NAME    [Toc]    [Back]

     genassym.sh - emit an assym.h file

SYNOPSIS    [Toc]    [Back]

     sh genassym.sh [-c] C compiler invocation

DESCRIPTION    [Toc]    [Back]

     genassym.sh is a shell script normally used during the  kernel build process
  to create an assym.h file.  This file defines a number
of cpp constants
   derived   from   the   configuration    information
genassym.sh reads from
     stdin.  The generated file is used by kernel sources written
in assembler
     to gain access to information (e.g.  structure  offsets  and
sizes) normally
     only known to the C compiler.

     genassym.sh  resides  in the /sys/kern directory.  Arguments
to genassym.sh
     are usually of the form ${CC}  ${CFLAGS}  ${CPPFLAGS}  where
${CC} is the C
     compiler  used  to  compile  the kernel, while ${CFLAGS} and
${CPPFLAGS} are
     flag arguments to the C compiler.  The script  creates  a  C
source file
     from  its input.  Then the C compiler is called according to
the script's
     arguments to compile this file.

     Normally genassym.sh instructs the C compiler to  create  an
assembler
     source from the constructed C source.  The resulting file is
then processed
 to extract the information needed to create  the  assym.h file.  The
     -c  flag  instructs genassym.sh to create slightly different
code, generate
     an executable from this code and run it.  In both cases  the
assym.h file
     is written to stdout.

DIAGNOSTICS    [Toc]    [Back]

     Either self-explanatory, or generated by one of the programs
called from
     the script.  The script will exit with the return code  from
the compiler,
     or,  in the -c case, with the return code from the generated
executable.

SEE ALSO    [Toc]    [Back]

     genassym.cf(5)

HISTORY    [Toc]    [Back]

     The genassym.sh script first appeared in OpenBSD 2.2.

OpenBSD     3.6                        January      25,      1997