CODEWITHSUNDEEP
linux-kernelkernel-moduleopenwrt
FirmwareRootkits
FirmwareRootkits

Reputation: 131

How do I write the makefile for a kernel module in OpenWrt to load the module automatically

I'm writing a simple kernel module for Openwrt. I have working code that loads and does what it needs to do. What I am missing is how to get the code into the build process of Openwrt. I have a Makefile as below:

# Copyright (C) 2006-2012 OpenWrt.org
#
# This is free software, licensed under the GNU General Public License v2.
# See /LICENSE for more information.

include $(TOPDIR)/rules.mk
include $(INCLUDE_DIR)/kernel.mk

# name
PKG_NAME:=HelloWorld
# version of what we are downloading
PKG_VERSION:=1.0
# version of this makefile
PKG_RELEASE:=0

PKG_BUILD_DIR:=$(KERNEL_BUILD_DIR)/$(PKG_NAME)
PKG_CHECK_FORMAT_SECURITY:=0

include $(INCLUDE_DIR)/package.mk

define KernelPackage/$(PKG_NAME)
    SUBMENU:=Other modules
    TITLE:=helloworld lkm
    FILES:= $(PKG_BUILD_DIR)/hello.ko
endef

define KernelPackage/$(PKG_NAME)/description
    A sample kernel module.
endef

define Build/Prepare
    mkdir -p $(PKG_BUILD_DIR)
    $(CP) ./src/* $(PKG_BUILD_DIR)/
endef

MAKE_OPTS:= \
    ARCH="$(LINUX_KARCH)" \
    CROSS_COMPILE="$(TARGET_CROSS)" \
    SUBDIRS="$(PKG_BUILD_DIR)"

define Build/Compile
    $(MAKE) -C "$(LINUX_DIR)" \
        $(MAKE_OPTS) \
        modules
endef

$(eval $(call KernelPackage,$(PKG_NAME)))

I'm trying to follow the instructions here: https://wiki.openwrt.org/doc/devel/packages#creating_packages_for_kernel_modules

Right now, I can see the module in the make menuconfig and select it. However when I run the build in QEMU I don't see the module. I can actually copy the *.ko module over and load it and that works. I just want the module to load automatically. How can I do that?

Upvotes: 4

Views: 4033

Answers (1)

oxr463
oxr463

Reputation: 1891

In Build/Compile, you need a line to include your module.

define Build/Compile $(MAKE) -C "$(LINUX_DIR)" \ $(MAKE_OPTS) \ CONFIG_<your mod>=m \ # THIS LINE IS MISSING modules endef

This are some good examples in the tree. Check out exfat-nofuse.

Upvotes: 4

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