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.