10

我正面临 Linux 内核构建系统（Kbuild，内核≥2.6.28）的目录结构和更大项目的构建系统。我们的项目包含一个 out-of-tree Linux 内核模块，我们的目录结构如下所示（显然是简化了）：

checkout/src/common/*.c           source files (common to Linux and other platforms)
checkout/src/linux-driver/*.c     source files (for the Linux kernel driver)
checkout/build/linux/Kbuild       Kbuild
tmp/linux-2.6.xx/                 where the Linux kernel is unpacked and configured
output/linux-arm-debug/           where object files must end up

构建过程不得修改下checkout的任何内容，构建模块不得修改下的任何内容tmp/linux-2.6.xx。所有输出文件必须以output/linux-arm-debug（或在构建时选择的任何架构和调试变体）结束。

我已经阅读kbuild/modules.txt，并开始编写我的Kbuild文件：

MOD_OUTPUT_DIR = ../../../output/linux-$(ARCH)-$(DEBUG)
obj-m += $(MOD_OUTPUT_DIR)/foo_mod.o
$(MOD_OUTPUT_DIR)/our_module-objs := $(MOD_OUTPUT_DIR)/foo_common.o $(MOD_OUTPUT_DIR)/foo_linux.o

这处理将对象文件存储在与所在位置不同的目录中Kbuild。现在我如何指定foo_common.o需要从…/checkout/src/common/foo_common.c和foo_linux.o从编译…/checkout/src/linux-driver/foo_linux.c？

4

6 回答 6

9

这是一个Makefile，它为内核树模块之外的源树构建（改编自@Mark的评论）......

KDIR ?= /lib/modules/$(shell uname -r)/build
BUILD_DIR ?= $(PWD)/build
BUILD_DIR_MAKEFILE ?= $(PWD)/build/Makefile

default: $(BUILD_DIR_MAKEFILE)
    make -C $(KDIR) M=$(BUILD_DIR) src=$(PWD) modules

$(BUILD_DIR):
    mkdir -p "$@"

$(BUILD_DIR_MAKEFILE): $(BUILD_DIR)
    touch "$@"

clean:
    make -C $(KDIR) M=$(BUILD_DIR) src=$(PWD) clean

注意：您仍然需要一个 Kbuild 文件...

obj-m += my_driver.o
于 2016-06-16T11:48:51.863 回答
3

我有一个类似的问题。我修改linux_2_6_34/scripts/Makefile.build如下。

ifdef SRCDIR
src := $(SRCDIR)
else
src := $(obj)
endif

SRCDIR是目录源。

要编译模块，请运行

make -c $(KDIR) M=$(Your_output_dir) SRCDIR=$(your source directory)`
于 2013-12-11T04:57:53.170 回答
2

我不优雅但有效的解决方案是将源文件复制到输出树中。

FOO_SOURCES_DIR = $(src)/../../../checkout/src
FOO_MOD_OUTPUT_DIR = ../../../output/linux-$(ARCH)-$(DEBUG)

# Specify the object files
obj-m += $(FOO_MOD_OUTPUT_DIR)/foo_mod.o
FOO_MODULE_OBJS := $(FOO_MOD_OUTPUT_DIR)/foo_common.o $(FOO_MOD_OUTPUT_DIR)/foo_linux.o
$(FOO_MOD_OUTPUT_DIR)/foo_mod-objs := $(FOO_MODULE_OBJS)

# Where to find the sources
$(src)/$(FOO_MOD_OUTPUT_DIR)/foo_common.c: $(FOO_SOURCES_DIR)/common/foo_common.c
$(src)/$(FOO_MOD_OUTPUT_DIR)/foo_linux.c: $(FOO_SOURCES_DIR)/linux-driver/foo_linux.c

# Rules to copy the sources
FOO_COPIED_SOURCES = $(patsubst %.o,$(src)/%.c,$(FOO_MODULE_OBJS))
$(FOO_COPIED_SOURCES):
        $(Q)mkdir -p $(@D)
        cp -f $< $@
clean-files += $(FOO_COPIED_SOURCES)
clean-dirs += $(FOO_MOD_OUTPUT_DIR)
于 2011-04-28T19:49:30.753 回答
1

虽然您还没有提到到目前为止您已经尝试过什么（或者您是否已经找到了解决方案），但看起来您只需要继续深入modules.txt文件——到第 4.3 节：

--- 4.3 Several Subdirectories

kbuild can handle files that are spread over several directories.
Consider the following example:

.
|__ src
|   |__ complex_main.c
|   |__ hal
|   |__ hardwareif.c
|   |__ include
|       |__ hardwareif.h
|__ include
    |__ complex.h

To build the module complex.ko, we then need the following
kbuild file:

    --> filename: Kbuild
    obj-m := complex.o
    complex-y := src/complex_main.o
    complex-y += src/hal/hardwareif.o

    ccflags-y := -I$(src)/include
    ccflags-y += -I$(src)/src/hal/include

As you can see, kbuild knows how to handle object files located
in other directories. The trick is to specify the directory
relative to the kbuild file's location. That being said, this
is NOT recommended practice.

For the header files, kbuild must be explicitly told where to
look. When kbuild executes, the current directory is always the
root of the kernel tree (the argument to "-C") and therefore an
absolute path is needed. $(src) provides the absolute path by
pointing to the directory where the currently executing kbuild
file is located.
于 2011-04-28T19:36:24.897 回答
0

有点晚了，但看起来O= 标志是你需要的。

于 2012-05-30T21:57:33.987 回答
-1

您可以设置环境变量KBUILD_OUTPUT。此功能类似于O=选项；但是，由于它是一个环境变量，它可以跨越多个O=无法传递的 makefile，或者需要构建目录外模块。我在尝试构建一组兼容无线模块时遇到了同样的问题，我需要O=用于实际的内核映像构建。

于 2012-12-11T00:40:07.407 回答