Re: [Outreachy kernel] IIO Experiment #1 Build Dummy Help

From: Daniel Baluta <daniel.baluta@intel.com>
To: SIMRAN SINGHAL <singhalsimran0@gmail.com>
Cc: outreachy-kernel <outreachy-kernel@googlegroups.com>,
	 Elizabeth Ferdman <gnudevliz@gmail.com>,
	Daniel Baluta <daniel.baluta@intel.com>,
	 Alison Schofield <amsfield22@gmail.com>
Subject: Re: [Outreachy kernel] IIO Experiment #1 Build Dummy Help
Date: Thu, 23 Mar 2017 16:39:35 +0200	[thread overview]
Message-ID: <CAEnQRZCp95E5cjog6ws8+Jyy3RY35G_OZrXapWaz9wA9PxiGsw@mail.gmail.com> (raw)
In-Reply-To: <3ad92cf5-564b-4150-aa8e-89336e617679@googlegroups.com>

On Thu, Mar 23, 2017 at 4:21 PM, SIMRAN SINGHAL
<singhalsimran0@gmail.com> wrote:
>
>
> On Monday, October 17, 2016 at 5:19:49 AM UTC+5:30, Eva Rachel Retuya wrote:
>>
>> On Sun, Oct 16, 2016 at 02:23:58PM -0700, Elizabeth Ferdman wrote:
>> > On Sun, Oct 16, 2016 at 10:04:27AM +0800, Eva Rachel Retuya wrote:
>> > > Hi Liz,
>> > >
>> > > On Sat, Oct 15, 2016 at 02:07:49PM -0700, Elizabeth Ferdman wrote:
>> > > ----massive snip----
>> > > > I think that running $ make -j2 && sudo make modules_install could
>> > > > solve
>> > > > this problem? If I can't do insmod can I just do modprobe?
>> > > >
>> > >
>> > > modprobe is OK to use.
>> > >
>> > Thanks, I used modprobe and the modules were loaded.
>> >
>> > I'm running into this issue in Task 01
>> > When I do 'ls -l /config/iio/devices/dummy/' the terminal just hangs. I
>> > closed the terminal and tried it a few more times but it was just
>> > freezing and I had to xkill it. I have been following the tutorial. I
>> > mounted the configfs at /config, made the modules, loaded them, ran
>> > mkdir /config/iio/devices/dummy/my_dummy_device.
>> >
>>
>> Hi,
>>
>> I suggest to do 'make clean' again and start from scratch.
>> Run 'make menuconfig' and make sure the settings look like this:
>> {*} Industrial I/O support ---> (instead of module, make this built-in,
>> use 'y' instead of 'm')
>> <Descend this option where you'll configure configfs, dummy, etc>
>> {*} Enable IIO configuration via configfs (use 'y' instead of 'm')
>> <M> Enable software IIO device support
>> <M> Enable software triggers support
>>
>> Under IIO dummy driver:
>> <M> An example driver with no hardware requirements
>> [*] Event generation support
>> [*] Buffered capture support
>>
>> Compile and install, then boot to that kernel and test if it works.
>
>
> Hi,
>
> I am able to insert module iio_dummy_evgen.ko but when I run
> $ sudo insmod iio_dummy.ko
>
> I got the following error:
> insmod: ERROR: could not insert module iio_dummy.ko: Unknown symbol in
> module
>
> And in dmesg I am getting following error:
> iio_dummy: Unknown symbol iio_register_sw_device_type (err 0)
>
> Any Idea?

Find the .c file which exports this symbol. Then look into the Makefile from the
same directory where you found the .c file and find the CONFIG_ symbol which
compiles the .c file.

Daniel.