reloc(4)                                                 reloc(4)



     NAME
          reloc - relocation information for a common object file

     SYNOPSIS
          #include  <reloc.h>

     DESCRIPTION
          Object files have one relocation entry for each relocatable
          reference in the text or data.  If relocation information is
          present, it will be in the following format.

          struct     reloc
          {
            long     r_vaddr ;   /* (virtual) address of reference */
            long     r_symndx ;  /* index into symbol table */
            short    r_type ;    /* relocation type */
          } ;


          /*
           * All generics
           *       reloc. already performed to symbol in the same section
           */
          #define  R_ABS                 0

          /*
           * DEC Processors  VAX 11/780 and VAX 11/750
           *
           */
          #define R_RELBYTE  017
          #define R_RELWORD  020
          #define R_RELLONG  021
          #define R_PCRBYTE  022
          #define R_PCRWORD  023
          #define R_PCRLONG  024

          /*
           * Motorola 68000 uses R_RELBYTE, R_RELWORD, R_RELLONG,
           * R_PCRBYTE, and R_PCRWORD as for DEC machines above.
           */


          As the link editor reads each input section and performs
          relocation, the relocation entries are read. They direct how
          references found within the input section are treated.

          RABS          The reference is absolute, and no relocation
                         is necessary.  The entry will be ignored.

          RRELBYTE      A direct 8-bit reference to a symbol's
                         virtual address.




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     reloc(4)                                                 reloc(4)



          RRELWORD      A direct 16-bit reference to a symbol's
                         virtual address.

          RRELLONG      A direct 32-bit reference to a symbol's
                         virtual address.

          RPCRBYTE      A ``PC-relative'' 8-bit reference to a
                         symbol's virtual address.

          RPCRWORD      A ``PC-relative'' 16-bit reference to a
                         symbol's virtual address.

          RPCRLONG      A ``PC-relative'' 32-bit reference to a
                         symbol's virtual address.

          On the VAX processors, relocation of a symbol index of -1
          indicates that the relative difference between the current
          segment's start address and the program's load address is
          added to the relocatable address.

          Other relocation types will be defined as they are needed.

          Relocation entries are generated automatically by the
          assembler and automatically utilized by the link editor. A
          link editor option exists for removing the relocation
          entries from an object file.

     SEE ALSO
          ld(1), strip(1), a.out(4), syms(4).


























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