[yocto] Kernel driver for Turbosight TBS6285 DVB card

[Chris Tapp]

On 21 Aug 2014, at 19:28, Bruce Ashfield <bruce.ashfield at windriver.com> wrote:

> On 14-08-21 04:17 AM, Chris Tapp wrote:
>> On 21 Aug 2014, at 05:08, Bruce Ashfield <bruce.ashfield at gmail.com> wrote:
>> 
>>> On Wed, Aug 20, 2014 at 4:11 PM, Chris Tapp <opensource at keylevel.com> wrote:
>>>> Hi Bruce,
>>>> 
>>>> Thanks for the feedback.
>>>> 
>>>> On 20 Aug 2014, at 03:08, Bruce Ashfield <bruce.ashfield at windriver.com> wrote:
>>>> 
>>>>> On 2014-08-19, 5:26 PM, Chris Tapp wrote:
>>>>>> I need to include the kernel driver for the Turbosight TBS6285 DVB card in an image.
>>>>>> 
>>>>>> The official bundle at http://www.tbsdtv.com/download/document/common/tbs-linux-drivers_v140707.zip includes the drivers and a load of other "stuff" (e.g. a full V4L build).
>>>>>> 
>>>>>> LinuxTV.org have the drivers extracted into a .tar.bz2 at (e.g.) http://linuxtv.org/downloads/drivers/linux-media-LATEST.tar.bz2, so I plan to use this as the download source.
>>>> This bit is wrong - I need to use the .tar.bz within the .zip.
>>>> 
>>>>>> So far I have a recipe which downloads from this URL and extracts the files into the work area and ${WORKAREA}/drivers/media includes a Makefile and Kconfig.
>>>>>> 
>>>>>> I've looked at the Yocto documentation, but this doesn't seem to be a good match for the "Out of tree" kernel module case.
>>>>> Hmm. At a glance, I'd say that it does sound like a typical out of
>>>>> tree module build.
>>>> Ah, ok - to my (untrained) eye the use-case looked completely different based on the example.
>>>> 
>>>>> Did you try adopting the meta-skeleton hello-mod recipe and point it
>>>>> at that source directory ?
>>>> I have now (with the above change). However, it looks as if something within the build is referencing the host file system when building.
>>>> 
>>>> I'm building for ValleyIsland 32-bit:
>>>> 
>>>>  1) If I configure the drivers for 32-bit there is a linker error complaining that elf 32 and elf 64 aren't compatible (host is 64 bit);
>>> Hmm. The target arch should be used for this build. Are you enabling a
>>> multi lib config
>>> as well ?
>> Not that I know of ;-)
>> 
>> The build uses a .version file to specify the kernel. The top makefile creates this using 'uname -r' by default. I can run 'make dir DIR="..." in do_configure() to specify the path to the yocto kernel files, which seems to fix this (after modifying another makefile, which prepends "../" to the DIR path).
> 
> Definite host contamination there. You likely want the code, but
> not the build infrastructure in this case.
> 
>> 
>>>  2) Everything appears to build if I target 64-bit, but the installer tries to modify /lib/modules/3.2.0-67/..., which is also part of the host.
>>> 
>>> Do the Makefile's that come in that archive (I haven't gone to look)
>>> have a custom
>>> install rule ? If so, that's likely the problem. If the kernel's build
>>> system is triggered
>>> (i.e. the makefile follows the conventions), everything will be
>>> installed to the proper
>>> location.
>> The installer uses DESTDIR to select the installation path - I've not worked out how this gets set yet or how I can set it from within my recipe.
>> 
>> Is there a trick I can use to get the kernel's build system to manage things?
> 
> In this case, you really need to replace (or patch) the existing Makefile
> that comes with the package.
> 
> The hello-mod example I pointed out has makefile that shows the right
> definitions to allow the kernel's build system to enter the directory, build
> and install the modules.

I've made some good progress, but still not quite there.

I've got a do_compile() that basically does:

  make DIR=${STAGING_KERNEL_DIR}

The appears to build the modules correctly - testing will tell ;-)

I've then got similar in do_install():

  make DIR=${STAGING_KERNEL_DIR} DESTDIR=${D}

That's 99% there - the modules get put in image/lib/modules/3.10.40-ltsi/...
They should be in image/lib/modules/3.10.40-ltsi-yocto-standard/... - not sure yet how to fix this one.

There is also a packaging QA issue causing a build failure (some files aren't used), but an INSANE_SKIP installed-vs-shipped fixes that one for now.

--

Chris Tapp
opensource at keylevel.com
www.keylevel.com