                 // Construct TEXT and DATA segments (without relocation changes)
 128                 p = buf + BSDHDRSIZE;
 129
 130                 for(i=TEXT; i<=DATA; ++i)
 131                 {
 132                         for(cp=sect[i].sfcode; cp!=NULL; cp=cp->chnext)
 133                         {
 134                                 memcpy(p, cp->chptr, cp->ch_size);
 135                                 p += cp->ch_size;
 136                         }
 137                 }
 138
 139                 // Do relocation tables (and make changes to segment data)
 140                 p = buf + (BSDHDRSIZE + tds);   // Move obj image ptr to reloc info
 141                 trsize = bsdmarkimg(p, tds, sect[TEXT].sloc, TEXT);// Do TEXT relocation table
 142                 chptr = buf + 24;                               // Point to relocation hdr entry
 143                 D_long(trsize);                                 // Write the relocation table size
 144                 p = buf + (BSDHDRSIZE + tds + trsize);  // Move obj image ptr to reloc info
 145                 drsize = bsdmarkimg(p, tds, sect[TEXT].sloc, DATA);// Do DATA relocation table
 146                 chptr = buf + 28;                               // Point to relocation hdr entry
 147                 D_long(drsize);                                 // Write the relocation table size
 148
 149                 p = buf + (BSDHDRSIZE + tds + trsize + drsize);// Point to start of symbol table
 150                 sy_assign(p, constr_bsdsymtab); // Build symbol and string tables
 151                 chptr = buf + 16;                               // Point to sym table size hdr entry
 152                 D_long(symsize);                                // Write the symbol table size
 153
 154                 // Point to string table
 155                 p = buf + (BSDHDRSIZE + tds + trsize + drsize + symsize);
 156
 157                 memcpy(p, strtable, strindx);   // Copy string table to object image
 158
 159                 if (buf)
 160                         free(strtable);                         // Free allocated memory
 161
 162                 chptr = p;                                              // Point to string table size long
 163                 D_long(strindx);                                // Write string table size
 164
 165                 // Write the BSD object file from the object image buffer
 166                 unused = write(fd, buf, BSDHDRSIZE + tds + trsize + drsize + symsize + strindx + 4);
 167
 168                 if (buf)
 169                         free(buf);                                      // Free allocated memory
 170
 171                 break;
 172         }
 173
 174         return 0;
 175 }
 176