ld86

ld86(1)                                                                ld86(1)



NAME
       ld86 - Linker for as86(1)

SYNOPSIS
       ld86   [-03MNdimrstyz[-]]  [-llib_extension]  [-o outfile]  [-Ccrtfile]
       [-Llibdir] [-Olibfile] [-Ttextaddr] [-Hheapsize] [-Ddataaddr] infile...


DESCRIPTION
       This  linker  understands  only  the  object files produced by the as86
       assembler, it can link them into either an impure  or  a  separate  I&D
       executable.

       The  linking  defaults are everything off or none except for -0 and the
       output file is a.out.  There is not a standard library location defined
       in the linker.


OPTIONS
       -0     produce header with 16-bit magic

       -3     produce header with 32-bit magic

       -d     delete  the  header  from  the  output  file, used for MSDOS COM
              files. As a side effect this also includes -s as there's nowhere
              to put a symbol table.

       -Cx    add file libdir-from-search/crtx.o to list of files linked

       -D     data base address follows (in format suitable for strtoul)

       -H     the  top of heap (initial stack) address (in format suitable for
              strtoul)

       -Lx    add dir name x to the head of the list of library dirs searched

       -M     print symbols linked on stdout

       -N     Create a native Linux OMAGIC output file. If  the  contents  are
              i386  code the binary can be either linked by GCC or executed by
              linux. If the -z option is also included the linker can generate
              a QMAGIC executable.

       -Ox    add library or object file libdir-from-search/x to list of files
              linked

       -T     text base address follows (in format suitable for strtoul)

       -i     separate I&D output

       -lx    add library libdir-from-search/libx.a to list of files linked

       -m     print modules linked on stdout

       -o     output file name follows

       -s     strip symbols

       -r     Generate a relocatable object from one  source  object,  if  the
              linker is given the -N option also the output format will be the
              hosts native format if possible.

       -t     trace modules being looked at on stdout

       -y     Alter the symbol tables to add label 'extensions' so that labels
              with more than 8 characters can be stored in elks executables.

       -z     produce "unmapped zero page" or "QMAGIC" executables

       All  the  options not taking an argument may be turned off by following
       the option letter by a '-', as for cc1.

PREDEFINED LABELS
       The linker predefines several labels that can  be  imported  into  user
       programs.

       __etext
              Standard C variable for the end of the text segment.

       __edata
              Standard C variable for the end of the initilised data.

       __end  Standard C variable for the end of the bss area.

       __segoff
              The  offset  within the executable file between the start of the
              text segment and the start  of  the  data  segment  in  16  byte
              'paragraphs'.   Note  this  is  zero  for  impure  (tiny  model)
              executables and is adjusted for executables that don't start  at
              offset 0 within the segment.

       __segXDL
              The lowest address with data in segment 'X'. (eg __seg0DL is for
              segment zero or the text  segment,  __seg3DL  is  for  the  data
              segment) The value 'X' is a hex digit.

       __segXDH
              The top of segment 'X's data area.

       __segXCL
              The  bottom  of  segment  'X's  'common data' or unitilised data
              area. Each segment has both an initilised  and  unitilised  data
              area.

       __segXCH
              The top of segment 'X's common area.

       __segXSO
              This  is  the  adjusted  offset  from  segment 0 of the start of
              segment 'X' in 'paragraphs'.


HISTORY
       The 6809 version does not support -i.

       The previous versions of the linker could produce  an  8086  executable
       with  segments  of  a  size  >64k,  now  only i386 executables may have
       segments this large.


BUGS
       The linker cannot deal with reverse seeks caused by org instructions in
       the  object  file.  Unlike  previous versions the current one traps the
       error rather than trying to fill up the hard disk.

       The linker produces a broken a.out object file if given one  input  and
       the -r option this is so it is compatible with pre-dev86 versions.



                                   Apr, 1997                           ld86(1)