linking user space and kernel space programs with qmake

[jacek]

Try changing:

QMAKE_LIBS_X11 += -lkdeui -lkdecore

QMAKE_LIBS_X11 += -lkdeui -lkdecore

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to

LIBS += -lkdeui -lkdecore -lcomedi -lrtai

LIBS += -lkdeui -lkdecore -lcomedi -lrtai

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Remember to rerun qmake to get a new Makefile.

[zielchri]

That gave me better results, but it isn't right yet. When I made that change I got the following:

smart-microsystem-lab:~/test # QTDIR=/usr/lib/qt3 make

g++  -o KDEMenu obj/KDEMenu.o obj/RT_DAQ.o obj/moc_KDEMenu.o  -L/usr/lib/ -L/usr/lib/qt3/lib/ -L/usr/lib/ -L/usr/X11R6/lib/ -L/opt/kde3/lib -L/usr/lib -lkdeui -lkdecore -lcomedi -lrtai -lqt -lGLU -lGL -lXmu -lXext -lX11 -lm
/usr/lib/gcc-lib/i586-suse-linux/3.3.1/../../../../i586-suse-linux/bin/ld: cannot find -lrtai
collect2: ld returned 1 exit status
make: *** [KDEMenu] Error 1

g++  -o KDEMenu obj/KDEMenu.o obj/RT_DAQ.o obj/moc_KDEMenu.o  -L/usr/lib/ -L/usr/lib/qt3/lib/ -L/usr/lib/ -L/usr/X11R6/lib/ -L/opt/kde3/lib -L/usr/lib -lkdeui -lkdecore -lcomedi -lrtai -lqt -lGLU -lGL -lXmu -lXext -lX11 -lm
/usr/lib/gcc-lib/i586-suse-linux/3.3.1/../../../../i586-suse-linux/bin/ld: cannot find -lrtai
collect2: ld returned 1 exit status
make: *** [KDEMenu] Error 1

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So then I decided to get rid of -lrtai in that line just out of curiosity and got the following:

smart-microsystem-lab:~/test # qmake menu.pro -o Makefile
smart-microsystem-lab:~/test # QTDIR=/usr/lib/qt3 make

g++  -o KDEMenu obj/KDEMenu.o obj/RT_DAQ.o obj/moc_KDEMenu.o  -L/usr/lib/ -L/usr/lib/qt3/lib/ -L/usr/lib/ -L/usr/X11R6/lib/ -L/opt/kde3/lib -L/usr/lib -lkdeui -lkdecore -lcomedi -lqt -lGLU -lGL -lXmu -lXext -lX11 -lm
obj/RT_DAQ.o(.text+0x26): In function `set_volts':
/root/test/RT_DAQ.c:61: undefined reference to `printk'
obj/RT_DAQ.o(.text+0x2b):/root/test/RT_DAQ.c:62: undefined reference to `rt_task_wait_period'
obj/RT_DAQ.o(.text+0x39):/root/test/RT_DAQ.c:102: undefined reference to `rt_task_wait_period'
obj/RT_DAQ.o(.text+0x5a):/root/test/RT_DAQ.c:92: undefined reference to `rt_get_cpu_time_ns'
obj/RT_DAQ.o(.text+0xe6):/root/test/RT_DAQ.c:94: undefined reference to `rt_sleep'
obj/RT_DAQ.o(.text+0x123):/root/test/RT_DAQ.c:96: undefined reference to `rt_get_time_ns'
obj/RT_DAQ.o(.text+0x141):/root/test/RT_DAQ.c:99: undefined reference to `rtf_put'
obj/RT_DAQ.o(.text+0x15c):/root/test/RT_DAQ.c:100: undefined reference to `rtf_put'
obj/RT_DAQ.o(.text+0x18e): In function `init_module':
/root/test/RT_DAQ.c:108: undefined reference to `printk'
obj/RT_DAQ.o(.text+0x193):/root/test/RT_DAQ.c:109: undefined reference to `rt_get_time'
obj/RT_DAQ.o(.text+0x1b5):/root/test/RT_DAQ.c:113: undefined reference to `rt_shm_alloc'
obj/RT_DAQ.o(.text+0x21d):/root/test/RT_DAQ.c:116: undefined reference to `rt_task_init'
obj/RT_DAQ.o(.text+0x254):/root/test/RT_DAQ.c:117: undefined reference to `rt_task_init'
obj/RT_DAQ.o(.text+0x268):/root/test/RT_DAQ.c:118: undefined reference to `rtf_create'
obj/RT_DAQ.o(.text+0x27c):/root/test/RT_DAQ.c:119: undefined reference to `rtf_create'
obj/RT_DAQ.o(.text+0x290):/root/test/RT_DAQ.c:120: undefined reference to `nano2count'
obj/RT_DAQ.o(.text+0x298):/root/test/RT_DAQ.c:120: undefined reference to `start_rt_timer'
obj/RT_DAQ.o(.text+0x2ce):/root/test/RT_DAQ.c:121: undefined reference to `rt_task_make_periodic'
obj/RT_DAQ.o(.text+0x30c): In function `cleanup_module':
/root/test/RT_DAQ.c:129: undefined reference to `stop_rt_timer'
obj/RT_DAQ.o(.text+0x318):/root/test/RT_DAQ.c:130: undefined reference to `rt_busy_sleep'
obj/RT_DAQ.o(.text+0x320):/root/test/RT_DAQ.c:131: undefined reference to `rt_task_delete'
obj/RT_DAQ.o(.text+0x32c):/root/test/RT_DAQ.c:132: undefined reference to `rt_shm_free'
obj/RT_DAQ.o(.text+0x338):/root/test/RT_DAQ.c:133: undefined reference to `rtf_destroy'
obj/RT_DAQ.o(.text+0x344):/root/test/RT_DAQ.c:134: undefined reference to `rtf_destroy'
obj/RT_DAQ.o(.text+0x34c):/root/test/RT_DAQ.c:135: undefined reference to `rt_task_delete'
collect2: ld returned 1 exit status
make: *** [KDEMenu] Error 1

g++  -o KDEMenu obj/KDEMenu.o obj/RT_DAQ.o obj/moc_KDEMenu.o  -L/usr/lib/ -L/usr/lib/qt3/lib/ -L/usr/lib/ -L/usr/X11R6/lib/ -L/opt/kde3/lib -L/usr/lib -lkdeui -lkdecore -lcomedi -lqt -lGLU -lGL -lXmu -lXext -lX11 -lm
obj/RT_DAQ.o(.text+0x26): In function `set_volts':
/root/test/RT_DAQ.c:61: undefined reference to `printk'
obj/RT_DAQ.o(.text+0x2b):/root/test/RT_DAQ.c:62: undefined reference to `rt_task_wait_period'
obj/RT_DAQ.o(.text+0x39):/root/test/RT_DAQ.c:102: undefined reference to `rt_task_wait_period'
obj/RT_DAQ.o(.text+0x5a):/root/test/RT_DAQ.c:92: undefined reference to `rt_get_cpu_time_ns'
obj/RT_DAQ.o(.text+0xe6):/root/test/RT_DAQ.c:94: undefined reference to `rt_sleep'
obj/RT_DAQ.o(.text+0x123):/root/test/RT_DAQ.c:96: undefined reference to `rt_get_time_ns'
obj/RT_DAQ.o(.text+0x141):/root/test/RT_DAQ.c:99: undefined reference to `rtf_put'
obj/RT_DAQ.o(.text+0x15c):/root/test/RT_DAQ.c:100: undefined reference to `rtf_put'
obj/RT_DAQ.o(.text+0x18e): In function `init_module':
/root/test/RT_DAQ.c:108: undefined reference to `printk'
obj/RT_DAQ.o(.text+0x193):/root/test/RT_DAQ.c:109: undefined reference to `rt_get_time'
obj/RT_DAQ.o(.text+0x1b5):/root/test/RT_DAQ.c:113: undefined reference to `rt_shm_alloc'
obj/RT_DAQ.o(.text+0x21d):/root/test/RT_DAQ.c:116: undefined reference to `rt_task_init'
obj/RT_DAQ.o(.text+0x254):/root/test/RT_DAQ.c:117: undefined reference to `rt_task_init'
obj/RT_DAQ.o(.text+0x268):/root/test/RT_DAQ.c:118: undefined reference to `rtf_create'
obj/RT_DAQ.o(.text+0x27c):/root/test/RT_DAQ.c:119: undefined reference to `rtf_create'
obj/RT_DAQ.o(.text+0x290):/root/test/RT_DAQ.c:120: undefined reference to `nano2count'
obj/RT_DAQ.o(.text+0x298):/root/test/RT_DAQ.c:120: undefined reference to `start_rt_timer'
obj/RT_DAQ.o(.text+0x2ce):/root/test/RT_DAQ.c:121: undefined reference to `rt_task_make_periodic'
obj/RT_DAQ.o(.text+0x30c): In function `cleanup_module':
/root/test/RT_DAQ.c:129: undefined reference to `stop_rt_timer'
obj/RT_DAQ.o(.text+0x318):/root/test/RT_DAQ.c:130: undefined reference to `rt_busy_sleep'
obj/RT_DAQ.o(.text+0x320):/root/test/RT_DAQ.c:131: undefined reference to `rt_task_delete'
obj/RT_DAQ.o(.text+0x32c):/root/test/RT_DAQ.c:132: undefined reference to `rt_shm_free'
obj/RT_DAQ.o(.text+0x338):/root/test/RT_DAQ.c:133: undefined reference to `rtf_destroy'
obj/RT_DAQ.o(.text+0x344):/root/test/RT_DAQ.c:134: undefined reference to `rtf_destroy'
obj/RT_DAQ.o(.text+0x34c):/root/test/RT_DAQ.c:135: undefined reference to `rt_task_delete'
collect2: ld returned 1 exit status
make: *** [KDEMenu] Error 1

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Please let me know if you have any other ideas.

-Chris

[jacek]

OK, I've read a bit about this RTAI thing and it looks like you need two things:

1. a kernel module that will implement the real-time part of your application,
2. an user-space application that will serve as a front-end.

You can't link them together. Luckily RTAI provides some means of communication between the module and application. Maybe this guide will be helpful.

[zielchri]

Thanks for the reply.

I've read through that document as well as many others, so maybe I need to clarify the issue a little further.

I can compile using a makefile a command based program using rtai and comedi by itself (with no qt involved). The makefile I use is below:

LINUXINC= /usr/src/linux/include
RTAIINC= /usr/realtime/include
COMEDIDIR= /devel/comedi-0.7.68/include
FLAGS=-g -D__KERNEL__ -DMODULE -O2
INCLD= -I$(LINUXINC) -I$(RTAIINC) -I/opt/kde3/include -I/usr/lib/qt3/include -I/usr/include -I$(QTDIR)/include
QT3LIB = /usr/lib/qt3/lib
QT3INC = /usr/lib/qt3/include
 
RT_DAQ:RT_DAQ.c RT_user
	gcc  -c $(FLAGS) $(INCLD) -I$(COMEDIDIR) RT_DAQ.c
 
RT_user:RT_user.cpp
	g++ $(INCLD) -L$(QT3LIB) -I$(QT3INC) -I$(COMEDIDIR) -l comedi -O2 -o RT_user RT_user.cpp -lm -lqt

LINUXINC= /usr/src/linux/include
RTAIINC= /usr/realtime/include
COMEDIDIR= /devel/comedi-0.7.68/include
FLAGS=-g -D__KERNEL__ -DMODULE -O2
INCLD= -I$(LINUXINC) -I$(RTAIINC) -I/opt/kde3/include -I/usr/lib/qt3/include -I/usr/include -I$(QTDIR)/include
QT3LIB = /usr/lib/qt3/lib
QT3INC = /usr/lib/qt3/include

RT_DAQ:RT_DAQ.c RT_user
	gcc  -c $(FLAGS) $(INCLD) -I$(COMEDIDIR) RT_DAQ.c

RT_user:RT_user.cpp
	g++ $(INCLD) -L$(QT3LIB) -I$(QT3INC) -I$(COMEDIDIR) -l comedi -O2 -o RT_user RT_user.cpp -lm -lqt

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RT_user.cpp is the user space program and RT_DAQ.c is the kernel space program.

Okay, so it might be that I'm an electrical engineer and not a computer science major, but I thought I read that file as the RT_DAQ compiles in terms of RT_DAQ.c and RT_user, which is the program compiled in the lines below it.

I guess I always thought "RT_DAQ:RT_DAQ.c RT_user" was how the two files got linked together. Is this wrong?

If so, can I just use qmake with the suggestions already stated but leave out RT_DAQ.c in the .pro file because qmake won't connect the two together? That is, if I use qmake to generate RT_user, can I use another makefile I create myself (like the one above) to actually compile the kernel program with the RT_user compiled?

Sorry for my ignorance, but I hope that made sense. I'm thinking I can do this because the compiler doesn't appear to have any problems with the user space source code, just the kernel space program. Please let me know what you think.

-Chris

[jacek]

I guess I always thought "RT_DAQ:RT_DAQ.c RT_user" was how the two files got linked together. Is this wrong?

Yes, it is. That's only a rule that tells the make program that the "RT_DAQ" target depends on "RT_DAQ.c" and "RT_user" (i.e. it states that if one of them has been changed the RT_DAQ should be rebuilt).

Since you are building two separate things, you could use the subdir template:

Suppose your project directory has following layout:

./rt.pro
./frontend/rt_user.pro
./frontend/RT_user.cpp
./module/Makefile
./module/RT_DAQ.c

Where rt.pro is:

TEMPLATE = subdirs
SUBDIRS += frontend module

TEMPLATE = subdirs
SUBDIRS += frontend module

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./frontend/rt_user.pro is:

TEMPLATE = app
TARGET = ../bin/rt_client
MOC_DIR = ../build
OBJECTS_DIR = ../build
INCLUDEPATH += /usr/src/linux/include \
               /usr/realtime/include \
               /devel/comedi-0.7.68/include \
               /opt/kde3/include
LIBS += -L/opt/kde3/lib -lkdeui -lkdecore \
        -L/devel/comedi-0.7.68/lib -lcomedi
SOURCES += RT_user.cpp

TEMPLATE = app
TARGET = ../bin/rt_client
MOC_DIR = ../build
OBJECTS_DIR = ../build
INCLUDEPATH += /usr/src/linux/include \
               /usr/realtime/include \
               /devel/comedi-0.7.68/include \
               /opt/kde3/include
LIBS += -L/opt/kde3/lib -lkdeui -lkdecore \
        -L/devel/comedi-0.7.68/lib -lcomedi
SOURCES += RT_user.cpp

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and ./module/Makefile is:

LINUXINC= /usr/src/linux/include
RTAIINC= /usr/realtime/include
COMEDIDIR= /devel/comedi-0.7.68/include
FLAGS=-g -D__KERNEL__ -DMODULE -O2
INCLD= -I$(LINUXINC) -I$(RTAIINC) -I/usr/include
 
RT_DAQ: RT_DAQ.c
    gcc  -c $(FLAGS) $(INCLD) -I$(COMEDIDIR) RT_DAQ.c

LINUXINC= /usr/src/linux/include
RTAIINC= /usr/realtime/include
COMEDIDIR= /devel/comedi-0.7.68/include
FLAGS=-g -D__KERNEL__ -DMODULE -O2
INCLD= -I$(LINUXINC) -I$(RTAIINC) -I/usr/include
 
RT_DAQ: RT_DAQ.c
    gcc  -c $(FLAGS) $(INCLD) -I$(COMEDIDIR) RT_DAQ.c

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If all paths are correct and I haven't forgot anything it should build without any problems.

[zielchri]

Hey thanks for the reply. But can you tell me how I would go about compiling that? Would I start by using "qmake rt.pro -o Makefile" then move into the frontend directory and use "qmake rt_user.pro -o Makefile" then run the rt.pro makefile? Please let me know.

[jacek]

But can you tell me how I would go about compiling that?

It should be enough to run "qmake && make" in the directory where rt.pro is located (if it doesn't want to work, you will have to run qmake in the frontend directory too).

[zielchri]

Hey thanks guys, it works now!!!!

For anybody else interested or is having the same problem, the solution was to follow each suggestion listed above, as well as write a short script to copy the object file of the kernel program and the compiled program (above rt_client) into a seperate folder. There I also included a .runinfo file, which is necessary to load the real-time parts of rt_client (otherwise when I just ran ./rt_client no real-time sampling occured in my system). Once those three files were there I typed rtai-load at the command prompt (while in that folder) and the program ran just like it should!

[jacek]

as well as write a short script to copy the object file of the kernel program and the compiled program (above rt_client) into a seperate folder.

You can tweak above files to do the same automatically.