NAME
genassym —
emit an assym.h file
SYNOPSIS
genassym |
[-c]
[-f] C compiler
invocation |
DESCRIPTION
genassym 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 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.
Arguments to
genassym 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 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 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. The
-f
flag instructs
genassym to create forth code.
DIAGNOSTICS
Either self-explanatory, or generated by one of the programs called from the
script.
SEE ALSO
genassym.cf(5)
HISTORY
The
genassym command appeared in
NetBSD
1.3 as “genassym.sh” in
/usr/src/sys/kern. It became a userland utility in
NetBSD 4.0.