8L(1)                                                       8L(1)

     NAME
          0l, 5l, 6l, 8l, 9l, kl, ql, vl - loaders

     SYNOPSIS
          8l [ option ... ] [ file ... ]
          etc.

     DESCRIPTION
          These commands load the named files into executable files
          for the corresponding architectures; see 8c(1) for the cor-
          respondence between an architecture and the character (6, 8,
          etc.) that specifies it.  The files should be object files
          or libraries (archives of object files) for the appropriate
          architecture.  Also, a name like -lext represents the
          library libext.a in /$objtype/lib, where objtype is one of
          386, etc. as listed in 8c(1). If the environment variable
          ccroot is defined, the library is sought in
          $ccroot/$objtype/lib instead.  The libraries must have
          tables of contents (see ar(1)).

          In practice, -l options are rarely necessary as the header
          files for the libraries cause their archives to be included
          automatically in the load (see 8c(1)). For example, any pro-
          gram that includes header file libc.h causes the loader to
          search the C library /$objtype/lib/libc.a.  Also, the loader
          creates an undefined symbol _main (or _mainp if profiling is
          enabled) to force loading of the startup linkage from the C
          library.

          The order of search to resolve undefined symbols is to load
          all files and libraries mentioned explicitly on the command
          line, and then to resolve remaining symbols by searching in
          topological order libraries mentioned in header files
          included by files already loaded.  When scanning such
          libraries, the algorithm is to scan each library repeatedly
          until no new undefined symbols are picked up, then to start
          on the next library.  Thus if library A needs B which needs
          A again, it may be necessary to mention A explicitly so it
          will be read a second time.

          The loader options are:

          -l     (As a bare option.)  Suppress the default loading of
                 the startup linkage and libraries specified by header
                 files.

          -o out Place output in file out. Default is O.out, where O
                 is the first letter of the loader name.

          -p     Insert profiling code into the executable output; no

     8L(1)                                                       8L(1)

                 special action is needed during compilation or assem-
                 bly.

          -e     Insert (embedded) tracing code into the executable
                 output; no special action is needed during compila-
                 tion or assembly.  The added code calls `_tracein' at
                 function entries and `_traceout' at function exits.

          -s     Strip the symbol tables from the output file.

          -a     Print the object code in assembly language, with
                 addresses.

          -v     Print debugging output that annotates the activities
                 of the load.

          -M     (Kl only) Generate instructions rather than calls to
                 emulation routines for multiply and divide.

          -Esymbol
                 The entry point for the binary is symbol (default
                 _main; _mainp under -p).

          -x [ file ]
                 Produce an export table in the executable.  The
                 optional file restricts the exported symbols to those
                 listed in the file.  See dynld(2).

          -u [ file ]
                 Produce an export table, import table and a dynamic
                 load section in the executable.  The optional file
                 restricts the imported symbols to those listed in the
                 file.  See dynld(2).

          -t     (5l and vl only) Move strings into the text segment.

          -f     (5l only) Generate VFP hardware floating-point
                 instructions.  Without this option, 5l generates
                 arm7500 floating-point instructions which are emu-
                 lated in the kernel.

          -Hn    Executable header is type n. The meaning of the types
                 is architecture-dependent; typically type 1 is Plan 9
                 boot format and type 2 is the regular Plan 9 format,
                 the default.  These are reversed on the MIPS.  The
                 Next boot format is 3.  Type 4 in vl creates a MIPS
                 executable for an SGI Unix system.  There is often a
                 type that produces ELF or ELF64 format; 5 for ELF is
                 common.  See obj.c in the source directory for a com-
                 plete list.

          -k     (ELF only) Executable is a standalone boot image or

     8L(1)                                                       8L(1)

                 kernel.

          -Tt    The text segment starts at (virtual) address t.

          -Pt    (ELF only) The text segment starts at physical
                 address t (by default the text segment's virtual
                 start address).

          -Dd    The data segment starts at address d.

          -Rr    The text segment is rounded to a multiple of r (if r
                 is nonzero).

          -Ldir  For a library reference -lext, search dir before
                 looking in the standard library directory.  If more
                 than one -L option is given, directories will be
                 searched in order of appearance.

          The numbers in the above options can begin with `0x' or `0'
          to change the default base from decimal to hexadecimal or
          octal.  The defaults for the values depend on the compiler
          and the header type.

          The loaded image has several symbols inserted by the loader:
          etext is the address of the end of the text segment; bdata
          is the address of the beginning of the data segment; edata
          is the address of the end of the data segment; and end is
          the address of the end of the bss segment, and of the pro-
          gram.

     FILES
          /$objtype/lib  for -llib arguments.

     SOURCE
          /sys/src/cmd/8l, etc.

     SEE ALSO
          8c(1), 8a(1), ar(1), nm(1), db(1), prof(1)

          Rob Pike, ``How to Use the Plan 9 C Compiler''

     BUGS
          The list of loaders given above is only partial, not all
          architectures are supported on all systems, some have been
          retired and some are provided by third parties.