[Xenomai] Cross-compiling RTDM driver errors

[Xenomai] Cross-compiling RTDM driver errors

[Stefan Videv]

Hi,

I am trying to cross compile a driver that I wrote which is very similar 
to the one provided in the examples (tut02-skeleton-drv). I've basically 
changed the write function to do what I am interested in doing, 
everything else is the same (however I am not providing a read function).

During compilation I get the following error:

FATAL: modpost: GPL-incompatible module vlcTxDriver.ko uses GPL-only 
symbol 'rtdm_dev_unregister'

What's that supposed to mean, and how do you get around it?

I am using the Makefile provided with the examples and compiling like so:

make XENO=/media/rootfs/usr/xenomai/ ARCH=arm 
CROSS_COMPILE=arm-linux-gnueabi- KSRC=~/beagle/linux/ 
DESTDIR=/media/rootfs ADD_CFLAGS=-I/usr/arm-linux-gnueabi/include


Thanks!

-- Stefan

Re: [Xenomai] Cross-compiling RTDM driver errors

[Stefan Videv]

On 11/05/2012 05:13 PM, Stefan Videv wrote:
> Hi,
>
> I am trying to cross compile a driver that I wrote which is very 
> similar to the one provided in the examples (tut02-skeleton-drv). I've 
> basically changed the write function to do what I am interested in 
> doing, everything else is the same (however I am not providing a read 
> function).
>
> During compilation I get the following error:
>
> FATAL: modpost: GPL-incompatible module vlcTxDriver.ko uses GPL-only 
> symbol 'rtdm_dev_unregister'
>
> What's that supposed to mean, and how do you get around it?
I answered my own question just now -- I've forgotten to define the 
module licence correctly. Having done that I end up with some undefined 
symbols, just like when trying to compile the POSIX examples.

Here's what I get:

WARNING: "pse51_shm_close" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] 
undefined!
WARNING: "munmap" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
WARNING: "mmap" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
WARNING: "open" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!

Any help is appreciated! Thanks!

>
> I am using the Makefile provided with the examples and compiling like so:
>
> make XENO=/media/rootfs/usr/xenomai/ ARCH=arm 
> CROSS_COMPILE=arm-linux-gnueabi- KSRC=~/beagle/linux/ 
> DESTDIR=/media/rootfs ADD_CFLAGS=-I/usr/arm-linux-gnueabi/include
>
>
> Thanks!
>
> -- Stefan

Re: [Xenomai] Cross-compiling RTDM driver errors

[Stefan Videv]

On 11/05/2012 05:19 PM, Stefan Videv wrote:
> On 11/05/2012 05:13 PM, Stefan Videv wrote:
>> Hi,
>>
>> I am trying to cross compile a driver that I wrote which is very 
>> similar to the one provided in the examples (tut02-skeleton-drv). 
>> I've basically changed the write function to do what I am interested 
>> in doing, everything else is the same (however I am not providing a 
>> read function).
>>
>> During compilation I get the following error:
>>
>> FATAL: modpost: GPL-incompatible module vlcTxDriver.ko uses GPL-only 
>> symbol 'rtdm_dev_unregister'
>>
>> What's that supposed to mean, and how do you get around it?
> I answered my own question just now -- I've forgotten to define the 
> module licence correctly. Having done that I end up with some 
> undefined symbols, just like when trying to compile the POSIX examples.
>
> Here's what I get:
>
> WARNING: "pse51_shm_close" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] 
> undefined!
> WARNING: "munmap" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
> WARNING: "mmap" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
> WARNING: "open" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
>
> Any help is appreciated! Thanks!
I've somewhat answered my questions again:

http://www.xenomai.org/pipermail/xenomai-help/2011-12/msg00014.html

However, I still do not understand how do you go about enabling these 
features (i.e. what to enable when configuring my kernel). Also, I have 
a user space program that I then converted to the kernel module that I 
am now trying to compile. That runs perfectly fine on my kernel. Is that 
possible? Is the kernel missing support for these operations, but you 
can do that fine from user space?

Thanks, again!

-- Stefan
>
>>
>> I am using the Makefile provided with the examples and compiling like 
>> so:
>>
>> make XENO=/media/rootfs/usr/xenomai/ ARCH=arm 
>> CROSS_COMPILE=arm-linux-gnueabi- KSRC=~/beagle/linux/ 
>> DESTDIR=/media/rootfs ADD_CFLAGS=-I/usr/arm-linux-gnueabi/include
>>
>>
>> Thanks!
>>
>> -- Stefan
>

Re: [Xenomai] Cross-compiling RTDM driver errors

[Stefan Videv]

On 11/05/2012 05:33 PM, Stefan Videv wrote:
> On 11/05/2012 05:19 PM, Stefan Videv wrote:
>> On 11/05/2012 05:13 PM, Stefan Videv wrote:
>>> Hi,
>>>
>>> I am trying to cross compile a driver that I wrote which is very 
>>> similar to the one provided in the examples (tut02-skeleton-drv). 
>>> I've basically changed the write function to do what I am interested 
>>> in doing, everything else is the same (however I am not providing a 
>>> read function).
>>>
>>> During compilation I get the following error:
>>>
>>> FATAL: modpost: GPL-incompatible module vlcTxDriver.ko uses GPL-only 
>>> symbol 'rtdm_dev_unregister'
>>>
>>> What's that supposed to mean, and how do you get around it?
>> I answered my own question just now -- I've forgotten to define the 
>> module licence correctly. Having done that I end up with some 
>> undefined symbols, just like when trying to compile the POSIX examples.
>>
>> Here's what I get:
>>
>> WARNING: "pse51_shm_close" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] 
>> undefined!
>> WARNING: "munmap" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
>> WARNING: "mmap" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
>> WARNING: "open" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
>>
>> Any help is appreciated! Thanks!
> I've somewhat answered my questions again:
>
> http://www.xenomai.org/pipermail/xenomai-help/2011-12/msg00014.html
>
> However, I still do not understand how do you go about enabling these 
> features (i.e. what to enable when configuring my kernel). 
I've enabled shared memory support from the POSIX options for Xenomai. 
That takes care of the first 3 warnings.

However, I am still having the last one. I am trying to use this 
particular open() function:

http://pubs.opengroup.org/onlinepubs/000095399/functions/open.html

to be able to write to /dev/mem

-- Stefan

> Also, I have a user space program that I then converted to the kernel 
> module that I am now trying to compile. That runs perfectly fine on my 
> kernel. Is that possible? Is the kernel missing support for these 
> operations, but you can do that fine from user space?
>
> Thanks, again!
>
> -- Stefan
>>
>>>
>>> I am using the Makefile provided with the examples and compiling 
>>> like so:
>>>
>>> make XENO=/media/rootfs/usr/xenomai/ ARCH=arm 
>>> CROSS_COMPILE=arm-linux-gnueabi- KSRC=~/beagle/linux/ 
>>> DESTDIR=/media/rootfs ADD_CFLAGS=-I/usr/arm-linux-gnueabi/include
>>>
>>>
>>> Thanks!
>>>
>>> -- Stefan
>>
>

Re: [Xenomai] Cross-compiling RTDM driver errors

[Gilles Chanteperdrix]

On 11/05/2012 07:00 PM, Stefan Videv wrote:

> On 11/05/2012 05:33 PM, Stefan Videv wrote:
>> On 11/05/2012 05:19 PM, Stefan Videv wrote:
>>> On 11/05/2012 05:13 PM, Stefan Videv wrote:
>>>> Hi,
>>>>
>>>> I am trying to cross compile a driver that I wrote which is very 
>>>> similar to the one provided in the examples (tut02-skeleton-drv). 
>>>> I've basically changed the write function to do what I am interested 
>>>> in doing, everything else is the same (however I am not providing a 
>>>> read function).
>>>>
>>>> During compilation I get the following error:
>>>>
>>>> FATAL: modpost: GPL-incompatible module vlcTxDriver.ko uses GPL-only 
>>>> symbol 'rtdm_dev_unregister'
>>>>
>>>> What's that supposed to mean, and how do you get around it?
>>> I answered my own question just now -- I've forgotten to define the 
>>> module licence correctly. Having done that I end up with some 
>>> undefined symbols, just like when trying to compile the POSIX examples.
>>>
>>> Here's what I get:
>>>
>>> WARNING: "pse51_shm_close" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] 
>>> undefined!
>>> WARNING: "munmap" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
>>> WARNING: "mmap" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
>>> WARNING: "open" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
>>>
>>> Any help is appreciated! Thanks!
>> I've somewhat answered my questions again:
>>
>> http://www.xenomai.org/pipermail/xenomai-help/2011-12/msg00014.html
>>
>> However, I still do not understand how do you go about enabling these 
>> features (i.e. what to enable when configuring my kernel). 
> I've enabled shared memory support from the POSIX options for Xenomai. 
> That takes care of the first 3 warnings.
> 
> However, I am still having the last one. I am trying to use this 
> particular open() function:
> 
> http://pubs.opengroup.org/onlinepubs/000095399/functions/open.html
> 
> to be able to write to /dev/mem


You do not write to /dev/mem in a kernel module. You use ioremap.

-- 
                                                                Gilles.

Re: [Xenomai] Cross-compiling RTDM driver errors

[Stefan Videv]

On 11/05/2012 06:50 PM, Gilles Chanteperdrix wrote:
> On 11/05/2012 07:00 PM, Stefan Videv wrote:
>
>> On 11/05/2012 05:33 PM, Stefan Videv wrote:
>>> On 11/05/2012 05:19 PM, Stefan Videv wrote:
>>>> On 11/05/2012 05:13 PM, Stefan Videv wrote:
>>>>> Hi,
>>>>>
>>>>> I am trying to cross compile a driver that I wrote which is very
>>>>> similar to the one provided in the examples (tut02-skeleton-drv).
>>>>> I've basically changed the write function to do what I am interested
>>>>> in doing, everything else is the same (however I am not providing a
>>>>> read function).
>>>>>
>>>>> During compilation I get the following error:
>>>>>
>>>>> FATAL: modpost: GPL-incompatible module vlcTxDriver.ko uses GPL-only
>>>>> symbol 'rtdm_dev_unregister'
>>>>>
>>>>> What's that supposed to mean, and how do you get around it?
>>>> I answered my own question just now -- I've forgotten to define the
>>>> module licence correctly. Having done that I end up with some
>>>> undefined symbols, just like when trying to compile the POSIX examples.
>>>>
>>>> Here's what I get:
>>>>
>>>> WARNING: "pse51_shm_close" [/home/stefan/VLCTxDriver/vlcTxDriver.ko]
>>>> undefined!
>>>> WARNING: "munmap" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
>>>> WARNING: "mmap" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
>>>> WARNING: "open" [/home/stefan/VLCTxDriver/vlcTxDriver.ko] undefined!
>>>>
>>>> Any help is appreciated! Thanks!
>>> I've somewhat answered my questions again:
>>>
>>> http://www.xenomai.org/pipermail/xenomai-help/2011-12/msg00014.html
>>>
>>> However, I still do not understand how do you go about enabling these
>>> features (i.e. what to enable when configuring my kernel).
>> I've enabled shared memory support from the POSIX options for Xenomai.
>> That takes care of the first 3 warnings.
>>
>> However, I am still having the last one. I am trying to use this
>> particular open() function:
>>
>> http://pubs.opengroup.org/onlinepubs/000095399/functions/open.html
>>
>> to be able to write to /dev/mem
>
> You do not write to /dev/mem in a kernel module. You use ioremap.
>
Great point :) Everything works now (well apart from the fact that I am 
not sure I am writing to the correct registers when using ioremap and 
iowrite, but that's outside the scope of this mailing list :) ).

Thanks!

-- Stefan