lkhh-module-init

#! /bin/bash

_rootdir=${_rootdir:-"$(dirname "$(readlink -f "$0")")"}
_ver="0.0.1-dev"
#_author="Wei Peng <me@1pengw.com>"

source "${_rootdir}/_shared_prologue"

#
# parameters
#
declare moduleroot=${moduleroot:-"$(readlink -f $PWD)"}
declare -i main=0
declare -i force=0

#
# getopt processing
#
function my_getopt_cont () {
    local n_shift=1 # number of shifts in the outer loop; shift by 1 by default
    case "$1" in
        -m|--moduleroot)
            shift
            moduleroot=$1
            n_shift=2
            ;;
        -M|--main)
			((main++))
            n_shift=1
            ;;
        -f|--force)
			((force++))
            n_shift=1
            ;;
    esac
    return $n_shift
}

my_getopt "m:Mf" "moduleroot:,main,force" "my_getopt_cont" "Create a template Makefile" "$(
cat <<END
[-m|--moduleroot=<moduleroot>] [-M|--main]
	[-f|--force]
END
)" "$(
cat <<END
-m	--moduleroot		Root directory of the module, where "Makefile" is found (default: $moduleroot).
-M	--main		Create a main.c (default: $main).
-f	--force		Forcibly create a file even if it exists (default: $force).
END
)" "$@"
ret=$?
eval set -- "$_getopt"
shift $ret 

# sanity check
vecho 0 <<END
$(
dumpparam <<END1
$(
for name in moduleroot main force; do
    echo "$name=$(echo $(eval "echo \$$name"))"
done
)
END1
)
END

if [[ ! -d "$moduleroot" ]]; then
	mkdir -p "$moduleroot"
fi

moduleroot="$(readlink -f "$moduleroot")"

[[ -d "$moduleroot" ]] || die 1 <<END
ERROR: $moduleroot does not exist.
END

module=$(basename "$moduleroot" | tr -d '[:cntrl:]' | tr -s '[:space:]-' '[_*]')

#
# main.c
#

mainfile="$moduleroot/main.c"
if (( main > 0 )); then
	if [[ ! -f "$mainfile" ]] || (( force > 0 )); then
		>"$mainfile" cat - <<END
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/fs.h>

int ${module}_param = 0;

module_param(${module}_param, int, 0644);

static int ${module}_init(void)
{
    pr_debug("Hello, world.\n");
    return 0;
}

static void ${module}_exit(void)
{
    pr_debug("Goodbye, world.\n");
}

MODULE_AUTHOR("$(whoami)");
MODULE_LICENSE("Dual BSD/GPL");
module_init(${module}_init);
module_exit(${module}_exit);
END
	fi
fi

#
# Makefile
#

makefile="$moduleroot/Makefile"

>/dev/null pushd $moduleroot
objfiles=$(2>/dev/null find * -name '*.c' -type f | sed 's/^\(.*\).c$/\1.o/' | tr "\n" " ")
>/dev/null popd

[[ -f "$makefile" ]] && (( force <= 0 )) && die 0 <<END
$makefile exists; use -f/--force to forcibly create a new one.
END


>"$makefile" cat - <<END
_name=Makefile.pre
ifeq (\$(_name),\$(wildcard \$(_name)))
include \$(_name)
endif

ifeq (\$(DEBUG),y)
DEBFLAGS = -O -g -DDEBUG # "-O" is needed to expand inlines
else
DEBFLAGS = -O2
endif

LOCALINC=\$(PWD)

EXTRA_CFLAGS += \$(DEBFLAGS)
EXTRA_CFLAGS += -I\$(LOCALINC)
EXTRA_CFLAGS += -std=gnu17

ifneq (\$(KERNELRELEASE),)
# call from kernel build system

${module}-objs := ${objfiles}

obj-m	:= ${module}.o

else

KERNELDIR ?= /lib/modules/\$(shell uname -r)/build
PWD       := \$(shell pwd)

modules:
	\$(MAKE) -C \$(KERNELDIR) M=\$(PWD) modules

endif

clean:
	rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions .*.o.d

depend .depend dep:
	\$(CC) \$(EXTRA_CFLAGS) -M *.c > .depend

ifeq (.depend,\$(wildcard .depend))
include .depend
endif


_name=Makefile.post
ifeq (\$(_name),\$(wildcard \$(_name)))
include \$(_name)
endif
END