i want to use iostream or stdlib.h in my linux kernel driver and i have this MakeFile
ifeq ($(KERNELRELEASE),)
KERNELDIR ?= /lib/modules/$(shell uname -r)/build
PWD := $(shell pwd)
.PHONY: build clean
build:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
clean:
rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c
else
$(info Building with KERNELRELEASE = ${KERNELRELEASE})
obj-m := mydev.o
endif
when i use #include in my driver code, make returns this
mydev.c:10:20: fatal error: iostream: No such file or directory
#include <iostream>
what should i add to my makefile?
iostream is a C++ header. The Kernel is written in C
Related
obj-m += hello.0
KDIR = /usr/src/linux-headers-3.16.0-34-generic
all :
$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules
clean:
rm -rf *.o
error is: Makefile:9: *** missing separator. Stop.
You can use the below Makefile to build the kernel module. Comments inlined in the Makefile
There is an extra space before $(MAKE) in your makefile
obj-m = hello.o
KDIR = /usr/src/linux-headers-3.16.0-34-generic
# Here the commands to build the target should start in the next line with a tab space
all:
<TAB>make -C $(KDIR) M=$(PWD) modules
clean:
<TAB>make -C $(KDIR) M=$(PWD) clean
I'm writing a character driver to sit on top of a modified version of ahci in the source tree. I basically have something that looks like this:
topdir
|
|- Makfile
|
|- mod_ahci
| | - Makefile, codefiles
|
|- char_interface
| | - Makefile, codefiles
now, char_interface requires symbols from mod_ahci. I have the appropriate EXPORT_SYMBOL() macro use for the symbols I need to export. However, I'm having trouble getting the makefiles right to pick up the header file in mod_ahci from char_interface. My toplevel Makefile
ifneq ($(KERNELRELEASE),)
obj-y := mod_ahci/ char_interface/
else
KERNELDIR ?= /lib/modules/$(shell uname -r)/build
PWD := $(shell pwd)
default:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
modules_install:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules_install
endif
The makefile for char_interface (because the other builds just fine)
ifneq ($(KERNELRELEASE),)
ccflags-y += -I../mod_ahci
obj-m := char_interface.o
else
KERNELDIR ?= /lib/modules/$(shell uname -r)/build
default:
$(MAKE) -C $(KERNELDIR) M=$(shell pwd) modules
modules_install:
$(MAKE) -C $(KERNELDIR) M=$(shell pwd) modules_install
endif
clean:
-sudo rmmod ahcip
-rm -f *.ko* *.mod.* *.o modules.order Modules.symvers
I have referenced various text files in the kernel documentation. For example, I'm referring to .../Documentation/kbuild/makefiles.txt right now as well as .../Documentation/kbuild/modules.txt. Whenever I build, I'm getting /home/captaink/devel/kmodtests/char_interface/char_interface.c:2:22: error: mod_ahci.h: No such file or directory. There is a file named mod_ahci.h in the directory ../mod_ahci. What am I getting wrong with my use of ccflags-y in the makefile for the char driver?
Thanks
After some digging, I found the answer to the problem. I was misunderstanding what was happening with the makefile's that I was viewing from LDD3 and the kernel documentation (which is, apparently, exactly where O'Reilly took their examples). The build system actually changes directories into /usr/src/kernels/$(uname -r)/build (or similar) because this is why my header file wasn't being found by the compiler.
I'm not saying this is an elegant way of doing this, but here's how I fixed it. The makefile in the top directory now looks like:
ifneq ($(KERNELRELEASE),)
obj-y := mod_ahci/ char_interface/
else
KERNELDIR ?= /lib/modules/$(shell uname -r)/build
PWD := $(shell pwd)
default:
$(MAKE) -C $(KERNELDIR) M=$(PWD) TOP_DIR=$(PWD) modules
modules_install:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules_install
endif
And the makefile in the subdirectory containing the char driver interface looks like:
ifneq ($(KERNELRELEASE),)
ccflags-y += -I$(TOP_DIR)/mod_ahci
obj-m := char_interface.o
else
KERNELDIR ?= /lib/modules/$(shell uname -r)/build
default:
$(MAKE) -C $(KERNELDIR) M=$(shell pwd) modules
modules_install:
$(MAKE) -C $(KERNELDIR) M=$(shell pwd) modules_install
endif
clean:
-sudo rmmod ahcip
-rm -f *.ko* *.mod.* *.o modules.order Modules.symvers
As you can tell, the makefiles have been copied extensively. The subdirectories probably don't need the "shared" makefile stuff in them because that's taken care of by the higher level makefile. Nevertheless, the modules now build and the character driver I have knows of the exported symbols I made in my modified ahci driver.
I hope this may help someone who's a neophyte, like myself, to the Linux kernel build world and Linux kernel drivers.
I am inserting kernel module insmod hello.ko, it gives:
insmod: can't insert 'hello.ko': kernel does not support requested operation.
I am using same uImage on target.
Module compilation was successful. Before make I have set
export ARCH=arm
export CROSS_COMPILE=arm-linux-gnueabihf-.,
export PATH=$PATH:/home/bsp/rskrza1_bsp-master/output/gcc-linaro-arm-linux-gnueabihf-4.8-2014.02_linux/bin/
Makefile is
obj-m := hello.o
KERNELDIR ?= /home/bsp/rskrza1_bsp-master/output/linux-3.14/
PWD := $(shell pwd)
all:
$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
clean:
rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions
Please let me know how can I solve it.
Thanks, Awadhesh
This is my makefile:
ifneq ($(KERNELRELEASE),)
obj-m := dmcdus_dd.o
else
KDIR := /usr/src/linux-headers-3.13.0-24-generic/
all:
$(MAKE) INSTALL_MOD_DIR=kernel/drivers/input/touchscreen -C $(KDIR) M=$$PWD modules_install
endif
clean:
rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions sample Module.symvers
I have specified my required path where i have to move my dmcdus_dd.ko file using INSTALL_MOD_DIR & install it by modules_install. When i type "make" in the console i get the following results in the console:
make INSTALL_MOD_DIR=kernel/drivers/input/touchscreen -C /usr/src/linux-headers-3.5.0-49-generic/ M=$PWD modules_install
make[1]: Entering directory `/usr/src/linux-headers-3.5.0-49-generic'
DEPMOD 3.5.0-49-generic
make[1]: Leaving directory `/usr/src/linux-headers-3.5.0-49-generic'
But when i go to the location "/lib/modules/3.5.0-49-generic/kernel/drivers/input/touchscreen" i dont see dmcdus.ko file in that directory... How can i copy my driver to that location?
Before installing first you need to make module using make -C $(KDIR) M=$(PWD) modules.
If you want to make little change in your makefile then write in following way:
ifneq ($(KERNELRELEASE),)
obj-m := dmcdus_dd.o
else
KDIR := /usr/src/linux-headers-3.13.0-24-generic/
all:
make -C $(KDIR) M=$(PWD) modules #I've changed makefile here
$(MAKE) INSTALL_MOD_DIR=kernel/drivers/input/touchscreen -C $(KDIR) M=$$PWD modules_install
endif
clean:
rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions sample Module.symvers
And make sure that you have permission to copy file to destination (/input/touchscreen)folder. If not then change it.
The below makefile is sufficient for you to build and install module
obj-m := dmcdus_dd.o
KDIR := /usr/src/linux-headers-3.13.0-24-generic/
all:
make -C $(KDIR) M=$$PWD modules
make -C $(KDIR) M=$$PWD modules_install
clean:
make -C $(KDIR) M=$$PWD clean
If you specify INSTALL_MOD_DIR then the modules is moved to that directory
make INSTALL_MOD_DIR=kernel/drivers/input/touchscreen -C $(KDIR) M=$$PWD modules_install
I'm trying to cross compile a helloworld kernel (2.6.x) module for ARM architecture on my intel x86 host.
The codesourcery tool chain for ARM is located at: /home/ravi/workspace/hawk/arm-2009q3
The kernel source is located at :/home/ravi/workspace/hawk/linux-omapl1
My Makefile:
ARCH=arm
CROSS_COMPILE=arm-none-linux-gnueabi
obj-m := Hello.o
KDIR := /home/ravi/workspace/hawk/linux-omapl1
PWD := $(shell pwd)
default:
$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules
clean:
$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) clean
When i run make, the .ko produced is that of my host machine which means the makefile is invoking the native compiler instead of the cross compiler.What am I doing wrong? The cross compiler's binaries are in my path.
Putting ARCH and CROSS_COMPILE in the Makefile doesn't work. You need to put them on the command line:
make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi-
Replace
ARCH=arm
CROSS_COMPILE=arm-none-linux-gnueabi
by
export ARCH:=arm
export CROSS_COMPILE:=arm-none-linux-gnueabi-
this will also work if you do not want to give these parameter command line each time.
Sidenote: SUBDIRS= is deprecated in favor of M=.
could you try, you forgot to add ARCH and CROSS_COMPILE into the default and clean
ARCH=arm
COMPILER=arm-none-linux-gnueabi
obj-m := Hello.o
KERNELDIR := /home/ravi/workspace/hawk/linux-omapl1
PWD := $(shell pwd)
default:
$(MAKE) -C $(KERNELDIR) M=$(PWD) ARCH=$(ARCH) CROSS_COMPILE=$(COMPILER) modules
clean:
$(MAKE) -C $(KERNELDIR) M=$(PWD) ARCH=$(ARCH) clean
adding export at the end of your Makefile variable declarations will make them available to subshells. and add the dash to the CROSS_COMPILE prefix as JayM pointed out, and M instead of SUBDIRS as user502515 answered.
and it's generally a good idea to use := rather than = in a Makefile, so the variable only gets interpolated once. really doesn't matter in this particular case though.
ARCH := arm
CROSS_COMPILE := arm-none-linux-gnueabi-
obj-m := Hello.o
KDIR := /home/ravi/workspace/hawk/linux-omapl1
PWD := $(shell pwd)
export
default:
$(MAKE) -C $(KDIR) M=$(PWD) modules
clean:
$(MAKE) -C $(KDIR) M=$(PWD) clean
MODULES := hola_kern.o
#guest architecture
ARCH := arm
CROSS_COMPILE := arm-linux-gnueabi-
obj-m := $(MODULES)
#path of the arm compiled kernel
ROOTDIR := /home/aldo/c/proyectos/prefixa/work/kernels/linux-omap-5f0a6e2
MAKEARCH := $(MAKE) ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE)
all: modules
modules:
$(MAKEARCH) -C $(ROOTDIR) M=${shell pwd} modules
clean:
$(MAKEARCH) -C $(ROOTDIR) M=${shell pwd} clean