GENASSYM.SH(8) OpenBSD System Manager's Manual GENASSYM.SH(8)NAMEgenassym.sh - emit an assym.h file
SYNOPSIS
sh genassym.sh [-c] C compiler invocation
DESCRIPTIONgenassym.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
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 ALSOgenassym.cf(5)HISTORY
The genassym.sh script first appeared in OpenBSD 2.2.
OpenBSD 4.9 May 31, 2007 OpenBSD 4.9
