是否可以将CFLAGS设置为Linux内核模块Makefile? [英] Is it possible to set CFLAGS to a linux kernel module Makefile?

问题描述

例如:通用设备模块的Makefile

Eg: a common device module's Makefile

obj-m:=jc.o

default:
    $(MAKE) -C /lib/modules/$(shell uname -r)/build M=$(shell pwd) modules
clean:
    $(MAKE) -C /lib/modules/$(shell uname -r)/build M=$(shell pwd) modules clean

我考虑是否可以将CFLAGS设置为文件.当我将 default 部分更改为

I consider if I can set CFLAGS to the file. When I change default section to

$(MAKE) -O2 -C /lib/modules/$(shell uname -r)/build M=$(shell pwd) modules

但是没有用.

有帮助吗?非常感谢.

推荐答案

-O2将是make(或$(MAKE)，在使用时)的一个选项.显然，编译器(可能是gcc)需要此标志，而不是make.

-O2 would be an option to make (or $(MAKE), as you're using it) in what you tried. Obviously, the compiler (probably gcc) needs this flag, not make.

Kbuild理解一个名为CFLAGS_modulename.o的make变量，用于在编译此单元时添加特定的C标志.在您的情况下，您的模块对象将为jc.o，因此您可以指定:

Kbuild understands a make variable named CFLAGS_modulename.o to add specific C flags when compiling this unit. In your case, your module object will be jc.o, so you can specify:

CFLAGS_jc.o := -O2

，它应该可以工作.在$(MAKE)行中添加V=1以得到详细的输出，并且在编译jc.c时应该会看到-O2.

and it should work. Add V=1 to your $(MAKE) lines to get a verbose output and you should see -O2 when jc.c is being compiled.

您可以在官方文档中找到有关编译模块的更多信息.

You can find more about compiling modules in the official documentation.

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